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rec.models.rockets FAQ Part 04 - Born Again Rocketeers

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Wolfram v.Kiparski

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Sep 26, 2000, 3:00:00 AM9/26/00
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Archive-name: model-rockets/BAR
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Last-modified: 1997 April 13
URL: http://dtm-corp.com/~sven/rockets/rmrfaq.toc.html

Rec.Models.Rockets Frequently Asked Questions: PART 4 OF 14

BORN AGAIN ROCKETEERS
----------------------------------------------------------
4.1 What the heck is a 'Born Again Rocketeer'?

A Born Again Rocketeer (BAR) is a person who started out in model
rocketry in their 'younger' days, dropped out of the hobby for some
number of years, and then came to their senses and got back into it.
BARs are noted for re-entering the hobby with extreme enthusiasm and
much deeper pockets than they had during their first encounter with
the hobby. Actually, the length of time spent away from the hobby is not as
important as the extreme enthusiasm that BARs have when getting back into
rocketry. It's like, we have to make up for lost time or something.
The editor of this FAQ is a BAR (and proud of it :-).

Paul Wolaver <pwol...@sybase.com> wrote this BAR observation:
Be prepared for the BAR phenomenon. Open your wallet. Write off your
weekends. Set aside a room in your house to build rockets.
Buy epoxy.

An informal survey of 49 Born-Again Rocketeers on r.m.r. yielded the
following information:

- average number of years away from the hobby - 18.6

- Why did you get back into rocketry?

The answers varied greatly, but these three were at the top:
1. Involvement with children (33%)
2. 'discovered' rec.models.rockets (12%)
3. wanted to get into HPR after seeing how much the hobby has
changed. (8%)

- current 'mode' of flying rockets
1. model rocketry (49%)
2. high power (20%)
3. high power 'lite' (10%)

- what did you fly first?

Seems like everyone did something different. Estes kits were the
overwhelming majority, with the Big Bertha, Alpha, Alpha III, and
Phoenix all being mentioned more than once or twice.

- what were your old favorites, way back when?

Again, everyone liked something different, and everyone had more
than one single favorite kit. Estes kits figured prominently in
the memories of the surveyed. The Big Bertha, Mars Lander, and
Orbital Transport kits were most popular. A few folks were Centuri
fans, with the Orion kit getting the most votes (2). A few
eschewed the kit scene completely, and someone recalled fond
memories of building ZnS rockets.

----------------------------------------------------------
4.2 I have been out of model rockets for many (i.e. <nn>+) years now.
What been happening in the hobby over the past couple of decades?
What's new? What's gone?

4.2.1 Who's Left, Who's Not & Who's New

To sum it up...

Gone: Centuri/Enerjet
Rocket Development Corporation
Space Age Industries
MPC rocket kits
Coaster
'S' Series (short) 18mm motors
Competition Model Rockets (CMR)
AVI motors
Camroc/Cineroc

Still here: National Association of Rocketry (NAR)
Estes
Flight Systems (maybe)

New: High Power Rocketry, with *BIG* rockets
Tripoli Rocketry Association
MANY new companies
Composite rocket motors are commonplace
Reloadable solid rocket motors
Hybrid rocket motors
Phenolic and fiberglass rocket components
Electronic altimeters, flight computers,....
Much improved rocketry simulation software
And a whole lot more.....

Basically, it's all pretty much the same, or totally different,
depending on your interests. Estes is still Estes. Most of their kits
are still the same materials, etc. The trend for the last 10 years has
been for Estes to sell simpler and simpler kits. There are lots of
plastic nose cones and fin units (already around when you were active
before). There are now kits with pre-slotted body tubes and plastic
fins (as in the Estes E2X series). Lot's of good stuff for beginners
and kids. Estes now makes engines in the 1/2A - D range, all black
powder. Estes has some Large Model Rocket offerings ready, as well.
Read below for details.

Flight Systems (FSI), another motor and kit manufacturer that got its
start in the late 60's, was reported in 1995 to have ceased its
model rocketry operations. They have restarted production in 1996, and plan
on being up to full production by 1997.

Centuri, sadly, 'went away' in 1980. Damon Industries bought both Estes
and Centuri in the 1970's. They operated both companies as independent
units for several years. Finally, Centuri was dissolved and its products
absorbed into Estes. Every now and then an old Centuri kit surfaces
under the Estes banner. An interesting piece of trivia is that the tax
and incorporation laws were more favorable in Arizona (home of Centuri)
than Colorado (home of Estes). So, Damon, on paper, had Centuri acquire
Estes, even though it was Centuri's operations that were eventually shut
down. Damon sold off Estes to a group of investors in the early 90's.

Now for 'who is new'. First, in model rocketry there is a new kid
on the block: Quest. This is Bill Stine, some ex-Centuri people
and others. They are a direct competitor to Estes. They have a line
of kits and engines (A-C). Good quality. Less expensive than Estes.

There are many other smaller companies making and selling model rocket
kits. See Part 02 of the FAQ for addresses. Custom Rockets is another
company with rocket kits similar to those offered by Estes and Quest.
Custom offers quality paper tube/balsa finned kits in the A-D power
range.

Aerotech, LOC/Precision, Rocket R&D, Public Missiles, and North Coast
Rocketry are some new names in the business. These companies cater to both
larger model rocket and high power rocket markets. Estes bought manufacturing
rights to all NCR products in 1995. Estes has announced a line of F/G
rockets (based on NCR designs) to be released in 1996. Estes
may also release a small line of F and G composite motors by 1997. A
newer outfit, Rocket R&D, bought out THOY and another smaller HPR
manufacturer, Cluster R.

Aerotech manufactures both single-use and reloadable composite rocket
motors ranging from C to M total impulse classes. They also offer a few
kits designed for E to G engines.

A couple of outfits make kits using newer technology materials, including
phenolics, fiberglass, and composites. These include Public Missiles (PML),
Rocketman and Dynacom. Be prepared to pay more dollars for the more
advanced materials. A $60-75, 4" diameter, heavy paper tube based kit,
such as manufactured by LOC, might cost $100-125 in a phenolic based
kit, such as produced by PML. A Dynacom fiberglass kit of the same
size might cost closer to $350.

If you were into rocketry in the early 1980's then you probably remember
AAA Model Aviation Fuels. They're still here, with a line of HPR and
Large Model Rocket kits.

If you were into competing you might have been familiar with Competition
Model Rockets (CMR). They are now defunct but there are constant rumors
of a rebirth 'sometime in the near future'. Other companies have stepped
in to fill the space left by the exit of CMR. See the section
'Competition' for some names and addresses. Three new companies are
Apogee Components, Qualified Competition Rockets, and Eclipse Components.
Apogee was started by long-time rocketeer Ed LaCroix. QCR was started by
another long-time rocketeer, Kenneth Brown. Ed has now joined the Aerotech
team and Apogee is now run by Timothy Van Milligan. A new company,
Eclipse Components, has picked up some of the Apogee Components line, except
for the motors. Apogee is still selling those, as well as a new line of kits.
Pratt Hobbies has picked up some of the old CMR product line, and has already
made the CMR egg capsules and nose cones available again.

A lot of the 'neat' Estes kits of the 60's and 70's are no longer
available. However, Estes is bringing them back (one by one) in so-
called, 'limited run collector series'. The original 'Mars Snooper' and
'Maxi Honest John' kits have been re-issued, so far, along with the
Star Trek and Star Wars kits. More releases are supposed to be
forthcoming. WARNING: Be prepared to pay a much higher
price for these re-released kits. Remember that inflation has led to
some items having much higher prices now than in the mid 60's and 70's. No
doubt Estes will take advantage of the demand for the re-released kits,
as well, and charge an additional premium.

4.2.2 Changes in Motor Technology

The big changes have come in motors. Expendable composite fuel motors
are now available in B-G range for model rockets. These motors
use ammonium perchlorate for oxidizer and rubber as the fuel, similar to
the rocket boosters on the space shuttle, allowing them to pack two to
three times the power in the same space as a black powder motor. The B
motors from Apogee are the same size as Estes mini-motors (13x45mm).
The C motors (also from Apogee) are 18x50mm, while the D motors are the same
size as Estes A-C motors (18x70mm). The D is a full D (rated at 20
Newton-seconds versus the Estes 24x70mm D of about 17 N-s). E motors range
in size from 18x70mm to 29x124mm. All of the motors give Estes kits an incredible
ride, if the models hold together. These kits require stronger construction
methods and materials than typical model rockets. Put an Aerotech D21
in your old Big Bertha at your own risk!! You're might end up with a
model with no fins (i.e., a complete 'shred').

Another new trend is 'reloadable' motor technology. With reloadables
you have a metal motor casing that you manually reload with solid fuel
pellets, delay and ejection charge for each flight. The casing is
reusable. Reloadable motors are available in everything from 18x70 mm
(with D - E power), 24x70mm, (with D - F power), 29mm, 38mm, and much
larger. Again, you can get all the way up to 40,000+ Newton-seconds of
total impulse.

The latest technology to hit the High Power rocket scene is the hybrid
rocket motor. Hybrid motors use components from both liquid and solid
ful rocket motors. Two companies have currently certified hybrid motors
with Tripoli, Aerotech and Hypertek. The advantage of hybrid motors is
that they use totally inert fuel grains, such as a cast polymer plastic
or compressed paper pulp, which do not have any DOT or ATF restrictions.
With both motors, nitrous oxide is used for the oxidizer.

4.2.3 Competition

One notable difference between the time I left the hobby (late 1970s) and
today is that competition rocketry is not as popular as it once was. It
used to be that one would see 30 or more people at an NAR regional, but
today it sometimes seems like you are lucky if you get enough people to show
up. Because I got back in to the hobby to fly competition, I am concerned
about the apparent loss of interest in competition rocketry.
Still, competition is NOT dead, no way. Yearly NARAMs are still held,
and are well-attended. About half of the NAR sections still host meets,
or have members that fly competition. The rest fly sport and/or high power
rocketry only.

4.2.3 High Power Rocketry

Now there is also HIGH power rocketry (HPR). These are rockets with
motors up to type O (with greater than 40,000 Newton seconds of impulse).
There has been a lot of discussion about high power recently. You have to
be a member of either the NAR or Tripoli to fly rockets with H motors or
above. To fly with H or above both organizations require that you be
'certified' by safely demonstrating a successful flight with a high power
model in the presence of one or more 'qualified' members of the
organization. There is now a HPR safety code as well as the original
model rocketry safety code. There are expendable and reloadable
(discussed below) HPR motors available. They are increasingly
expensive as the power goes up ( $13 for a G up to hundreds of dollars
for a really big (O) motor). High power rockets start where model
rockets leave off (i.e., > 1500 grams). High power models weighing
more than 50 pounds are not uncommon. The record weight for a high
power flight is over 1000 pounds.

Oh, yes, HPR requires a duly authorized, signed-in-blood (in triplicate,
etc.) FAA waiver for each day you wish to fly. It is ILLEGAL to fly
high power rockets without a proper waiver. See Part 10 of this FAQ for more
information on FAA waivers.

You will also need to get a Federal Low Explosives Users Permit from the
BATF. More on this below, and a lot more in Part 1 of this FAQ.

4.2.4 Electronics Advancements

Advances in electronics technology have created many opportunities for
new ideas in consumer rocketry. Electronic ignition of upper stages of
multi-staged rockets is now common. Several altimeters more recording
maximum altitude are available. Electronic deployment of recovery
devices, as well as deployment based on altitude, is now practical.
The FAQ section on High Power Rocketry has more to say about this.
See Part 02 of this FAQ for addresses of some companies selling
rocketry electronics.

4.2.5 Regulations, Regulations, Regulations

There is some good news and some bad news concerning rules and
regulations relating to consumer rocketry. On the positive side, you
can now buy up to G power motors in most states. Also, some states, such
as New Jersey, have recently relaxed restrictions on model rockets.
California still has some of the most restrictive regulations in the country.
The BATF and DOT have both become quite interested in high power rocketry and
have begun enforcing shipping and explosives regulations. Read the current
regulatory summary in Part 1 of this FAQ.
----------------------------------------------------------
4.3 Are my old rocket kits worth anything today?

With all of the BARs coming back into rocketry, many wanting to rebuild
their favorite kits from the days of their youth, models rockets
have become 'collectable'. In fact, the demand for some classic kits has
gotten quite high. The explosive growth of the internet has helped
fuel several recent 'classic kit' auctions. Model rocket kits from the
late 60's and early 70's can still be found, but be prepared to pay
quite a premium. It isn't unusual to see what was a $5 kit from the early
70's going for $50 or more in an auction. Remember the 1/70 scale Estes
Estes Saturn 1B? It cost $11 in 1970, $15 in 1977. If you bought one
today at a model rocket auction, it is doubtful that $200 would get it.
How about the Maxi Brute Pershing 1A, which sold for $17 in 1977?
That kit, in good condition, might bring over $150 today.

Old kits that are still in their unopened, original packaging, might be
worth something. Once you open the package, the value drops. Missing or
partially constructed pieces lower the value even further.
So, all you BARs with old kits up in the attic might want to think
twice before ripping open the boxes and finally building that
Orbital Transport you got on your 12th birthday.

Opinions about the collectibility of old kits varies on r.m.r. Some frown
on collecting kits, and feel the rocket should be built and flown for
maximum enjoyment. Some would consider building the old kit a great loss.
Others take a middle road, and "clone" the kit - produce a duplicate, and
keep the original. Still others create scaled-up versions of old kits for
HPR flying fun. Regardless of what you do with it, old kits can be a lot
of fun, and there is even a magazine devoted to collecting old kits
(see Part 2 of this FAQ under books and magazines).

Those interested in cloning an old kit should check out the PLANS
subdirectory of the r.m.r. sunsite archive.

http://sunsite.unc.edu/pub/archives/rec.models.rockets/PLANS

Plans for old kits not in the archive are out there, usually just for
the asking. Post a request Chances are someone has plans for that
favorite oldie.

----------------------------------------------------------
4.4 Where can I find plans of old kits?

Plans of old kits are available. The r.m.r. sunsite archive has a few
old kit plans, and hopefully, there will be more in the future.

Old kit plans available on the sunsite archive are:
Estes Avenger (2 stage model)
Estes Cherokee-D (first D motor kit for many)
Estes Cobra (3 engine cluster)
Estes Drifter (competition parachute duration model)
Estes Farside (big 3 stage model)
Estes Gyroc (gyro-recovery model)
Estes Mark (classic model, essentially the same as a Mark II)
Estes Nighthawk (canard boost glider)
Estes Pegasus (scale-up plans)
Estes Ranger (3 engine cluster version of a Big Bertha)
Estes Scout (classic, one of Estes first models)
Estes Sprite (ring tail, mini-model)
Estes Starlight (unique design)
Estes Trident (old timer favorite)
Estes X-Ray (classic payloader)

Centuri Payloader II (classic beginners kit)

To get to the r.m.r. plans archive, try:

http://sunsite.unc.edu/pub/archives/rec.models.rockets/PLANS

http://www.cmass.org:8000/sunsite.unc.edu/PLANS

Other sources:

Doug Holverson scanned the paper shrouds of:

Centuri Vulcan
Centuri X-24 Bug

You can find them on his web site:
http://www.probe.net/~dholvrsn/fanghome.html

Estes Mars Lander plans online:

Richard Pitzeruse <rmpi...@mailbox.syr.edu> tells us:
OK folks, I FINALLY got the Mars Lander plans on my webpage.
They are scanned in at 300 dpi, 1 bit/pixel. They are saved as
tiff files (uncompressed) and then zipped into 2 different files.
Feed back is welcome and encouraged!
To get directly there, point your browser at...
http://128.230.82.205/RocketPics/plans/lander.html

List of every Estes kit ever made:

Tom McAtee <m21...@SL1001.mdc.com> wrote:
OK! I uploaded it to Sunsite...
The file is called ekdir.txt (for Estes Kit Directory)...

http://suniste.unc.edu/pub/archives/rec.models.rockets/LISTS/ekdir.txt

Jim Zalewski's site:

Jim <ji...@rust.net> tells us:
I just added some plans to my webpage.
Check them out and let me know what you think.
http://www.rust.net/~jimz/rp1.htm

Estes Andromeda plans online:

Lemeul E. Bryant <bry...@swbell.net> scanned the Andromeda decal sheet:
A scan of the Decal sheet for the Estes Andromeda is available at

http://www.geocities.com/CapeCanaveral/4491/index2.html

It's not best scan in the world but it is better then nothing.
The decal sheet measures about 3 1/2 by 13 1/2 inches.
The colors are red and white with a yellow background.

Estes Bomarc (Citation Series) plans online:

Ed Bertschy <bert...@azstarnet.com> put plans for the Bomarc online:

Complete full size templates of the Citation BOMARC wings, fins,
pods, ramjets, and re-engineered spine will be posted on my site
in .dxf and .bmp format for downloading. These measurements and plans
were drawn up from xeroxes of all the original parts. A color scan of
the decal sheet will be posted as well. You will find them at:

http://www.directfx.com/~ed.

---------------------------------------
Copyright (c) 1996 Wolfram von Kiparski, editor.
Refer to Part 00 for the full copyright notice.

Wolfram v.Kiparski

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Rec.Models.Rockets Frequently Asked Questions: PART 5 OF 14

MODEL ROCKETRY

----------------------------------------------------------
5.1 Can I legally fly model rockets in my state? What are the restrictions?

Several states still require some type of permit to fly model rockets.
The requirements vary greatly between the states. Also, local
municipalities are free to impose additional restrictions beyond those
defined in NFPA 1122 and any state laws. Check with your local fire
marshal for restrictions in your area. For example, the states
of Rhode Island, and California have stricter regulations than NFPA 1122.

----------------------------------------------------------
5.2 When do I need to notify the FAA before flying a large model rocket?

Large Model Rocket (LMR) is an FAA designation for a model rocket that is
between 454 grams (16 ounces) and 1500 grams of mass, including propellant,
-OR- contains more than 113 grams (4 ounces) but less than 125 grams of
propellant (all motors).

Please note that this definition is different from the definitions of a
model rocket found in NFPA 1122 and 1127-94. Some rockets may be defined
as LMR by the FAA, but are actually HPR according to the NFPA.

If you are planning to fly a Large Model Rocket as defined by the FAA, you
must notify the "FAA ATC facility nearest to the place of intended
operation"
24-48 hours before launch.

FAA notification requirements appear in FAR 101, and all of the pertinent
regulations appear in Part 10 of this FAQ.

A sample FAA notification form is available at the sunsite archive at:
http://sunsite.unc.edu/pub/archives/rec.models.rockets/FAA/FAR101.22.notice

From Bob Kaplow (robert...@hccompare.com)
"you need to find the right FAA office to notify. If you don't know
where they are, call 1-800-WX-BRIEF, and ask a briefer for the
proper place to call. Get an FAA map of your area. From that you can get
latitude/longitude, and radial/distance from your launch site to a nearby
VOR. Call 24-48 hours before the launch and give them the information.

I usually write a letter and mail/fax it to the folks first. That way
they have everything in writing. As a courtesy, I also call the closest
flight service station (FSS - ask the folks at 1-800-WX-BRIEF where they
are) and ask them to issue a locak NOTAM.
Get the "L" number as proof that you called."

----------------------------------------------------------
5.3 I have a son/daughter that is (less than 9) years old. Is this too
young for model rocketry? If not, are there any tips for helping
to keep their interest in the hobby?

Model rocket manufacturers all recommend adult supervision for young
children (usually, those under 12). Many parents have had great success
introducing these children to model rocketry. Here are a few of the tips
and suggestions posted to r.m.r:

From c...@rocket.sw.stratus.com (C. D. Tavares):
Children under 10 or 11 do best in the hobby when a parent participates
actively with them. Introduce them to simple, skill-level-1 kits with
plastic fin units. Build yourself a rocket at the same time, then go
out and fly them together.

From ja...@rml.com (Jack Hagerty):
My own experience with my son (now 5 1/2, we've been flying since he
turned 4) is not to expect too much sustained interest at a time. Even
though my son has a longer-than-normal attention span for his age
(he'll watch a whole two hour movie!) and loves the whole idea of
building and flying rockets, after 4 or 5 flights (approx. 1/2 hour)
he'd rather go play on the monkey bars at the adjacent school.
This is magnified if there are any kids his own age around (such as his
cousins that sometimes come with us).

From dw...@jarthur.Claremont.EDU:
Watching they should enjoy. Pressing the button they should enjoy.
Prepping with serious supervision. Building simple kits with some
supervision and a pre-launch check. There's a huge difference in
responsibility between kids. One thing to stress is that a lot of very
careful kids will get bored or get pressured by bored friends to do
stupid things when you're not around. I might not let kids have any
access to motors when unsupervised -- and there's no real reason why
that should cause them any trouble. It is possible to make safety fun,
you know. I think that's something that a lot of people miss -- if you
present things that way, it seems to work out. I don't have kids, but
I've got rocket launching friends who do.

From J.C...@ens.prime.com (Jim Cook):
I've successfully built an Athena and an America with a 7 year old.
The body tube is pre-painted, the decals are self-adhesive, and they
like the gold or silver chrome nose cone. You can build it in an hour
or two - just let them run around and call them over to help periodic-
ally - "glue here", "cut here", "hold this". They feel it's still
their rocket and that they helped. Estes new E2X series may also be
similarly suitable, but I haven't tried, yet [ed. note: the E2X
series go together with plastic model cement, such as Testors, not
white glue].

Estes' new E2X series is similar in construction to the Athena and
America - they can be built in an hour or two with kids.

Demo a range of motors. Go from 1/2A to A to B with a model to
show kids the difference.

Kids will invariably talk about launching them out of sight or
sticking a fireworks in them. Answer with, "yeah, but I wouldn't
want to wreck my model that I spent so much time building." Making
the kid answer forces him [or her] to think and teaches him [her]
to value his [her] possessions.

From buz...@netcom.com (Buzz McDermott):
When my 10 year old son and I started building rockets together about
2 1/2 years ago, we started with some of the level 1 Estes kits with
plastic fin units and nose cones, such as the Athena and Alpha III.
He has also built a couple of the Estes E2X series, which requires use of
plastic cement. He also likes the Quest Falcon (plastic fins) and Estes
Big Bertha (balsa fins) because they are both big enough to use C
motors and not loose the models.

My 7 year old daughter and I started building rockets about a year ago.
She prefers the Quest models with the colored parts. She also finds the
Quest parachutes, with their large adhesive connections for shroud
lines, easier to build. The Quest Falcon is a large, easy to build
model. Now she likes building some of the Level 1 kits with balsa fins.
She has built the Estes Alpha and Quest Sprint.

From jste...@software.mitel.com (John Stewart):
My daughter loves rocketry. She started when she was 3. Get colorful
rockets, build them yourself (e.g. the plastic Alpha III), and don't
fly them too high. (50-100' is more than fine) Let the child count to 5
(or try to!!) and push the button. Let them recover the rockets. Have
say, 5 to 10 rockets loaded, ready to go when heading out. Launch them,
and untangle/fix them either at the field, or at home later, depending
on the child's mood. My 4-3/4 year old daughter is looking forward to
launching, possibly this weekend. We spent a year in New Zealand, but
she still knew all about the rockets, the parachutes, the streamers...

From r...@cyclops.micr.Virginia.EDU (Robert Sisk):
People interested in easy to build model rocket kits for the younger
crowd should check out QUEST models. Some of the parts are color
coded (centering rings, engine blocks, engine mount tube) and the fins
of some models are plastic. Some of the fins are supplied as a single
unit that you glue into place. Fast, easy, and with little or no
sanding!

From wa...@pen.k12.va.us (Tony Wayne):
I reconstructed my launcher so that me 2.5 year can
launch the rocket. The launcher is homemade and uses a shorted
out 1/8 mini plug for the safety key. For my son, I attached an
8 foot loop of wire with each end attached to the poles of the
mini plug. In the middle of the wire loop is a film canister
with a push button. To launch the rocket I have to push the
button on the launcher and my son has to push his button too!
(When connecting the igniter to the launcher, I carry his
launch button with me.)

He practicing counting by leading the countdown. (Q: Is
"bi-leven" greater than or less than 4?) He checks the airspace
as well. ("Look boss! De'plane.") Also when we go to the field,
my rockets are ready launch. For about 20 minutes things
happen fast. When we are done there are rockets littering the
field. We then fetch them. (He "flies" a few of them back to
the pad.) His mom has to come too as diversion after fetching
so I can prep and go again.
----------------------------------------------------------
5.4 Is there any way I can buy model rocket kits, parts and engines at less
than full retail?

Three mail order houses have been recommended several times by posters to
r.m.r. They are Belleville Wholesale Hobby, Magnum Rockets Hobbies and
More, and Mountainside Hobbies. Belleville sells MRC at 40% off list,
Custom Rockets at 35% off list, and Estes at 30% off list. There is a
minimum order requirement. Magnum and Mountainside sell most all of the
major model and high power rocket lines. Both Estes and Aerotech model
rocket motors and reloads are sold. They both advertise Estes at 28-33% off
of list. Magnum will also discount educational sales (such as to schools,
Scouts, YMCA, etc.) at up to 40% off of list.

Another potential source for a large discount, if you are buying several
hundred dollars worth of parts at one time, is America's Hobby Center.
They offer discounts of up to 40% off of Estes' list price on orders of
over $400.

There are several other mail order sources that sell at discount. Some
of the smaller
manufacturers/suppliers of model rocketry kits and supplies are a
substantial bargain.
For the addresses of the sources listed above, and addition sources,
refer to the
'Names and Addresses' section of this FAQ (PART 2). Shop around.
There are bargains to be found.

If you do a fair amount of flying, Estes sells a 24-pack of engines called
the Flight Pack. It comes with 6 A8-3, 6 B6-4, 6 C6-5, 6 C6-7, recovery
wadding and igniters. It generally retails between $32-36, which is less
than the list price of the materials included. This can also be purchased
at an additional discount from some mail order houses. Estes also sells
'bulk packs' of 24 A8-2 or B6-4 or C6-5 motors.

Quest motors have been recommended by several r.m.r posters. At the
present time, they retail at less than the Estes equivalents. They can
also be purchased direct from Quest 'bagged' in quantities of 10 or more.
'A' motors can get to less than $1 ea. when bought 50 or more at a time.
'C' motors get down to around $1.25.

You might also investigate your local NAR section, if one is located
convenient to you. Clubs such as NAR sections often arrange discounts
with local hobby merchants. Several of the clubs also have at least
one member selling parts and supplies at discount, mostly to the
club members.
----------------------------------------------------------
5.5 I've had a large number of motors CATO recently. The engines are only
about 2 years old. I've had them stored in my (attic/garage/basement).

From J.C...@ens.prime.com (Jim Cook):
Black powder motors tend to suffer catos when they are temperature
cycled. If you expose them to heat, be it storing them in the attic,
on your car's dashboard, or in your metal range box in the hot sun on
the launch field, you may have problems. The engine expands with the
heat, but when it cools, the propellant separates from the casing
inside This causes the propellant to burn faster due to burning on the
side generating more pressure than was designed for, and ...boom...

Storing black powder motors in a damp basement can cause the compressed
clay nozzles to soften and also blow out. If you must store your motors
in a damp/humid area, put them in a zip lock plastic bag.

[Note: There is an excellent article by Matt Steele in the May/June 1992
issue of Sport Rocketry. This article goes into the
theoretical reasons why black powder model rocket motors fail]
----------------------------------------------------------
5.6 Is it safe to use my old rocket engines from <nn> years ago?

From J.C...@ens.prime.com (Jim Cook):
I've had properly stored engines from 1972 and 1975 work just fine.
If you suspect a motor, fire it by burying it in the ground with just
the nozzle showing, pointing up and use your launch system to ignite it
as usual. [Note: be sure and stand at least 15-20 feet away from the
motor when you fire it: Buzz]
----------------------------------------------------------
5.7 What's a good way to find other rocket enthusiasts in my area? How
can I found out about local rocket clubs?

Post a message on r.m.r. You might find someone there who lives close to
you, or knows someone who does. Check out Part 03 of this FAQ.

A list of NAR sections (clubs) is kept at the NAR web site: www.nar.org

The NAR sends a complete list of its local sections (NAR sanctioned
clubs) with each new member's information packet. If there isn't
a sanction near you, they can send members a list of other NAR members
in your area, so that you can form your own section.
----------------------------------------------------------
5.8 Are the Aerotech composite motors the same size as Estes/MRC/Quest
motors?

Aerotech makes the following 'standard' retail motors in -4 and -7
second delays. The first two motors are the same size as Estes A-C motors.
The next two are the same size as Estes D motors. There are some other
24mm motors that are available from Aerotech that are longer than
Estes D motors. Some of these 'non-standard' Aerotech 24mm motors are
listed
after the four 'standard' ones. The F and G motors may be obtained from
some dealers and mail order sources, but are not packaged for retail sale.

Motor Size Power Same Size As
D21 18x70mm 20NS Estes/Quest/MRC A-C
E25 18x70mm 22NS Estes/Quest/MRC A-C

E15 24x70mm 40NS Estes D motor
E30 24x70mm 40NS Estes D motor

F32 24x124mm 80NS Non-standard size
F44 24x101mm 70NS Non-standard size
G42 24x144mm 90NS Non-standard size
G55 24x177mm 125NS Non-standard size

Aerotech makes and sells reloadable motor casings and reloads in 18,
24 and 29 mm sizes. The 18mm is the size of an Estes C motor. The
24mm is the size of an Estes D or Aerotech E motor. The 29mm is the
size of an Aerotech G motor. Aerotech High Power, formerly ISP Consumer
Rocketry division, makes a 60NS F and 100NS G casing, both 29mm in
diameter.
----------------------------------------------------------
5.9 Can I use Aerotech or other composite motors in my Estes rockets?

Yes and no. They are the same size. Composite motors have 2 to 3 times
the power of comparably size BP motors. Balsa-finned 18mm powered models
tend to loose body parts in quantity when launched with a D21 or E25.
The ejection charges seem to be hotter, as well (IMHO). The same holds
true for Aerotech 24mm motors. Care should be taken before launching a
24mm-based model on an E15, let alone an E30. I have an old MegaSize that
I fly on E15-10's. Works great. The Estes Saturn V flies well on E15's,
too. E30's tend to shred all but the strongest D models, though. E30's
also tend to relocate motor mounts to someplace OUTSIDE of the rockets, as
well. If I plan to use E's in an Estes model I make it a point to
reinforce
the motor mount, especially for EM-2060, EM-2070 and EM-5080 mounts.
You also want
to use an engine block (a 2050 adapter ring works great) in addition to
the metal clip. IMO, I would also reinforce fin/body tube joints. Five
minute epoxy fillets work great. Generous cyano fillets also seem to work
well. White glued fins don't seem to survive E15/E30 launches with any
consistent success (i.e., the failure rate tends to be > 50% :-). Many
modelers also recommend that stronger 24mm motor tubing, such as that from
LOC or Aerotech, be used for models flying with composite motors. The
stronger tubing holds up better to the ejection charges of the composites.

There are now several D and E reloads available for the 18 and 24 mm
casings that might not over power 'standard' model rockets. The RMS
motors have a variety of reloads available, some with fairly low average
impulse.
----------------------------------------------------------
5.10 Will my Estes launch system work with Aerotech composite motors?

The classic Estes, Quest and MRC 6 volt launch systems will not reliably
ignite the Copperhead (TM) igniters that come with Aerotech motors, and
Estes Solar Igniters (TM) will not ignite a composite. These motors need
12 volt systems for reliable ignition.
----------------------------------------------------------
5.11 Can I use Aerotech composite motors as boosters in my multi-stage
rockets?

Basically, NO. Black powder booster motors will not ignite composite
motors. Therefore, you cannot use a composite upper stage in a traditional
multi-stage, black powder rocket. Also, there are no composite booster
motors currently in production. They all have delays (4 seconds being
the shortest current delay from Aerotech, for example) or are plugged.
Typically, you cannot (and should not) use these as boosters in standard
black-powder multi-staged rockets.

If you want to use composite motors in multi-stage models then you have to
use other methods of igniting the upper stage (whether black powder or
composite) than are used with black-powder-only rockets. One method is
to electronically ignite the upper stage motor using a mercury switch to
complete an electrical connection to a capacitor at first stage burn-out.
This, in turn, sets off a flash bulb/thermalite fuse combo which ignites
the upper stage motor. Another method is to ignite lengths of thermalite
fuse at the time the booster is ignited. The length of fuse determines
the delay before the upper stage is ignited. Refer to the 'Other Sources
of Information' section in Part 1 of the FAQ. The NCR High Power technical
reports on staging composite motors is applicable to multi-staged,
composite motor powered model rockets as well.

Bob Weisbe uploaded plans for a mercury switch-based staging system that he
used in a converted Estes Terrier-Sandhawk kit. The URL for these plans
is:

http://sunsite.unc.edu/pub/archives/rec.models.rockets/PLANS/terrier_sandhawk.ps

----------------------------------------------------------
5.12 How can I tell the age of my Estes motors?

Estes uses a date code on their rocket motors. It's of the form XXYZZ
(example, 25T9) where the first number is the day of the month of
manufacture, the letter is a code indicating year of manufacture, and the
last number is the month (1 = January, 12 = December). Date codes
run progressively through the alphabet, as follows:

T 1989
U 1990
V 1991
W 1992
X 1993
Y 1994
Z 1995
A 1996 - Estes cycled back to the beginning of the alphabet

In the early 70's, Estes motors had the actual date stamped on them.
----------------------------------------------------------
5.13 Are reloadable model rocket motors shippable the same as disposable
model rocket motors?

The Aerotech RMS line of model rocket reload kits (of B through G power
levels) has been certified by the DOT for shipment as Class C Flammable
Solids. This means that the reload kits may be shipped the same as
other model rocket motors, such as those made by Estes and Quest.

There are no shipping restrictions of any kind on the motor casings and
closures.
----------------------------------------------------------
5.14 My flying field is so small I keep losing my rockets. What can I do?

DON'T GET DISCOURAGED. Everyone loses rockets. It's part of the hobby.
There are ways to minimize this when you're forced to fly in smaller
fields, though. The following is a consolidation of tips posted to r.m.r
by numerous individuals:

Recovery Modifications:
1. For smaller rockets, use a streamer instead of a parachute. This
can be done with rockets of up to BT-50 body tube size and up to
18" long. Be sure and check rocket weight, though. If the model uses
heavy plastic fins you might still want to use a parachute.
2. Reef the chute lines to reduce the effective surface area. Tie or tape
the shroud lines together 1/3 of the way from their end. This reduces
the shroud lines to 2/3 of their original length and prevents the chute
from fully opening. The rocket will come down faster and drift less.
3. Cut out the Estes or Quest logo from the center of the chute. This lets
more air spill through the chute and reduces its drag. Be careful
to cut
out the whole logo. Cutting only a small whole (say, less than 2" in
diameter) can improve the chute's stability and actually make it lift
better and drift further.
4. Use a smaller chute. Try cutting down an 18" chute to a 15" chute, or a
12" chute to a 10" chute.
5. Use longer ejection delays. If a B6-4 ejects the parachute right at
apogee, use a B6-6 to let the rocket come down a little before popping
the chute. Less time chute is open equals less drift. Take care in
making the chutes and recovery attachments extra strong, though, as
the descending model will put more strain on the recovery system than
if it were to deploy at apogee.

Other Suggestions:
1. Find a different field. If you fly alone, try and find a local rocket
club. The odds are the club will have found a better field in which
to fly.
2. Fly larger rockets. A Big Bertha on a B6-2 will drift a lot less
than a Sky Hook or other small model on a B6-4 or B6-6. Larger models
have more impressive liftoffs, as well. Larger diameter rockets
don't fly as high and come down faster than the really small ones. The
big ones are also easier to spot in high grass, weeds, trees, etc.
3. Use smaller motors. If the recommended motors for a rocket are, for
example, A8-3, B6-4 and C6-5 or C6-7, try it on A8-3's first. If
the model lands well within the recovery area you can then decide if
the larger motors will allow the model to be retrieved.
4. Launch rockets at a slight angle into the wind. The rockets will
weathercock and deploy recovery systems upwind. If all goes well, they
will land closer to the launch site.
----------------------------------------------------------
5.15 Are Jetex engines still available? Where can I get them?

Although, technically, jetex type products are NOT model rocket motors and
do not fall under NAR/NFPA guidelines and safety codes, a number of
questions do pop up about these on r.m.r. The following sources have been
quoted on r.m.r as selling Jetex products:

Peck Polymers
P.O. Box 2498
La Mesa, CA 92041

Doylejet
P.O. Box 60311
Houston, Texas 77205
(713) 443-3409
----------------------------------------------------------
5.16 BT-20, BT-50, BT-55. What the heck do the numbers mean on Estes
body tubes? Is their any special meaning in these numbers?

From: Pete...@aol.com (Peter Alway)
Estes tube numbering seems to have progressed like the numbering
of steps in a BASIC program. The very first Estes Catalog had
numbers unlike the BT-20..BT-50... etc. system they use now.
Sometime in the early 60's they gave numbers 10, 20, 30, 40, 50
to their tubes in order of size. 10, 20, and 30 were almost
identical in diameter (though 10 could be coaxed to fit into
30) All were meant to hold 18 mm rocket engines. BT-10 was
an ultra-light spiral-wound mylar, BT-20 was essentially as it is
today, and BT-30 was a parallel wound heavy-duty tube. BT-40
was also a parallel wound heavy tube that fit over BT-20. (rather
like Quest T-20, but thicker and parallel wound.) BT-50 was as it
is today, as was BT-60. BT-5 came along later, I believe created
for the top of the Aerobee 300, and numbered halfway between 0 and 10.
BT-55 came along after BT-60 and was numbered to fit in. PST-65 egg
tubing came after the much larger BT-70 (originally used just for the
Sprite tail ring) BT-100 and BT-101 first appeared in the 1/70 scale
Saturn IB. BT-80 was created for the Saturn V. It is interesting to
note that two standard HPR diameters, 2.6" and 4" began as scale
model components. Estes also created BT-3 for the Saturn IB, and BT-51
for the tanks. BT-52 was produced for the BT-60 Semi-Scale Saturn V, and
this tube still appears as a hook-retaining sleeve on some Estes D engine
mounts. The sleeves are still correct for a 1/242 Saturn V. Many BT-5
clone kits still use the length for an Aerobee 300.
----------------------------------------------------------
5.17 I've seen mention of all kinds of rocket motor types and sizes. Could
you give a brief history and summary of the main marketing names for
model rocket motors?

From: msjo...@WichitaKS.NCR.COM (Mark Johnson)
The original hand-loaded motors made by Orville Carlisle and sent to
Harry
Stine in about 1956 were 0.5 in dia. (13mm) x 2.25 long (55 mm). These
were used in early testing up until the time Model Missiles Inc (Stine's
company) began to produce commercial product in sufficient quantities
that Carlisle could no longer make motors fast enough. These had total
impulse roughly from today's 1/2A to about the middle of the B range.

Stine contracted with Brown Fireworks Co. of Missouri in 1958 to make
mass-produced motors. Brown could have made them in the same size as the
Carlisle motors, but it would have meant costly new tooling. Mr. Brown
offered to produce a low-cost motor for MMI using his "Buzz Bomb" case
size - 0.7 x 2.75 in (18 x 70 mm) - the Buzz Bomb had a small aluminum
blade on one side of the case and a nozzle drilled into the side of the
case opposite, where a fuse was inserted. Strictly a fireworks piece.

In about 1959 or 1960, Vern Estes entered the picture, having offered to
produce motors for less than whatever price MMI was paying Brown. G.
Harry
took him up on the offer, and Vern began making motors in the
now-standard
18 x 70 mm size. He quickly automated production with the first of
several
"Mabel" machines and was able to make far more motors than MMI needed.
That's when Estes entered the model rocket business himself.

The short motors were 1/4A and 1/2A motors which came about in around
1963
or 64 when somebody at Estes realized that the upper 1" of the casing had
nothing in it, and was just dead weight. So Estes started producing the
"S" series, with a case size of 18 x 45 mm (0.7 x 1.75 in). These
continued in production until 1970 or so.

In about 1970 or 1971, Stine (whose MMI had gone out of business
somewhere
around 1962) reentered the hobby as a paid consultant to Model
Products Co.
(MPC), which later spun off its rocketry business as AVI (Aerospace
Vehicles Inc). Stine persuaded Mike Bergenske that there was a market for
the "classic" 13 x 55 rocket motors as a high-performance motor, in sizes
from 1/4A to B. These were the Mini-Jet motors, which quickly resulted in
rewriting the NAR altitude record books. Estes followed suit with its
mini- motor line, originally trademarked "Mini-Brutes" with the 13mm
diameter but choosing to go with a length compatible with the old "S"
series at 45 mm (so they could use the old "S" series engine hooks, I
presume). Centuri's "M" motor series, in sizes from 1/4A to B, were
released at about the same time. These were 13 x 50 mm (0.5 x 2 in)

The other "standard" motor type which emerged about this time was the
Estes "D" motor, which was sized to fit easily in the BT-50 or 25mm tube,
while keeping the 70 mm length constant (save the engine hook tooling
again, I guess). These first hit the marketplace about 1969; I still
have the original announcement flyer somewhere in all my old files. The
24 mm diameter has become the "small high power" standard for D, E, F,
and even a few G motors, mainly from AeroTech. Estes chose to keep the
existing standard diameter and extend the length on their new E15,
introduced during 1993.

The 29 mm standard motor emerged from the Enerjets. The original
Enerjet-8, a fiberglass-cased motor developed and produced by Rocket
Development Corp. of Indiana (RDC, later acquired by Centuri as
Enerjet, Inc) was an external-delay, 29 mm diameter motor with about 35
N-sec of total impulse (8 lb-sec). The Enerjet-8's external delay was
too cumbersome for unsophisticated users, and was replaced by a
conventional internal delay when the Enerjet E24, F52, and F67 were
introduced in 1973 by Enerjet and Centuri, its parent. The F67 was the
first full 80 N-sec F motor produced in the US.

FSI is a bit of a cipher in all this. They chose to go with a 21 x 70 mm
motor for A, B, C, and small D motors, beginning in about 1966 or so.
Their full D and small E motors are in 21 x 95 mm cases. (D18, D20, and
E5). The larger FSI motors are in 27mm cases of various lengths. The E60
is about 95 or 100 mm long, and the F7 and F100 are 125 mm. FSI started
producing 18 x 70 mm A, B, and C motors in about 1985 or so.
----------------------------------------------------------
5.18 Why don't I just make my own model rocket motors? Shouldn't I be able
to custom-make better, more powerful motors, at a cheaper price?

This subject has been hotly debated on r.m.r. It is one of those
'emotional' subjects that find people either firmly for or against.
The following post from Lawrence Smith probably says it all best.

From: thes...@mv.mv.com (Lawrence Smith)
In our pre-made, factory-produced society there is a bit of nostalgia
for doing things the "old-fashioned" way - "home made" carries with
it the feeling of being somehow "better". It could be tastier, more
durable, easier to maintain, or cheaper, it is some quality that we
don't find in mass-produced items. It is therefore natural for fans
of rocketry to look at the prices of the ingredients of an engine and
think to themselves that such engines really can't be all that difficult
to make - and that "home made" might be not only cheaper, but
just as good as factory engines in other ways.

There is a grain of truth here - _just_ a grain - but that is enough
to make the idea pretty dangerous. Most readers of this will not be
old enough to remember the "Basement Bomber" headlines from the late
fifties and early sixties. Making solid-fuel rocket engines _is_ a
pretty dangerous proceeding, unless you do it _right_. And even if
you do it _right_, you must be _consistant_ in following the safety
precautions. It really won't matter whether it is the first or the
fiftieth engine that blows your hand off in the long run. It is the
need to watch the safety precautions that is your first "hidden cost",
something that most people dreaming of home-made engines seldom add to
the calculation.

You need _room_, you can't do it in your basement, nor, indeed, in
your house at all. Nor in your apartment, nor in your school chem
lab, nor anywhere else there is something you don't want blown up.
You must _assume_ the engine _will_ blow up, and ask yourself where
it would be okay. Maybe an outbuilding on your property, maybe out
in some field. You need _space_ to build engines. You either need
to own that space or have the permission of people who do, too.

In most places in the country, you need some sort of _license_.
Rocket engines are first cousins to pipe bombs, and there are
few municipalities that would care to have you building those. On
the other hand, there are many municipalities that don't care if you
reload spent shotgun shells, even without a license. You need to
know and understand the local regulations. You are not building a
class "C" toy propellant device. Even if you _think_ you are. That
is a legal name, not a descriptive one.

You _can't_ reuse Estes or other maker engine casings. Spent casings
have undergone considerable stress, they can no longer be guaranteed
to hold if reloaded and fired again. Yes, they have a fairly consider-
able safety margin. It isn't enough to reload them.

You _can't_ use the same stuff Estes uses, nor can you easily obtain
composite fuel. Estes uses black powder - gunpowder - but they are
using a special formulation, not just mixing the usual ingredients.
In fact, it's pretty dumb to use any powder at all. Powder must be
rammed to make it solid enough for "solid fuel" - that means you have
to pour the powder into the casing and then take a stiff rod and ram
it up and down, like one of those old-time muskets. Ramming will
compress the powder - which is the objective - and will also heat it,
which will also make it more shock-sensitive, not to mention the heat
from the friction of the rod itself moving up and down in the casing.
It can also raise dust, which is also more easily ignited than a solid
slug. A fellow by the name of Jim Flis posted a commentary on creating
such engines, I recall. If anyone saved that post, I'd like to see to
see it inserted here.

Even if you manage to pull off all the above, the engine may not perform
like you expect. Your ingredients may not be up to snuff, or maybe you
didn't ram enough, or maybe something else got mixed in by mistake, or
maybe you forgot to add the final layer to the casing - whatever. There
is a real good chance any home-made engine is going to do serious damage
to your rocket, even if it didn't do any to you. One of the things you
pay for from Estes and Quest is _quality_control_. And even with
professionals
with years of experience with A, B, and C engines, Estes has
problems with D and E engines. Can you really do better?

Estes, Quest, and the others have _time_, they have _equipment_, they
have _space_, they have _quality_control_ and lastly, they have
_liability
insurance_ for when something happens with one of their engines. _That_
is what you are paying for, not just a couple teaspoons of black powder
and a bit of clay and cardboard. As you can see, there is more than
meets
the eye in an Estes or Quest engine. The fact of the matter is this: a
premade, off-the-shelf engine _is_ cheaper, more reliable, and far, far
less effort to obtain. There is really no reason to try to duplicate a
standard engine.

That said, there will remain a small core of people who still want to
roll their own. Maybe they need a non-standard size, or they just are
more interested in the engine than in the rocket. Before you proceed,
you will need a copy of "Rocket Manual for Amateurs" by Bertrand R.
Brinley, Capt. It's out of print, so you'll have to do some looking.
If you aren't patient enough to track down a copy then you aren't
patient enough to build engines. Take the hint.

Brinley gives a good overview of propellant technology up to the mid-
sixties or so, which is good enough for you, since the advances have
mostly been in the realm of "real" rockets with incredibly exotic
chemistry. He concludes that amateurs should stick to zinc and sulfur.
Zinc and sulfur can send rockets high enough to need an FAA waiver, so
this is really not limiting. Also, though zinc and sulfur can be ram-
med, they can also be mixed with acetone or alcohol to form a putty
that can be inserted into a casing and cast into shape. This he terms
"micrograin". I won't go into detail on proportions or other infor-
mation, you'll have to find the book. _I_ not telling you how to
build an engine, _I_ won't do it, and I don't think _you_ should, but
if you are anyway I want you to be aware of what you need to do to
succeed, for if you fail the consequences will be horrible.

While Brinley is helpful for fuel, he is more valuable for the kinds
of safety precautions you need to take. You are going to need sand-
bags. Take the hint.

One thing Brinley assumes, though, is using metal cases, including CO2
cases for small engines. This will _definitely_ make your rocket require
an FAA waiver, and the metal content will make it easy to spot your
rocket on radar, so you better not try to mickey-mouse it. Of course,
the FAA will _not_ be forthcoming with a waiver for an experimental
free-flight rocket, unless you are launching from someplace in the
southwest desert area, and maybe not even then. In a way, this is an
advantage. A metal-encased engine will fragment when it explodes, and
is far more dangerous that one in fiberglass or carbon fiber. Also,
metal is far more likely to cause a spark somehow than are non-metallic
components, and so are safer to handle. This limits the size and
materials you can use.

You will need to improvise on Brinley and develop a fiberglass or
carbon-fiber casing and clay or other material nozzle. I have an
ulterior motive for mentioning this, and I admit it freely. Making
a casing like that is not trivial to begin with, and you will find
it's pretty expensive, both monetarily and in terms of time. If
that still does not deter, at least you will be encouraged to make
your engines _small_ - which will make the process safer, for there
will be less to explode. I have no idea how thick the casing needs
to be, nor would I say if I did. Again, you need to do your home-
work.

If you take the advice in this post to heart, you will not make a
rocket engine. If you take only some of it, you will build a much
smaller engine, in a casing less likely to become deadly shrapnel
(not _un_likely, just _less_ likely), and with techniques less likely
to cause an explosion. You will be doing it with the advice of a
professional (Capt. Brinley, not me) and hopefully will succeed, and
then either give it up or go legit and start a career with Morton
Thiokol. Who are, of course, the makers of the shuttle SRB's used on the
last flight of the Challenger, just in case you thought being a
professional meant that you had everything figured out.

Wolfram v.Kiparski

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Sep 26, 2000, 3:00:00 AM9/26/00
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Archive-name: model-rockets/construction
Rec-models-rockets-archive-name: rockets-faq/part06
Posting-Frequency: monthly
Last-modified: 1997 January 6
URL: http://dtm-corp.com/~sven/rockets/rmrfaq.toc.html


Rec.Models.Rockets Frequently Asked Questions: PART 06 OF 14

MODEL ROCKET CONSTRUCTION AND FINISHING

This section includes tips and suggestions on various topics having to do
with construction and finishing techniques. These have been posted to
r.m.r or mailed to the moderator by way of r.m.r request. Refer to the
High Power Construction section for additional tips, oriented towards high
power and advanced rocketry requirements. Even more construction tips can
be found in the Scale Modeling section.
[Note: This part of the FAQ is maintained by Robert C. Santore
(san...@ibm.net)
Any additions or corrections should be sent to that address]

-----------------------------------------------------
6.1 Cutting, Sealing, Attaching Fins

From: JC...@Epoch.COM (Jim Cook)
Skip using glue W/ balsa dust, dope, or any other junk for filling the
grain in balsa fins or nose cones. Use Elmer's "Fill 'n Finish" diluted
with water to a thick paint (like white glue is) and paint it on.
Non-toxic and a coat or two will do. Use Elmer's "Carpenter's Wood
Filler" thinned similarly to fill the spiral in body tube. Both come
in a white plastic tub with an orange lid. Note - the latter is
harder to sand, so don't make the mistake of using it on balsa as it
will require a lot of sanding.

From: c...@pdp.sw.stratus.com (C. D. Tavares)
Fill your fins BEFORE attaching them. (Don't fill the root edge).

From: utid...@remarque.berkeley.edu (David M.V. Utidjian)
[To hold fins in place and aligned while drying I bought an Estes
fin alignment kit]. At 15-16 bucks it seems a bit
expensive but is well worth the aggravation and time it saves. You
can even make your own if you are handy. I just set up my body tube
in the jig and then check the alignment of all of the fins to the body
tube. Then I use a thin bead of 5-min. epoxy. and in ten minutes I am
done. When I do the fillets I can do them all at once but don't have
to worry about the softening the glued on fins so they droop. You
still have to lay the model on its side though but only for 5 minutes.

From: kapl...@hccompare.com (Bob Kaplow)
The Estes Fin Alignment Kit has now been discontinued for '96. You can
use the newer Rocket Builder's Marking Guide ($5-8) to do one fin at
a time. [Editor's note: This is a HIGHLY RECOMMENDED item to purchase.
It provides everything needed to mark BT-5 through BT-60 body tubes
for 2, 3, 4, 6, or 8 fins.]
-----------------------------------------------------
6.2 Body Tubes (Cutting, Joining, Filling)

From: c...@pdp.sw.stratus.com (C. D. Tavares)
[On cutting Estes-style body tubes]
The simplest and best I ever used was Howard Kuhn's jig from the old CMR.
It's a simple piece of wood L-angle molding, with a notch for a razor
blade cut into one side (from the wing toward the elbow) at one end.
The only other parts are a wood block and a large black spring clip (the
kind you hold really thick reports together with). If you want, say, a
6" piece of tubing, you set the block 6" away from the razor notch and
clamp it there with the spring clip. Now lay the tube down the L-angle,
butting it up against the wood block. Insert the razor blade, press
lightly, and turn the tube. (Put a dead engine into it if the tube is
the right size to fit one.) Three to six turns, and you have an edge
that looks factory-cut.

----
( ) <- spring clip | <- razor (edge on,
/ \ | sharp edge down)
____________---------___________________________|_______
| /_| |__/| | |
| | |_______| || angle molding | |
| | wood block || |
|----------|____________|/-------------------------------j
/ lay tube here and spin it /
/________________________________________________________/

From: soc...@vx.acs.umn.edu (Tim Harincar)
[On cutting Estes-style body tubes]
When I cut tubes, I always wrap the tube with about two
layers of drafting tape with the edge of the tape along
the cut line. This accomplishes two things: First the
thick tape edge providing a excellent knife guide. Second,
you can assure a straight cut. If the tape wrinkles when
you wrap the tube, you know it is not on straight; simply
remove the tape and try again until you know its down flat.

Drafting tape is better than regular masking tape because it
has almost the same thickness but is made to be removed.

This method is in addition to reinforcing the inside with
a stage coupler or spent motor. Also, always use a new
x-acto blade for the best cut.

From: Jim Bandy (NAR member not on net)
Use a piece of aluminum 'angle iron' for joining body tubes. Place one
tube in the angle, insert and glue the joiner, then insert and glue the
other tube. It give very straight joins. The angle can also be used
for marking fin lines on body tubes, etc.
-----------------------------------------------------
6.3 I'm fed up with tangled plastic parachutes with broken shroud lines. How
can I improve on the standard chutes, or make my own?

From: soc...@vx.acs.umn.edu (Tim Harincar)
Making your own parachutes is pretty easy. Start with the desired
material (usually mylar or a light plastic). Make a cutting pattern out
of cardboard by first drawing a circle that will be the maximum size
of the chute (i.e. 16"). Take a compass [or] something that will give
you an accurate radius of the circle. Pick a point anywhere on the
circle and using the radius as a length draw an arc that crosses the
circle. At the point where the arc crosses, reposition the compass on
that point and draw another arc. Keep doing that all the way around
the circle - you will end up with six points including the starting
point on the circle. Connect these points with a straight edge and
Presto! a hexagon. Cut out the hex from the cardboard (I use artists
matte board...) and this is your cutting template. Lay the template on
the material and using an EXTREMELY SHARP XACTO KNIFE cut along the
outside of the template. Make shrouds from a heavy gauge thread -
cut three equal lengths twice as long as the diameter of the chute and
connect the ends to corner points adjacent to each other.

From: Roger....@umich.edu
I usually build 12-24 line round chutes out of Estes material (just cut
around the outside of the red and white circle and attach at the red
/white boundaries) because they look more like real parachutes. I use
embroidery floss for shroud lines and separate the 6 strands (for 12
lines - use two lengths for a 24 line). This makes a strong chute.
With out crossing the lines over the top of the canopy, I've only had
one failure of a 12 line chute (an EL that tipped off dramatically -
i.e. cruise missile) and never had a 24 line fail. In the 10 years
I've been back in the hobby and using this technique, my shroud lines
have always come out the same length (within a couple of percent
tolerance).

From: h...@HQ.Ileaf.COM (Hal Wadleigh)
1. Use fisherman's snap swivels for your attachments. It lets you
store 'chutes separate from rockets and helps prevent fouling due
to spin at deployment.[Note...modelers have always reported mixed
results with snap swivels; they have been known to fail...Buzz]
2. Use nylon coat thread for shroud lines on homemade 'chutes (and
plastic bread wrappers are the best cheap 'chute material).
3. Pay special attention to the security of the attachment points.
Those standard stickers often look secure, but are actually not
attached. A small knot in the part of the shroud line under the
sticker serves as a good anchor point (with the rest of that part
looped around the knot, as per standard practice).
4. Very small 'chutes should be cross-form type. Cut about a 5" square,
then take out about 1.25" squares from each corner. Attach 4 lobes
of shroud across the flat ends and secure as above. Be careful to
use small stickers for the corner attachments. These make good
substitutes for streamers in .5" body tubes and can also be used as
drogues to help in the deployment of large 'chutes [A note from
c...@sw.stratus.com (C. D. Tavares): Either round off the inside
corner of that 1.25" square or reinforce the angle with something.
Otherwise, it's a really handy place for the parachute to rip
during a fast deployment.]

From: sm...@mrcnext.cso.uiuc.edu (Greg Smith)
Nylon coat thread is very good for small, lightweight competition
parachutes, but it's not real strong and does have a tendency to melt if
it encounters a bit too much ejection charge heat. For sport and
payload models with 12" - 24" plastic 'chutes, I use 15 lb. *braided*
nylon fishing line. It's thicker than the coat thread, similar in
diameter to the Estes cotton stuff, but tremendously stronger. In the
last fifteen years, of the plastic parachutes I have built using this
line (and always crossed over the top of the 'chute for reinforcement),
I have had *zero* shroud line or attachment failures. The braided line
has a hard, smooth surface that doesn't encourage tangling, and it
doesn't unravel where cut.

From: whi...@nssdca.gsfc.nasa.gov (Rusty Whitman)
I've tried about everything to keep shroud lines from pulling off of
plastic or mylar parachutes. Those little tape disks are just about
worthless. Tying knots and cyano'ing the ends helps but you still
have problems. I don't know why I never thought of this before but I
ran across a roll of duct tape in my closet and knew immediately that
was the answer. I cut out some little squares of duct tape and
attached some lines to a parachute and they won't pull free without
ripping the plastic. I don't know who invented duct tape but they
deserve some kind of statue, its got more uses than a paper clip.

From: kapl...@hccompare.com (Bob Kaplow)
1. Make shroudlines from Kevlar thread. This won't burn through. Tie
a knot 1/2" from the end and fray the end. Attach that end to
parachute.
2. Use the much stronger kite snap swivels instead of fishing swivels -
make sure they lock, and don't just clip like a safety pin.

-----------------------------------------------------
6.4 Alternatives to Recovery Wadding

From ja...@rml.com (Jack Hagerty):
Just go down to your local building supply store and get a bale of
cellulose wall insulation. This is just shredded newspaper treated in
the same fire suppressant [as Estes recovery wadding]. A $5 bag will give
you enough wadding to last years!

From MAS...@TRAVIS.llnl.gov (Warren Massey):
I have found crepe paper to be a must more cost effective alternative.
It comes in either sheets or rolls (I prefer the sheets) in a variety of
colors and is every bit as flame retardant at a fraction of the price. I
can even get several flights off a single ball of wadding. It is somewhat
stiffer than the tissue but I've never found that to be a drawback.

Unattributed:
A piston ejection system works well on rockets of BT-60 size or greater.
Pistons eliminate the need for recovery wadding of any type. Plans
for a D powered rocket using piston ejection may be found on sunsite.unc.
edu in the file 'pub/archives/rec.models.rockets/PLANS/dust-devil.ps'.
The rocket was designed and drawn by pfei...@nmsu.edu (Joe Pfeiffer).

From: kapl...@hccompare.com (Bob Kaplow)
Use a baffle system (I posted this to RMR a while back) to eliminate
the need for wadding. This also provides the benefit of a third centering
ring (see Pete Olivola article) as part of the baffle system. Stainless
steel mesh can be used to trap hot particles, but be careful that
ejection
caps don't plug it up.
-----------------------------------------------------
6.5 Are there any good tips when making my own nose cones?

From Chris Jennison
To keep nose cones from wobbling and coming out asymmetrical when using
an electric hand drill as a lathe...
Use a blank (dowel, broom stick or balsa block) 1/8 inch larger
(diameter) than the nose cone that you need. Drill a 1/4 in. diameter
hole
as close to dead center as you can and push in a 1/4 in dowel. Dowel
length should allow the nose cone end to seat against the face of the
drill chuck. Find dead center by running the drill clamped in a vise at
moderate speed & slowly move a soft pencil toward the end at what
appears to be the center of rotation. After a couple of tries you will
find the center because your misses will draw concentric circles like
a bullseye. Now remove the dowel from the drill, clamp the shoulder end
in the vise and rough shape the nose cone with a file or rasp using the
marked center as a guide. Final contouring and finishing is done in the
drill with progressively finer sand paper.

-----------------------------------------------------
6.6 Getting Paint to Stick to LOC and Aerotech Nose Cones

From: kwo...@interramp.com (Ken Wolfe)
VERY VERY important......WASH THE PLASTIC FIRST!
I had this problem until I started to wash the plastic before even
assembling anything. This solved most of the problems I was having.

From: Roger....@umich.edu (Roger Wilfong)
I have had success painting nose cones from both companies using Krylon
and Walmart paints. The technique I use is to wash the nose cone with
a Brillo pad followed by a thorough rinse. Fill the mold parting mark
with auto body putty and sand it smooth. I next use a coat of primer
(I've used Krylon's gray sandable, Walmart's gray and Black Baron - the
Black Baron was the best, but also the most expensive and took the
longest to cure). This is followed by a light sanding and another
coat of primer, followed by sanding. After the primer cures (a week, if
I'm in the mood to paint, a year if I'm not), paint it with some paint
that's compatible with the primer.

This technique works fine on the LOC nose cones, the only problem I've
had with the Aerotech nose cones is that the very tip tends to get
chipped off.

I have a LOC PNC-3.00 that has lawn darted into hard ground twice. The
original paint is scratched, but it shows no signs of flaking off.

From: sm...@mrcnext.cso.uiuc.edu (Greg Smith)
I rough up the surface of plastic nose cones with 60 grit paper, then
use my basic epoxy painting regimen as I've described earlier. After
the first coat of primer, the surface is *really* fuzzy; the paint
reinforces and thickens all the little plastic strands that are raised
by the sandpaper, and the surface feels like rough concrete. But a
little sanding knocks off most of it, and after the third primer coat or
so, the surface is as smooth as anything else on the model.

The only time I've ever damaged the finish on one of these nose cones
happened when a model fell off the workbench and onto the concrete floor
in my basement, which chipped the tip of the cone a bit. Normal flying
(including one or two landings on concrete) hasn't affected them at all.

From: js...@rc.rit.edu (J A Stephen Viggiano)
As I have said repeatedly, the most effective way to paint on these
plastics is to introduce carboxyl groups at their surfaces. This will
give the paints something onto which they can grab.

A carboxyl group, also known as a fatty acid group, consists of a
carbon atom, to which an atom of oxygen is doubly bonded, and also
a hydroxyl group is bonded. In order to convert the end of a polymer
chain into a carboxyl group, you need to provide oxygen and some
energy. The oxygen may, of course, come from the atmosphere.

In the packaging industry, when polypropylene and polyethylene must be
printed, they are given either a "corona discharge treatment," in which
the surface is passed beneath a high-potential device called a coratron,
or a "flame treatment," in which a gas flame is allowed to impinge
on the surface for an instant. For historic reasons, the second treatment
may be referred to as a "corona treatment," even though no corona
discharge is involved.

I've used the gas flame from my kitchen range with excellent results.
Don't overdo it, for obvious reasons. Only an instantaneous contact
with the flame is needed.

Since using this treatment, I have had virtually no problems with paint
flaking from my polypropylene nose cones.

From: M Preddy <pre...@ucs.orst.edu>
I've had good luck with Rustoleum primer on LOC nose cones. Krylon
sticks to it fine.

From: kapl...@hccompare.com (Bob Kaplow)
Consider covering nose cones with econo-kote.

-----------------------------------------------------
6.7 Is it possible to get a high gloss, durable finish on a model rocket?

From: p_ham...@usa.pipeline.com (Paul Hamilton)
I put on a clear coat of dope or Krylon, sand with #600 wet-or-dry
sandpaper, and then buff with "Rotten Stone" or similar rubbing compound.
This is a fine abrasive that on mixes with water. I have used toothpaste
or silver polish as a substitute for rubbing compound when there has been
no hardware store around.
-----------------------------------------------------
6.8 Are there any good paints for silver details on scale models?

From: Orville ????
The Krylon silver paint looks very much like real silver, that's
because it's made of a clear coat plus real metal flakes.
The only problem is when you touch it the finish becomes dull.

The solution to this problem is:
Finish your surface as usually.
Spray a final coat of Krylon on and let dry 2 days, but don't
even think about touching it. After 2 days spray Krylon clear coat
over the silver with very light coats ,letting each coat dry 5 minutes
between sprayings. This will give you a very nice finish.

From: Peter "wondered if they had silver spray paint for the Tin Woodman's
axe in the Wizard of Oz" Alway (al...@pooh.physics.lsa.umich.edu)
I'm starting to get serious about silver paints, now that I am working
on 1930's rockets. I think it's worth getting a sense of several
metallic colors, all for different purposes. As near as I can tell,
most are either simply glossy (Testors Chrome, Dutch Boy silver) or
matte (Testors silver, and apparently Krylon.

As an experiment, I tried buffing some Testors siver on a nose cone
(it was still chucked up on the drill press wher I turned it) last
weekend. I found I needed to use dome #600 sandpaper to get a truly
smooth surface, then I just buffed it with ordinary paper. The result
was pretty convincing, but a darker shade than the original
paint. (unfortunately, on Goddard's rockets, the nose was usually
a lighter shade of Aluminum) I was impressed that the result looked
like real metal to me.

Testors has some buffable paints in their Metalizer line. I tried their
"Titanium" on a Glencoe 3-stage rocket ship (a von Braun design), but
when polished, I thought it looked more like hematite than actual
metal. I'm starting to believe that with silver paint, it's more
important that you represent the differences between silver shades
than get the siver just right. So for instance, on a Goddard
rocket, I would use the glossy Dutch Boy silver for the nose cone,
buffed silver paint for the nickel-steel propellant tanks, and
testors silver for the duralumin body. This should at least
suggest the differences between the materials that you can see
in the photos.

From: Bob Craddock (crad...@aol.com)
After building and re-building about a half-dozen Saturn V's, I have a
couple of recommendations to make:
For the Service Module color, I suggest getting a bottle of Micro Metal
Foil Adhesive and some Reynold's Wrap. Spread the adhesive on the
**shiny** side of the foil. The silver on the SM was somewhat dull, and
just about ANY silver paint sucks badly! The foil will give you the
look
you need, and the adhesive is extremely easy to work with. The white
raditor details can be added by using shroud line or Evergreen styrene
strips. White glue works well with the shroud line, but I would
recommend
fast epoxy for the strips. Mask of the radiator areas so you can paint
them white when you paint the entire rocket.
-----------------------------------------------------
6.9 How can I prevent a rocket painted white from yellowing?

From: cur...@telerama.lm.com (LarryC)
Future floor polish (it isn't wax) doesn't yellow. I find it useful for
rockets but...

1) It must be used over some kind of paint or over acrylic gesso. If it
seeps into cardboard or wood, the material will become brittle;

2) It will cause dope and (even permanent) Magic Marker color to run.
This effect can be used to advantage, but it can also ruin a model if
it's unexpected. Future does not cause enamel paint to run, and may
certainly be used to cover decals. Don't know if the decal will yellow
beneath the coating.

3) A glossy finish is not always desirable, and Future yields only a
glossy finish. Art stores sell equivalent mixtures that come in gloss
or matte finishes. The are called "Acrylic Gloss Medium," and "Acrylic
Matte Medium," respectiely. They are thicker than Future, but they can
be thinned with water.

4) Acrylic colors, available in art stores, can be used on rockets, as
long as acrylic gesso is laid down first. The colors should be thinned
with water or Future. Acrylic paints are normally labeled to tell you
how opaque they are and how toxic they are. Both qualities vary from
color to color. Even though the tubes seem expensive, the opaque colors
have excellent covering power and they turn out to be very good buys.

5) From my own experience, commercial acrylic model paints are to be
avoided. They are over-thinned, and they yeild undesirable, cracked
finishes.

From: kapl...@eisner.decus.org (Bob Kaplow)
Try adding a small amount of BLUE to the white paint (a few drops per
bottle). The faint blue tint hides the yellowing, much like bluing in
the white laundry.

-----------------------------------------------------
6.10 Which is better, white or yellow glue? Epoxy? Cyano?

From: buz...@netcom.com (Buzz McDermott)
Yellow wood glue, such as Elmers Carpenter's Glue or Titebond, is far
superior to regular Elmer's white glue for building wood and paper model
rockets. Built carefully, with proper fin fillets, yellow aliphatic resin
will hold together on rockets with up to G power. Yellow glue also dries
faster.

Three and five minute epoxy is often used for quick repairs. This quick
drying time does not allow the epoxy to soak into the wood and/or paper
very well, though. If epoxy is to be used, then use one with at least
a 15 minute, and preferably a 30 minute, listed 'drying' time. Thirty
minute epoxy will give a much stronger bond than yellow glue. However,
5 minute epoxy often yields a weaker bond than yellow glue.

Cyano is often used for quick building. It bonds strong, dries extremely
fast (especially when using an accelerator), and is relatively easy to
use. Regular cyano can also be used to bond plastic to wood or paper.

No matter which glue is used, the most important factor is to have a
properly prepared surface. Glassine coated Estes-stype body tubes should
be lightly sanded where the glue is to be applied. All bonding surfaces
should be clean and unpainted. You want whatever bonding agent is used to
be able to soak into the paper and/or wood.

From: kin...@sisko.dnaco.net (kingrat)
I've been using CA to bond fins to the tube and then a fillet of
epoxy. If you go this route I recommend thin CA and a fin alignment
guide. Make sure the fins are aligned properly before you CA and check
again before applying the epoxy. Unlike white glue, if you mess up it's
REALLY hard to fix. It's also REALLY hard to pop the fin off too. :)

This works just fine with balsa or plywood fins from what I've seen. CA
is good for tacking the lugs in place too, however I would never use CA
on a vital part of the rocket (ie. motor mount) CA just isn't strong
enough because it turns brittle. Epoxy will flex somewhat without
breaking
and you can add microballoons to allow it to flex even more. In
short, use
CA to tack and epoxy to bond.

From: san...@ibm.net (Bob Santore)
There is an easy test to tell if the glue you are using is strong enough.
A glue joint only needs to be as strong or stronger than the material it
is gluing together. To test for glue strength you need to test the
strength of the glue joint relative to the strength of the material you
are bonding. This test is very easy and can be used for any type of
glue.
Glue some scrap pieces of whatever you are gluing together in a
configuration similar to how you intend to use it (i.e., don't test a
surface mounted fin if you intend to use a TTW fin). When cured,
pull the
two parts apart. Did the glue bond fail? If it did, don't use that
brand
of glue. If the pieces you glued didn't fail, then this glue is fine.
If your rocket falls apart anyway, then you need stronger rocket parts!
The only exception I can see to this very simple test would be near the
motor mount where heat can weaken the glue. You could always heat the
pieces before destructive testing to see if heat changes the
properties of
the glue joint.
-----------------------------------------------------
6.11 Improving on the Estes Shock Cord Mount

There are a number of ways to improve on the old paper-and-rubber-band
shock cord mount used by Estes for the past 35 or so years. The
following suggestions have been repeatedly made in r.m.r.

1. Replace the rubber band or short elastic in the kit with sewing elastic
at least twice the length of the model. This will help to avoid
tube zippering or ripped out shock cord mounts when you have a 'hard'
ejection.

2. Epoxy the shock cord mount to the inside of the body tube rather than
using white or yellow glue. Thirty minute epoxy works best for this.
Be sure and lightly sand the inside of the tube where the shock cord
mount is to be placed. Also be sure and 'cover' the entire mount with a
very thin layer of epoxy. This method works best for models with BT-60
or larger body tubes.

3. Use a 'Quest-style' kevlar-and-elastic shock cord mount. This type
of mount uses a length of 50 to 150 pound test Kevlar (such as Stren
Kevlar fishing line or Kevlar kite string). The Kevlar is tied and
glued to the motor mount (motor block, centering ring, or around the
motor tube). It is sized to end just shy of the front end of the
body tube when a length of elastic shock cord is tied onto the free
end of the Kevlar. This method eliminates any shock cord mount on the
inside surface of the body tube. Estes-style shock cord mounts have
been known to interfere with parachute deployment. You can used this
method on any sized rocket. Size the Kevlar appropriately.

4. You can also use a 'LOC-style' shock mount for body tubes in the
1.5" and up range. With this you take a short length of Kevlar line,
fold it in half, and make a !-2" loop in the closed end of the folded
line. You then epoxy the loop to the inside of the body tube in such
a manner as to have the end of the loop extend a little past the open
end of the body tube. A shock cord is tied to the loop. The advantage
of this technique is that is allows damaged shock cords to be easily
replaced. It tends to work better on body tubes greater than 1.5"
in diameter.
-----------------------------------------------------
6.12 I've built several BT-80 based models. How can I strengthen future
models to take larger motors, such as Aerotech 24mm or 29mm reloads?

Estes recommends using just D motors in their BT-80 based kits, such as
the Broadsword (Super Big Bertha) and Shadow (Optima). There are a number
of steps that posters to r.m.r have done to strengthen these rockets to
fly with larger motors. Remember in doing this that you are modifying and
using the rocket kit in a manner NOT recommended by the manufacturer.

From: Buzz McDermott (buz...@netcom.com)
Here's a summary of what I've done to strengthen my Shadow and Broadsword
kits to fly on 24mm reloads and up to 24mm G42 motors. You will need
a LOC-style 2.56 inch tube coupler, 3/4 oz fiberglass, 15-30 minute
epoxy, and 20 minute 'coating' or 'finishing' epoxy:
1. If the kit comes with the 'plain' BT-50 type motor tube, replace
that with LOC-type, thick-walled 24mm motor tube. You will only
need about 6".
2. Reinforce each body tube section with 3/4 oz fiberglass. Apply it
using
one of the methods discussed in the section on High Power Construction
Techniques. Be sure to completely sand off the glassine coating of
the
body tubes prior to applying the fiberglass.
3. Also fiberglass-reinforce the thick paper centering rings supplied
with the kit. Glass both sides of the rings. If you want to build a
payload section in the Shadow, then leave the center cut-out in one
of the rings and glass over it.
4. If you plan to use only 24x70 disposable motors (including Aerotech
E's) and/or 24mm reloads, then yellow glue or epoxy a motor block
2.5" into one end of the 6" motor tube. If you install the motor hook,
file down the part that sticks into the tube. This will let you
fit in 24mm reloads. Be sure and lightly sand the motor tube prior
to installing motor hook. [NOTE: If you plan to use non-standard 24mm
Aerotech motors than skip this step.]
5. Epoxy one fiberglass-and-epoxy-reinforced centering ring 1/2" from the
rear end of the motor tube. Be sure there is a notch in the ring to
allow some movement of the motor hook. Epoxy a second centering ring
in the middle of the motor tube. Epoxy a third ring 1/8" from the
front of the motor tube. Install the motor tube into the main
body tube with the motor tube flush with the bottom of the main body
tube.
6. Fiberglass-reinforce all of the fins. Apply the glass to both sides
of the fins. Be sure that the fins are completely sanded (and any
airfoiling/rounding completed) before applying the cloth. An optional
step is to apply some 1/2" wide strips of glass along all of the
fin edges EXCEPT the root edge.
7. Rough up the epoxy on the main body tube along the lines where the
fins will attach. Use 220 or coarser sandpaper. You really want the
smooth epoxy coating roughed up. You can also drill a few 'rivet'
holes along the fin attachment lines.
8. Apply epoxy where the fins will attach and attach the fins. Do not
fillet at this time.
9. When the fins are dry, apply 1/2" strips of fiberglass cloth along
each fin root edge, with 1/4" on the body tube and the other half of
the width along the fin side. Coat this will coating epoxy. When
dry, YOUR FINS WILL NOT COME OFF.
10. Couple the bottom two body tube sections together. An option step
is to make a payload section out of the third body tube section that
comes with the Shadow. Use the LOC coupler to make a payload section.
You can sand down the solid centering ring to slide inside the LOC
coupler to form a bulk-head. Epoxy a 2"x 2" piece of scrap 1/16"
plywood or 1/8" balsa to the inside surface of the bulkhead to add
strength. Install either a large screw-eye or small eye-bolt to the
center of the bulkhead, to be used to shock cord and parachute
attachment.
The end result of the above is a model which is really too heavy to
fly on a D12. My modified Shadow came out to about 14 oz (I built it
VERY heavy and added the payload section). My modified Broadsword came
out to about 12 oz. Both have been flown on motors as small as composite
D's (D21-4, D13-4R). The Shadow has flown on E15-4 (perfect), E30-4
(a -5 is really needed), F24-7R, F39-7R, and G42-8. The Broadsword
has just been test-flown on the D21-4 and E15-4. It WILL be flown on
G42's, though.

If you want to use 29mm motors in BT-80 based models, I would recommend
either switching to plywood centering rings or sticking to low-thrust
motors, such as the F14. In the end, if you want to fly 29mm, you would
really be better off getting a kit designed as a Large Model Rocket from
the start.
---------------------------------------
6.13 How can I prevent balsa fins from breaking off on landing (especially
for models with swept fins)?

From: Bob Craddock (crad...@aol.com)
Take your fin pattern, reduce it by ~90% on a xerox machine, and make
as many copies as you need to glue one pattern on both sides of each
fin. Put about two coats of sanding sealer on the new paper surface,
sand, and then paint the fins all over again. A friend of mine was
having the exact same trouble on his Super Big Bertha, and the paper
reinforcement was his solution. It worked great, but next time I
say use
bass wood on everything.

From: The Silent Observer (sil...@ix.netcom.com)
There's a variation on this technique, that needs to be applied during
building, that can make balsa fins stronger than bass (and still
lighter).
What you need to do is simply to cover the fins before painting.
I used silk tissue (like model airplane tissue made from silk
fibers) on my
Big Bertha, and in a dozen flights (before it lodged high in a tree)
never
had so much as a crack, even when flown on a D21 (and including one
"plastic wad" recovery when the rocket hit the ground fairly hard).
You
could use ordinary Japanese tissue, or Silkspan (R), or you could
even use
something like nylon cloth or very light fiberglass (attached with
epoxy or
CA in this case).
With tissue, you need to cover the entire surface -- I simply
wrapped it
over the rounded leading edge, and trimmed it off at the tapered
trailing
edge, leaving the square "bottom" edge and the root uncovered. You can
attach Silkspan with almost any glue, but silk tissue (as I found)
"fuzzes"
if you get it damp and handle it, so something like Testor's model
airplane
glue or thick, clear nitrate dope might be a better choice; it won't
soften
the binder that holds the fibers in the tissue together.
Any of these, done after sanding (and filling, in the tissue cases)
will add
significantly to the strength of the fin, while adding very little
weight.
Making fins out of basswood or ply is probably okay with a Bertha
derivative
-- they tend to be overstable in any case -- but may lead to an
unstable
model if you have a design with less margin.

From: David Bucher (dbu...@mcn.org)
There are two things you can do, both of which lower the rocket
in a "fin up" attitude. The first works by making a "yoke" or
harness for
lowering the rocket body horizontally ( if you choose). Install an
anchor
(screw eye, inch worm shaped brass wire clip etc.) through the body
tube
wall between the fins at the rear end of the body. Attach a squid
line or
kevlar thread to the anchor and run it up the outside of the body
(tightly)
and attach to the nose cone or 'chute. Configure it to lower rocket as
above.
The other (and better!) way for the rocket you describe is to use rear
ejection. This will not help you with the present rocket, but any other
rocket with sufficient body width will work just fine. When making the
motor mount assembly. substitute a longer motor tube (29mm LOC
tube for instance) and make up some ply or G10 centering rings
including
two with a fair spread between where you can wrap the 'chute around
the motor tube. Install a solid bulkhead with cable lanyard to serve
as a thrust ring and pressure block. Make sure the motor mount unit
slides well in the body and attach elastic to the cable lanyard and now
you've got a rocket that ejects to the rear. Just cut a small notch
in the
farthest forward centering rings to allow the shock cord to pass.
This me-
thod works great and if you're confused by what I just wrote (a not un-
heard of possibility!) just think of the internal "power pod" in some
BGs. It works the same way except you must make provision to conn-
ect ALL parts together. There are two things you can do, both of which
lower the rocket in a "fin up" attitude. The first works by making a
"yoke" or harness for lowering the rocket body horizontally ( if you
choose). Install an anchor (screw eye, inch worm shaped brass wire
clip
etc.) through the body tube wall between the fins at the rear end of
the
body. Attach a squid line or kevlar thread to the anchor and run it up
the outside of the body (tightly) and attach to the nose cone or
'chute.
Configure it to lower rocket as above.
---------------------------------------
6.14 I just lost my favorite rocket and the kit is discontinued. How can I
make another one just like it?

From: <sil...@ix.netcom.com> and <bmcd...@ix.netcom.com>
I don't know if everyone else already does this, but I've started
saving the
kit card, instructions, and a copy of the fin shape or shapes for
every kit
I build -- rockets have a way of getting lost or broken, and model
rocket
companies have a way of discontinuing my favorite kits. Getting a
color copy
of the decal sheet (or better yet, a color scan) is also a good idea.
---------------------------------------
6.15 How can I reduce damage to the booster stage of two stage models caused
by the engine exhaust of the second stage?

From: phu...@numill.com (Perry Hunter)
Try scotch tape instead of masking tape. It should release fractionally
faster and >might< reduce scorching of the lower stage.

In some cases, it's possible to line the inside of the top of the lower
stage with 20lb xerox paper, and it will take the damage rather than
the exposed section of the stage. It's not possible to cover everything
(slip fit couplers , etc. prevent lining all of it) but it can help.
---------------------------------------
6.16 Is there a way to increase the stability of a model with near
neutral stability?

From: Peter "My views are not to be confused with those
of a rabbit librarian" Alway (al...@pooh.physics.lsa.umich.edu)

Sounding rockets that are aerodynamically stable are often spun at a
slower rate that insures that any off-axis thrust will cause the
rocket to corkscrew, rather than follow an arc. The corkscrew may
be subtle--but it beats an equally subtle arc. A sounding rocket
that naturally describes an arc with a 20-mile radius due to its
asymmetries cannot reach higher than 20 miles. But if the rocket
is spun through 360 degrees every few hundred feet, the
20-mile-radius arc turns into a very suble corkscrew.

Imageine the modeler puts a very slight misallignment between the
forward and rear fins of a sidewinder. Suppose it's just one degree.
also suppose the fins are 1 foot apart. the rocket will naturally
arc in a circle with a 360-foot circumference and a 57-foot radius.
That's instant doom! make the error half as bad and you are in
trouble. But if the rocket spins every 10 feet, the path will be
a generally upward corkscrew, less than ideal performance, but
a safe flight.

So with model rockets, a spin on ascent is a good way to make a
marginal or asymmetrical model safe. Estes used to sell a space
shuttle orbiter kit that had a spin tab for this reason, and the
old Astron Space Plane had spin tabs as well.
---------------------------------------
6.17 How can I build a rocket with less wind resistance?

From: John DeMar (smd...@mailbox.syr.edu)

The best thing you can do is to NOT use launch lugs. Use a
launch tower instead. A polished, smooth finish makes a big
difference too. If the design allows, use a boattail and make
sure all transitions are smooth (from nosecones/payload sections,
etc.). Fin shape is a minor affect if they are relatively thin,
otherwise make sure the edges are at least rounded.

Here are some numbers for comparison:
Standard finish, no transitions, with lug: Cd = 0.88
Standard finish, no lug: 0.68
Polished finish, no lug: 0.61
Standard finish, no lug, 2:1 boattail: 0.52

Wolfram v.Kiparski

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Archive-name: model-rockets/scale
Rec-models-rockets-archive-name: rockets-faq/part07

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Last-modified: 1997 April 13
URL: http://dtm-corp.com/~sven/rockets/rmrfaq.toc.html


Rec.Models.Rockets Frequently Asked Questions: PART 07 OF 14

SCALE MODELING

NOTE: This section was originally edited for the FAQ by Bob Biedron, the
1992 FAI World Champion scale spacemodeler. It has since been
edited by others, including Buzz McDermott, Peter Alway, Sven Knudsen,
and Wolfram von Kiparski. Opinions expressed in this section should not
be taken as those of Bob, and should be considered a composite work of
submitters to this section in general, and not endorsements by any one
of the editors/submitters. A special thanks goes to Peter Alway for
extensive editing and additions to this section.
--------------------------------------------------------------
7.1 I would like to make a scale model of the <??> rocket. Where do I
start looking for technical data, dimensions, flight substantiation data, etc.?

A great place to start looking would be Peter Alway's book of scale data,
"Rockets of the World." This book was first published in 1993. A second
edition was published (hard cover only) in 1995. This book is a reference
collection of scale data assembled specifically for modelers. Peter also
has another book, "The Art of Scale Model Rocketry." This book is
describes scale modeling techniques, and includes limited scale data. It
also includes model plans and an index of scale data sources.
See Part 2 of the FAQ for address information.

Those wanting to construct detailed models may need additional data.
This usually presents something of a problem. Back issues of
"Sport Rocketry" and "American Spacemodeling" are a source of scale
information and detailed data. The old "Model Rocketry" and "Model
Rocketeer" also had a number of articles over the years. The last
three magazines are no longer in print. With the exception of articles
in AmSpam and SRM after 1990, all photos in the above mentioned magazines
are black and white.

If none of the above sources contain data on the prototype that you
want to build, or if you require more data than is found in these
sources, then two routes are open. First, ask around - someone may
already have data on the prototype that you seek. Many (most?) people
collect data without actually ever building a model. Others never get
around to publishing their data. NASA and the National Air and Space
Museum can be good sources of data (see addresses below). If you still
have no luck in finding the data you need, try writing the manufacturer
directly. The response you get from the manufacturer depends on a couple
of factors. First, your letter must end up on someone's desk who is
sympathetic to your cause and is willing to do some digging in the
archives. Second, the data you request must still exist! - often,
blueprints, photos etc. are thrown away after the manufacturer ceases
to produce the prototype. When writing a manufacturer, be as specific
as possible about the type of data you require, and explain why you
want the material. Peter Alway has further tips for tracking down
data in his book.

There is a surprising amount of scale data out there, from simple
overall configuration drawings to those showing screw/bolt dimensions.
The following list is derived from one Kevin McKiou submitted to this
newsgroup in February of 1992. Peter Alway added to it in November of
1995. It contains the majority of the scale data that has been published
in the model rocket literature to date, as well as listings of the
"private stashes" of a few individuals.
--------------------------------------------------------------
7.2 What are some specific sources for general scale data?

Available from NARTS (price below + 10% standard postage ($1.50 min)):

NARTS
P.O. Box 1482
Saugus, MA 01906
email: na...@nar.org
http://www.nar.org/NARTS

Aerobee 350-Full substantiation data with plans, three color
slides, and one b & W slide.
SP-1 $3.50

Aerobee Photos-Four 8 x 10 color photographs of the same Aerobee
350 flight as SP-1. These photos are slightly different views
than those in the SP-1 packets
SP-1A $10.50

ISQY Tomahawk-This packet contains plans, an 8 x 10 B & W photo,
and a history of this single stage sounding rocket which was
developed for the International Year of the Quiet Sun.
SP-2 $4.00

Super Loki Dart-This packet contains complete data including two
8 1/2 x 11 drawings, a label detail sheet, background information-
tion, color documentation, and four 8 x 10 B & W photos.
SP-3 $4.00

Sandhawk-This packet consists of a set of plans, history on the
vehicle, and an 8 x 10 color photograph of the vehicle on its
launcher.
SP-4 $5.00

Scale Data Reduction Sheets-Handy sheets for competition scale
packets. Includes spaces for scale factor, prototype dimensions,
and model dimensions. Set of 10.
SDRS $1.00

"Sport Rocketry Magazine" is the official publication of the National
Association of Rocketry (NAR). The address of the NAR is given else-
where in the FAQ. Prior to October 1993, the journal was titled
"American Spacemodeling". Scale data has been published on the
following:

Razumov-Shtern (w/SpSc model plans) Scale Nov/Dec 1996
Talos Missile Scale Summer 1996
Judi-Robin Balloon Dart Scale May/Jun 1996
Vostok (w/SpSc model plans) Scale Mar/Apr 1996
Hopi-Dart Scale Holiday 1995
Saturn IB Scale Jan/Feb 1995
Raven Scale Oct 1994
Saturn V (Overall view) Scale Aug 1994
N1 (colors) Sport Scale Aug 1994
N1 (dimensions) Sport Scale Jun 1994
Vanguard (B&W photo) Semi-scale Jan/Feb 1993
D-Region Tomahawk (color photos) Scale Jan/Feb 1992
Corporal Sport Scale Sep/Oct 1991
SCUD-B Sport Scale Jul/Aug 1991
Little Joe II-Part 2 (color photos) Scale Jul/Aug 1991
Little Joe II-Part 1 (color photos) Scale May/Jun 1991
Saturn V-Part IV-Apollo Spacecraft Scale Mar/Apr 1991
Saturn V Part III Scale Dec 1989
Saturn V Part II Scale Nov 1989
Saturn V Part I Scale Jul 1989
Delta Family Album-Pictorial Guide Sep/Oct 1990
Scout Sept 1988
Juno 1 Scale Jan 1988
Nike-Hercules Scale Aug 1984

"Rockets of the World: Second Edition"
by Peter Alway. 384 pages, hard cover.

THE DEFINITIVE SCALE MODELERS' GUIDE. Currently in print. See Part
2 of this FAQ for address.

Included in ROTW:

1. Dimensioned drawings, color-keyed drawings, B&W photographs, and
brief histories of selected rockets:
Germany:
- Maul Photo Rocket - Winkler's HW-2 - A-3
- V-2 (A-4) - OTRAG 1
The USSR, Russia and Ukraine:
- GIRD 09 - GIRD X - V-2-A
- V-5-V Vertikal 1 - V-11-A - M-100B
- MR-12 - MMR-06 - MR-20
- Sputnik - Vostok/Luna - Soyuz
- Small Cosmos B-1 - Large Cosmos C-1 - V-3-A Vertikal
- Proton - Tsyklon - N-1 moon rocket
- Zenit - Energiya-Buran
United States:
- Goddard's March 16, 1926 Rocket - Goddard's L-16
- American Rocket Society ARS-2 - Wac Corporal
- Bumper - Aerobee - Aerobee-Hi/150
- Aerobee 300 - Aerobee 150A - Aerobee 350
- Viking - Deacon - Deacon Rockoon
- Terrapin - Asp - Loki Rockoon
- Loki HASP - Super Loki Dart - Arcas
- Sparrow-HV Arcas - IRIS - IQSY Tomahawk
- D-Region Tomahawk - Sandia Tomahawk - Sandhawk
- Terrier-Sandhawk - Nike-Deacon - Nike-Cajun
- Nike-Asp - Nike-Apache - Nike-Tomahawk
- Nike-Smoke - Argo D-4 Javelin - Trailblazer I
- Taurus-Tomahawk - Hermes RV-A-10 - X-17
- Ram B - Shotput - Little Joe I
- Trailblazer II - Astrobee 500 - Astrobee 1500
- Astrobee D - Aries - Vanguard
- Juno 1/Jupiter C - Mercury-Redstone - Sparta-Wresat
- Jupiter - Juno II - Thor-Able
- Thor-Agena A - Delta B - Delta E
- Delta M - Delta II - MX-774
- Atlas-Score - Mercury-Atlas - Atlas-Agena D
- Atlas-Centaur - Scout - Little Joe II
- Apollo Pad Abort Test - Gemini-Titan II
- Titan IIIC - Titan IIIB - Titan IIIE
- Titan IV - Saturn I - Saturn IB
- Saturn V - Space Shuttle - Pegasus
- DC-X
France:
- Veronique - Vesta - Dragon III
- Diamant A - Diamant B - Diamant B-P4
Japan:
- Kappa 6 - Kappa 7 - Kappa 9
- Lambda 4S - Mu 4S - Mu 3S-II
China:
- Long March 3
United Kingdom:
- Skylark - Black Knight - Black Arrow
India:
- Rohini RH-75 - SLV-3
Argentina:
- Orion II
Australia:
- HAD - Aero-High
Brazil:
- Sonda 1 - Sonda 2
Canada:
- Black Brant II - Black Brant III - Black Brant IV
- Black Brant V - Black Brant X
Poland:
- Meteor 1 - Meteor 2K - Meteor 3
- RP-3 - Rasko 2
Spain:
- INTA-255
Europe:
- Europa - Ariane 1 - Ariane 4
- Maxus

Mail order Resources: Addresses for companies and institutions
selling scale drawings or photographs. Each drawing also provides
sources for more data in case you desire more detail.

Advanced Rocketry Group Ltd.
130 Matheson Blvd, East - Unit 10
Mississauga, Ontarion
L4Z 1Y6 Canada

Source of Ukranian and Russian launch vehicle scale data
Black Brandt series scale data


The Launch Pad
8470-H Misty Blue Court
Springfield, VA 22153
(703) 455-8418

Source of military missile scale data


"T minus 5" is the bi-monthly newsletter of the Huron Valley Rocket
Society (HUVARS) NAR Section #463. HUVARS is the NAR section with
which Peter Alway is associated. In the past it has been rich with
scale data and plans. Peter Alway has been a big contributor to
this and hopefully this tradition will continue now that Peter has
published his books.

Non-member subscriptions to "T minus 5" are $8.00 (U.S. and Canada)
and $11.00 elsewhere. Send correspondence to:

Jim Fackert
Huron Valley Rocket Society
10555 McCabe Rd.
Brighton, MI 48116

"Model Rocketeer" was the official publication of the NAR from
1971 through June, 1984.
Scale Data Published:
Nike-Tomahawk Scale Feb 1974
V-2 Scale Jun 1976
Trailblazer 2 Scale Nov 1980

"Model Rocketry" was published by George Flynn in the late 60's
and early 70's.
Scale Data Published:
Viking Scale Jan 1969
Asp Scale May 1969
Rohini RH-75 Scale Aug 1969
Little Joe II Scale Sept 1969
Nike-Smoke Scale Oct 1969
Nike-Apache Scale Nov 1969
Pershing Scale Jan 1970
HAD Scale Apr 1970
Vostok Scale Jul/Aug 1970
Falcon (AIM-4E) Scale Sept 1970
Skua Scale Oct 1970
Astrobee-D Scale Nov 1970
Aero-High Scale Oct 1971
D-Region Tomahawk Scale Jun 1971
Black Brant II Scale Dec 1971

Aerospace Industry/U.S. Government Contacts:

A very good source of photographs of NASA launch vehicles is the NASA
Photography Index which you can get for free by sending a request to:

NASA
Audio Visual Section, LFD-10
Public Affairs Division
400 Maryland Ave, S.W.
Washington D.C. 20546
(202) 453-8375
`
Photos can be ordered from the Index for a very reasonable cost.


National Aeronautics and Space Administration
History Office
NASA HQ LH-14
Washington, DC 20546

This source was recommended by a museum technician at the Smithsonian
Institution at the National Air and Space Museum (see following).

National Air and Space Museum
Archives (Bldg 12)
3904 Old Silver Hill Rd
Suitland, MD 20746-3190

Received prompt service (2 weeks) from Paul Silbermann, Museum
Technician. This is a part of the Smithsonian Institution.

Aerojet-General Corp.
1051 La Jolla Rancho Rd.
La Jolla, CA 92037

Builders of the Aerobee and Astrobee series of sounding rockets

---------------------------------------------------------------------
Display Locations
---------------------------------------------------------------------

* Aberdeen Proving Grounds Armaments Museum
Nike-Ajax on launcher, Nike-Hercules on launcher, Pershing II, US
Army missiles?, V-2 on carrier, Wasserfall, WWII German SAM?, V-1

* Air Force Armament Museum at Eglin Air Force Base, SE of Pensacola,
FL
Bomarc, Bullpup, Sidewinder

* Alabama Welcome Center, I-65 south, near TN-AL line
Saturn IB

* American legion Hall, Lakewood, NY
Nike-Hercules

* Ames Research Center, Mountain View,
Gemini 11?, Skylab 3?

* Neil Armstrong Museum, Wapakoneta, Ohio
Gemini 8

* Alabama Space & Rocket Center, Huntsville, AL
Apollo 16, Atlas, Corporal, Entac, Hawk, Hermes A-1, Honest John,
Juno I, Juno II, Jupiter, Lacrosse, Little John, Mercury Sigma
7?, Mercury-Redstone, Nike-Ajax, Nike-Hercules, Nike-Zeus,
Pershing, Redstone (tactical), Saturn I, Block 2, Saturn V,
Sergeant, Space Shuttle Mockup, Sprint, Titan I, V-2, X-15 mockup

* Astronaut Hall of Fame, Titusville, FL
Mercury Sigma 7?

* Bowfin Submarine Museum, Honolulu?, HI
Harpoon, Polaris A-1, Polaris A-3, Subroc, Tomahawk Cruise
Missile

* Centennial Park, Laurence, KS
Polaris A-1

* Octave Chanute Aerospace Museum, Rantoul, IL
Bomarc, Minuteman

* Museum of Science and Industry, Chicago, IL
Apollo 8, Arcas, Lunar Module, Polaris

* Combat Air Museum, Topeka, KS
Honest John, Nike-Ajax

* Cosmos Pavilion (now car showroom, some exhibits may
remain), Formerly of Exhibition of Economic Achievement,
Moscow, Russia
M-100B?, MR-12?, MR-20?, Vostok?

* Behind a Denny's, off I-75 near Warner Robbins, GA
Titan II

* Detroit Science Center, Detroit, MI
Nike-"smoke"

* Fireworks Factory, US 72, South Pittsburg, TN
Honest John

* Florence Air & Missile Museum, Florence, SC
Bomarc, Entac, Honest John, Sparrow, Titan I

* Fort Lewis Museum, Fortlewis, near Tacoma, WA
Honest John, Nike-Ajax, Nike-Hercules

* Fort Meade base museum, Fort Meade, MD
Nike-Ajax, Nike-Hercules

* Goddard Spaceflight Center, Greenbelt, MD
Delta-B, Gemini 12?, IRIS, Javelin, Nike-Black Brant, Nike-
Tomahawk

* Golden Gate National Recreation Reserve
Nike-?

* Grissom Memorial Museum, Spring Mill State Park, IN
Gemini Spacecraft

* Grissom Memorial Museum, Mitchell, IN
Gemini 3

* Aerospace Park, Hampton, VA
Corporal, Jupiter, Little Joe I, Nike-Ajax, Polaris A-2

* Hill Air Force Base Museum
Bomarc, Minuteman, MX-stage

* Hong Kong Space Museum, Hong Kong
Mercury Aurora 7?

* Airport road & S. Memorial Parkway, Huntsville, AL
Hermes

* VFW post on N. Memorial Parkway, Huntsville, AL
Corporal

* Illinois Soldiers & Sailors Home, Quincy, IL
Bomarc, Titan I

* International Space Hall of Fame, Alamogordo, NM
Aerobee 150 (2 displayed), Aerobee 170 tail unit, Arcas, Loki-Dart,
Falcon, Hawk, Lance, LM ascent engine, Javelin 4th stage motor,
Little Joe II (not accurate), F1 engine, J2 engine, V-2 engine,
Nike-Ajax w/launcher, Nike-Cajun, Syncom apogee kick motor,
Sonic Wind No. 1 rocket sled (Stapp's sled), XLR-11 engine

* ISAS, Sagamihara Japan
M2-SIII

* Japan Science Society, Tokyo
Gemini 11?, Mercury Aurora 7?, Skylab 3?

* Jordell Bank Radio Observatory Visitor Center, Cheshire, England
Skylark

* Jet Propulsion Laboratory, Pasadena, CA
Corporal, Sergeant

* Johnson Space Center, Houston, TX
Apollo 17, F-1 engine (Saturn V), Gemini 5, H-1 engine (Saturn I
or IB), J-2 engine (S-IVB, S-II), Little Joe II, Mercury Faith 7,
Mercury-Redstone, Saturn V

* Kansas Cosmosphere, Hutchinson, KS
Agena, F-1 Engine, Lunar Module Mock-up, Mercury-redstone, Nike-
Hercules, Titan I, Titan II engine, V-2

* Keesler Air Force Base, Biloxi, MS
Bomarc

* Kennedy Space Center
ASTP, Atlas-Agena, F-1 engine, Gemini 9, Gemini-Titan II,
J-2 Engine, Lunar Module, Mercury-Atlas, Mercury-Redstone, Saturn 1B,
Saturn V, Space Shuttle Orbiter mockup, Navaho SM-64 (X-10)

* 108th Light Anti-Aircraft Missile Batallion, North end
of Fresno Air Terminal, Fresno, CA
Hawk

* Leicester University Physics Department lobby, Leicester,
England
Skylark

* London Science Museum, London, England
Apollo 10, Black Arrow, Scout, Skylark

* Museum of Transport, Auckland, New Zealand
Gemini 12?

* Marshall Spaceflight Center, Huntsville, AL
Apollo LES-CM Boilerplate, Hermes A-1, Juno I, Jupiter, Redstone,
Saturn I, V-2

* McConnell Air Force Base, Wichita, KS
Titan II Re-entry Vehicle

* McDonnell Douglas, St. Louis, Missouri
Gemini 6?

* McChord Air Force Base Museum, Near Tacoma, WA
Sidewinder

* Miami Central High School, NW 95th St, Miami, FL
Honest John

* Michigan Space Center, Jackson, MI
Apollo 9, F-1 engine (Saturn V), H-1 engine (Saturn I or IB),
Mercury-Redstone, Talos, Tartar, Terrier

* Museum of Life and Science, Durham, NC
Mercury-Redstone

* Musee de l'Air, Paris, France
Apollo 13, Diamant A?

* Wallops Flight Facility Visitors Center, Wallops Island, VA
Aerobee 150, Astrobee F, High-speed reentry rocket, Little Joe I,
Nike-Cajun, Scout D

* National Air & Space Museum, Washington, DC
Aerobee 150, Agena stage (Gemini docking target), Apollo 11,
Apollo-Soyuz Mockup, Arcas, F-1 engine (Saturn V 1st stage),
Gemini 4, Gemini 4 spacecraft, Gemini 7, Gemini 7 spacecraft,
Goddard A-rocket, Goddard First Liquid, Goddard Hoop Skirt,
Goddard Pump Rocket, Goddard second liquid, H-1 engine (Saturn I
or IB inboard), Hale 24-lb rocket, Jupiter C (Juno 1), Lunar
Module, Mercury Freedom 7, Mercury Friendship 7, Mercury
spacecraft Freedom 7, Mercury spacecraft Friendship 7, Minuteman
3, Nike-Cajun, Pershing 2, Polaris (silver hill), Rheintochter,
Scout G, Skylab, Skylab 4, SS-20, V-2, Vanguard (late model),
Viking (model II), Wac Corporal, X-15

* National Atomic Museum, Albuquerque, NM
Honest John, Little John, Redstone, Minuteman, Thor, Jupiter

* Naval Serviceman's Park, Buffalo, NY
Talos (aboard USS Little Rock)

* National Museum of Science and Technology, Ottawa, Ontario,
Canada
Apollo 7

* Oakland Museum, Oakland, CA
Air-air missiles?

* Patric Air Force Base, FL
Atlas, Thor, Titan I

* Pima Air Museum and Titan Missile Museum, Tucson, AZ
Bullpup AGM-12B, Genie AIR-2A, Maverick AGM-65, Phoenix AIM-54,
Titan I, Titan II, TOW BGM-65

* Point Mugu Missile Park, Point Mugu, CA
Bat, Bullpup A, Bullpup A, Bullpup B, Bullpup B, Corvus, Hawk,
KDA, Lark, Oriole, Oriole, Petrel, Phoenix, Polaris A-1, Shrike,
Sidewinder, Sidewinder 1A, Sidewinder 1C, Sidewinder-Arcas,
Sparoair, Sparrow I, Sparrow I, Sparrow II, Sparrow III, Sparrow
III, Walleye

* Redstone Arsenal, Huntsville, AL
Redstone

* public park, Riverview, MI
Nike-Hercules

* Rockwell International, Downey, CA
Apollo 14

* Roswell Museum, Roswell, NM
Goddard Rocket components

* Science Museum of Virginia, 2500 West Broad Street,
Richmond, VA 23220 804-367-1013
Farside

* Selfridge Air National Guard Base, Mt. Clemens, MI
Tiny Tim

* St. Louis Science Center, St. Louis, MO
Black Brant XIII, Gemini 6?, Thor

* Stennis Space Center, near New Orleans, LA
F-1 engine (Saturn V), H-1 engine (Saturn I, IB), J-2 engine
(Saturn V, IB), Jupiter C, Space Shuttle ET, Space Shuttle SRB

* Strategic Aerospace Museum, Bellevue, NE
Atlas, Blue Scout SLV-1, Bomarc, Thor, Titan I

* Swiss Museum of Transport & Communication, Luzern
Gemini 10

* Morthon-Thiokol Corp, Brigham City, UT
Space Shuttle SRB, Trident Missile

* Tsiolkovski Museum, Kaluga, russia
M-100B, MR-12, Vostok

* US Naval Aviation Museum, Pensacola, Florida
Skylab 2

* U S Air Force History & Traditions Museum, San
Antonio, TX
Bomarc, Thor

* U S Air Force Museum, Dayton, OH
Aerobee, Agena A/Discoverer, Apollo 15, Bomarc, Falcon, Gemini
spacecraft, Jupiter, Mercury spacecraft, Minuteman I, Minuteman
III, Sparrow, Standard, Thor, Titan I, X-15, X-17, X-24

* U S Air Force Space Museum, Cocoa Beach, FL
Aerobee, Agena A, Agena B, Arcas launcher, Asset, Athena, Atlas
E, big shot shroud, Blue Scout, Bomarc A, corporal, Hawk, Honest
John, Jupiter, Lacrosse, Lark?, Little John, Minuteman I, Navaho,
Navaho engine, Nike-Ajax, Nike-Hercules, Pershing, Polaris A-1,
Polaris A-3, Redstone, Sparrow 1, Subroc, Tartar, Thor, Thor-
Able, Titan I

* public park, Warren, NH
Redstone Missile

* Virginia Air and Space Center, Hampton, VA
Apollo 12 capsule

* West Eight Mile Armory, Detroit, MI
Nike-Ajax, Nike-Hercules

* White Sands Missile Park, White Sands, NM
Aerobee 170, Aerobee Hi, Athena, Corporal, Crossbow, Dart,
Falcon, Genie, Hawk, Honest John, Lacrosse, Lark, Little John,
Loki, Nike-Ajax, Nike-Hercules, Nike-Zeus, Pershing, Pogo Hi,
Redstone (developmental), Sergeant, Shavetail, Shillelagh,
Sidewinder, SS-10, Talos, Tartar, Terrier, V-2, Wac Corporal
--------------------------------------------------------------
7.3 I've never built any scale models. Are there any recommended kits for
first timers?

The following recommendations have been made by posters to r.m.r:

For A-D powered rockets:
Estes IRIS (A-C power, sport/semi scale) - currently out of production
Estes Black Brant II (D power, sport/semi scale)
Quest Nike-Smoke (A-C power, sport scale)

Larger models:
North Coast Rocketry Patriot (E-G power, sport scale)
Aerotech ISQY Tomahawk (E-G power, scale)
Estes Terrier-Sandhawk (D-E power, scale, sport scale)
--------------------------------------------------------------
7.4 What other scale/sport scale kits are available? I'd like to build another kit or
two before tackling a scratch scale project.

Many of the really great scale kits (Estes LTV Scout, Centuri
Little Joe II, Estes Saturn 5) have been long since or recently
discontinued. Fortunately, there are still more than a FEW scale kits from
which a modeler may choose.

The following is a partial list of available scale and sport scale
rocket kits available as of December, 1996. A more complete list may be
found on the r.m.r. archive on sunsite.unc.edu. The archived list
includes non-flying, out-of-production and high power kits as well.

Apprx.
Rocket Kit# Man SL Comments Cost
Aerobee 350 MSHRK105 MSH 3 sportscale;56x2.6in 40.00
Aerobee Hi NRL-41 AAA 3 1/9;31.3x1.64in 22.00
Aerobee Hi NRL-41 AAA 4 1/6;49.25x2.6in 43.00
ALARM K001 TLP 4 44.5x2.6in 30.00
AMRAAM AIM-120A K048 TLP 4 1/2.69; 54.125x2.6in 33.00
ANUBIS K038 TLP 3 24.75X1.6" 13.00
ASM-1 (Type 80) K002 TLP 3 29.5x2.6in 25.00
A.S.P. RK-004 VBR 2 sport scale;83.8x3.4cm 25.00
A.S.P. MSHRK100 MSH 2 sport scale;34x1.64in 24.00
A.S.P. MSHRK101 MSH 2 sport scale;50x2.6in 35.00
ASRAAM K003 TLP 4 34.75x2.6" 25.00
Black Brant II EST 1958 ES 2 1/13; 63.2x3.37cm 13.00
Black Brant II 1014 FSI 5 1/8; 41.5x2.1in 36.30
Black Brant II COS 3 1:6 scale 51x2.46in 50.00
BOLO TLP 3 27.25X1.6" 14.00
Bullpup AGM-12B K005 TLP 4 1/4.62; 29.0x2.6in 25.00
Bullpup 12D EST 1972 ES 2 39.7x3.37cm 9.00
Corporal K-41 NCR 2 41.5x1.88in 35.00
DC-Y Space Clipper 3004 Q 3 Semi-scale;Height = 34.3cm
D-Region Tomahawk AAA 3 57.5x2.6in 45.00
Dragonfly TLP 3 26.5x1.6" 22.00
Exocet AM.39 K041 TLP 3 1/5.30; 34.875x2.6" 27.00
Exocet MM.40 K008 TLP 4 1/5.30; 42.0x2.6" 30.00
Falcon AIM-4C TLP 4 31.5x2.6" 27.00
Flail TLP 3 29x2.6" 25.00
Gabriel III/AS K010 TLP 4 30.25x2.6" 27.00
Gemini-Titan BOY 3 1/100; 12x1.2 in.
Gemini-Titan BOY 2 1/160; 8.5x0.736 in.
Grail SA-7 TLP 3 31.25x1.6" 15.00
Harpoon AGM-84A TLP 4 29.25x2.6" 27.00
Hawk MIM-23A K035 TLP 4 1/5/45; 37.0x2.6in 27.00
Hawk CLR 3 2.6in diam. 32.50
Hellfire AGM-114A TLP 3 23.625x2.6" 25.00
Honest John BOY
IRIS MSHRK104 MSH 3 sportscale;50.75x2.6in 39.00
ISQY Tomahawk 2005 Q 2 sport scale;47.6x2.0cm
ISQY Tomahawk 89014 AT 3 104x4.7cm 43.00
ISQY Tomahawk AAA 4 len=146cm 45.00
Javelin 1025 FSI 5 1/10; 55.3x2.25in 42.00
Jayhawk EST 2085 ES 4+ 1/5; 76.2x6.35cm 36.00
Jayhawk CLR 4 1/5; 2.6in diam. 29.00
KORMORAN AS.34 K015 TLP 4 1/5.20; 33.3x2.6in 25.00
Lance MGM-52 K042 TLP 4 1/8.48; 28.75x2.6in 23.00
Martel As.37 K053 TLP 4 1/6; 27.0x2.6in 27.00
Maverick AGM-65B TLP 3 21.5x2.6" 25.00
Mercury-Atlas ES 4 1/35; len=33in 50.00
Mercury-Atlas BOY
Mercury-Redstone BOY 5 1/17.5; 58x4 in.
Mercury-Redstone BOY 3 1/100; 9.75x0.736 in.
Nike Ajax MIM-3A K060 TLP 4 55" long 50.00
Nike-Apache COS 4+ 1/6;52.5x2.63in 55.00
Nike-Smoke COS 4+ 1/6; 36.5x2.63 45.00
Nike Smoke 1030 FSI 4 1/8; 72.6x5.1cm 29.00
Nike Smoke 2007 Q 2 49.5x3.5cm 7.00
Nike-Smoke SRW 3 1/30; 7.64x0,55in 6.50
Nike-Smoke BOY 1 1/22; 10.5x0.736 in.
Nike-Tomahawk 1023 FSI 5 1/8; 46.0x2.0in 34.00
Patriot EST 0896 ES 1 mini-motors; 25.4x1.878cm 4.40
Patriot EST 2066 ES 4 1/5;99x7.62cm; 4 motor clstr 60.00
Patriot K-85 NCR 4 1/4;140.7x10.2cm 60.00
Patriot THOY 4 1/4;132x10.2cm 60.00
Patriot PML 4 1/4;132x10.2cm 60.00
Pershing 1A BOY 2 1/30; 8.5x0.736 in.
Perseus TLP 3 26.25x1.6" 17.00
Phoenix EST 1380 ES 3 1/9 (semi); 76.2x6.6cm 21.50
Phoenix AIM-54C TLP 3 25.75x2.6" 29.00
RP-3 ASP 2
Sandhawk CLR 3 1/5; 2.6in diam. 38.50
Sandia Sandhawk 1031 FSI 5 1/6; 49.0x2.0in 33.00
Saturn 1B BOY 2 1/396; 6.8x0.736 in.
Saturn V BOY 1 1/396; 10.7x0.976 in.
Scimitar TLP 4 39.25x2.6" 32.00
Sea Wolf K052 TLP 4 1/2.72; 29x2.6in 33.00
Sergeant CLR 3 3.1in diam. 38.50
Sidewinder AIM-9L K030 TLP 4 36.0x1.6in 26.00
Space Shuttle EST 1284 ES 4 1/162; len=34.5cm 25.00
Sparrow AIM-7F TLP 3 46.75x2.6" 29.00
SR-71 Blackbird EST 1942 ES 3 semi-scale; len=48.3cm 16.00
Standard AGM-78 K032 TLP 4 1/5.2; 34.6x2.6in 29.00
Standard ARM LS-101 MRC 2 1/14 (sport);25x1.17in
Standard ARM CLR 3 2.6in diam. 32.50
TAN-SAM (Type 81) K045 TLP 4 1/2.42; 44.0x2.6in 31.00
Terrier/Sandhawk EST 2083 ES 4+ 1:9.8; 116.8x4.66cm 31.00
Trailblazer LS-104 MRC 4 1/17;34.3x1.75in
Type 30 Art. K049 TLP 4 1/4/54; 40.75x2.6in 25.00
V-2 MSHRK103 MSH 2 1/25sportscale;22.5x2.6in 22.00
V-2 MSH 3 1/16.25sportscale;31.5x4" 60.00
Vostok COS 5 1:33 scale 45x3.1in 130.00
Wasp 1024 FSI 5 1/8;34.75x2.0in 39.60

There are also a number of Ready-to-fly (RTF) and Almost-ready-to-fly
(ARTF) flying rockets, if you want 'minimal' build time:

Honest John 5050 COX 1 1/24;len=13in 17.00
Saturn 1B 5025 COX 1 len=21.5in 34.00
Saturn V 5075 COX 1 len=34in 54.00
X-15 5000 COX 1 1/24 21.00

Some recently discontinued scale kits which you can still
occasionally find on hobby store shelves include (all of the below
were in the 1991 catalogs or later):

Honest John EST 1269 ES 3 1/9;94x6.6cm 40.00
IRIS EST 2007 ES 2 1/13; 17.125x.976in 7.00
Little Joe II EST 0892 ES 3 1/100;26.7x3.91cm 12.00
Mercury Redstone EST 1921 ES 4 1/35; 28.75x2.0in 20.00
Patriot EST 2056 ES 2 1/10 (semi);54x4.16cm 10.00
Saturn 1B EST 2048 ES 4 1/100;67.2x6.65cm 42.00
Saturn V 25th Anv. EST 2001 ES 4+ 1/100; 109.9x10.0cm 53.00
Sidewinder TR108 MRC 2 1/4 (sport);30.28x1.325
Titan IIIE(1) EST 2019 ES 4 1/73; 71.1x5.64cm 26.00/19.00

You say you like scale models, but want something BIGGER?? Try one of
these:

AMRAAM PML 4 56x3in 80.00
AMRAAM PML 4+ 73x4.0in 100.00
Astrobee D 89015 AT 4 1/2.5; 173x6.7cm 70.00
Hawk CLR 4+ 4.0" diam.; 54mm 78.00
HV Arcas 89012 AT 3+ 1/1.666; 142x6.7cm 50.00
Jayhawk CLR 4+ 4.0" diam; 38mm 58.00
Patriot PML 4+ 1/2; 97x7.5" 260.00
Sandhawk CLR 4+ 4.0" diam.; 54mm 93.00
Standard ARM CLR 4+ 4.0" diam.; 54mm 78.00
Standard ARM CLR 4+ 7.67" diam.; 5x54mm 245.00
Sandhawk CLR 4+ 5.54" diam.; 54 + 2x29mm 185.00
Navy Strike CLR 4+ 4.0" diam.; 54mm 93.00


Nomenclature Key:
SL = Skill Level (1 = Beginner, 5 = Advanced)
Prices are approximate retail prices in U.S. dollars
Man = Manufacturer (Refer to Part 02 for addresses)
AAA AAA Model Aviation
ASP Aerospace Specialty Products
AT Aerotech
BOY Boyce Aerospace Hobbies
CLR Cluster R
COS Cosmodrome Rocketry
ES Estes Industries
FSI Flight Systems Inc.
MSH Mountainside Hobbies
PML Public Missiles, Ltd.
Q Quest
SRW Seatle Rocket Works
THOY Tiffany Hobbies of Ypsilanti
TLP The Launch Pad
VBR Vaughn Brothers Rocketry

NOTES:
1. Dual prices reflect last full retail price and special 'closeout'
price offered by manufacturer. Kits with both prices may still
be found on hobby shelves.
--------------------------------------------------------------
7.5 O.K., I've done all my research, collected all the data I can.
I've even built a couple of scale kits a a warm up. Now I'm ready
to build a model I can be proud of. How do I...?

Get rid of body tube seams:
Use silkspan, applied with clear dope, or .5oz. - .75 oz. fiberglass
cloth applied with epoxy. Silkspan will require a number of
subsequent coats of dope or primer to seal the surface and fill in
the fibers of the material, while the fiberglass should only require
a few coats of primer to fill in the weave. Really deep seams in the
tube should filled with your favorite putty beforehand. Tubes covered
with silkspan/fiberglass will be less likely to have the seams pop
later on.

The suggestions given in part 06 and 11 are both useful and applicable.

Sand sharp break lines in fins with diamond cross sections, like those
used on Nike motors:
You can't...use a built-up fin instead. Use 1/64 ply or thin plastic.
Cut out mirror images of the fin pattern, then score the breakline
with the back of an Xacto knife, being careful not to cut all the way
through. Gently bend at the break line. Use a spar under the breakline
to provide support and give the proper root to tip thickness
distribution. Glue the three pieces (two fin halves and spar)
together, and fill the open ends with wood and/or putty.

Form sharp edges on nose cone, transitions, etc. (when turning your own):
The most common material to turn these items, wood (balsa, bass)
just won't take a very sharp edge. Try forming the piece slightly
undersize, then apply several coats of epoxy (try to get the coats
as even as possible). Then use a sanding block to sand the surface
smooth, but don't sand all the way down to the wood. These steps
should be done without removing the part from the lathe. The epoxy
will hold a better edge than wood, and the resulting surface will
have a plastic-like feel. Make sure the epoxy you use will cure to
a hard surface in thin films...5 minute epoxy often remains somewhat
rubbery.

Simulate weld lines:
Thread can be used, but something with a flatter cross-section
usually looks more realistic. Try cutting very narrow strips
of thin plastic using two X-acto or razor blades glued together (may
need a plastic spacer between the blades to get the desired width).
The width and thickness of the strip will of course depend on the
size of the weld to be simulated, but a 2:1 or 3:1 width:thickness
ratio is about right. Paint the model body tube with primer
let dry and apply the plastic strip with a _small_ amount of liquid
cement. Use a strip of frisk film or masking tape to provide an edge
to insure the plastic strip gets applied straight. Then apply several
coats of primer to fair in the edges, sanding between coats. If
AmSpam ever gets around to publishing it, a future "Art of Scale"
will cover this in more detail.

Simulate screws, bolts, and rivets:
For large-scale models, you may be able to find small screws in sizes
0-80 or 00-90 that will do the job that will do the job (Small Parts,
Inc, P.O. Box 4650, Miami Lakes, FL 33014-0650 is one source). On
smaller models you can simulate screws by embossing slots into Sig
"scale rivets" with an X-acto blade. Sig scale rivets are available in
both round and flat-head varieties (Sig Manufacturing Co., Inc., 401-7
South Front St., Montezuma, IA 50171). To simulate really tiny screws,
emboss the shafts of the scale rivets. Socket head screws can also be
simulated using scale rivets by drilling or punching a hole in the
center of the head. Rivets can be simulated in a variety of ways. On
large scale models, Sig scale rivets may be appropriate. For small
models, the best (and most difficult) way is to emboss thin sheet
material (aluminum or plastic) using a punch and die. This method gives
very sharp definition to the rivet heads. An easier way that produces
less definition of the rivet head is to simply punch from one side of
the sheet only - no matching die is used. This allows the use of a
small spur gear (e.g. a watch gear or pounce wheel) as the punch,
thereby allowing a whole row of rivets to be punched very easily.
A sewing machine can also be used to punch a whole row in short order -
just grind down a needle to produce the correct size rivet head. Model
airplane types often use tiny drops of glue to simulate the rivet
(RC56 glue supposedly works well).

Make multiple copies of parts:
Often, an number of identical parts appear on a prototype, and it is
usually tedious to make just one of them. RTV rubber is a two-part
rubber compound that cures at room temperature. Space does not allow
a detailed discussion of the method here, but basically a high-quality
master pattern is made, over which the RTV is poured. When cured,
the rubber mold is removed. Epoxy or urethane resin can then be
poured into the cavity to make as many copies as desired at a small
fraction of the work needed to make the master. Fiberglass parts can
also be laid up in RTV molds (another yet-to-be published AmSpam/SRM
article). Check out back issues of "Fine Scale Modeler" magazine
for a number or articles on casting parts in RTV molds. This is an
_extremely_ valuable technique for the serious modeler.

Refer to sections 06 and 11 for other relevant tips.

--------------------------------------------------------------
7.6 What tools do I need?

Well, that's kind of up to you....and your checkbook. With lots of
ingenuity and perseverance, many things can be done with simple tools.
For example, nose cones and transitions can be turned with just an
electric drill (small sized ones at any rate), but it's sure a lot
easier with a lathe (see Alway's book for details on turning with a
drill). An airbrush is almost a must to have, since even the cheapest
spray gun will (with practice) give a much better finish than a spray
can. Cans of propellant to operate an airbrush are available, but are
expensive in the long run; a portable air tank (found in many hardware
stores) could provide a refillable, cheap (free from service stations)
source of air for under $30. However, having a compressor is by far the
most convenient (if you live in a humid clime, you will also need a
moisture trap). Any precision scale work will require some measuring
tools, typically a steel ruler with 1/100 inch graduations and a
caliper are sufficient. Enco Mfg., a large machine tool supplier, offers
a line of low cost rulers and calipers. Their number is 1-800-873-3626.
Those who are really serious about scale modeling and have the $$$ to
spend may want to consider a small milling machine in addition to a
lathe (small lathes like the Sherline or Unimat offer an optional
milling column). With a lathe and mill, almost anything can be
fabricated, subject only to the skill of the operator and the size
of the machine.
--------------------------------------------------------------
7.7 Where can I get more information on modeling techniques?

Since scale modeling is such a small segment of model rocketry, there's
not much "how-to" info in the model rocket literature. Peter Alway gives
some basic, low-tech tips in his book. For more advanced techniques,
look in magazines for the plastic model enthusiast: "Scale Modeler" and
"Fine Scale Modeler" are two examples. Useful techniques also appear
occasionally in the model airplane model and ship magazines.
--------------------------------------------------------------
7.8 Got any tips for generating scale plans from original dimensions?

Peter Alway (Pete...@aol.com) suggests an old fashioned shortcut for
generating scale plans:
I find a slide rule is better than an electronic calculator for
scheming up scale models. You just set the proportion of prototype
diameter to a standard body tube diameter and slide the sliding
doohickey back and forth to find dimensions of all the other parts.

Jack Hagerty (ja...@rml.com) counters with a more modern version:
Not to sound too snobby, but I have an even better way to make perfect
scale drawings of every piece AUTOMATICALLY. Use a CAD system. Even
the cheap ones (cheap meaning ~$100) usually have a scaling function.
On mine its one of the commands under the "Copy" function.

CAD systems don't care if the screen is a mile across or .01" across;
it's all just numbers. When I did my Titan IIIB, the sceen was set to
be about 2,000" across (the Titan/Agena is about 1,700" from tip to
the bottom of the engine bells). You just draw in all of the peices
from your prototype reference data full size. Then, when you're done,
you invoke the scale command to do essentially what Peter alluded to
above using the diameter of the prototype and diameter of the body
tube you're going to use to set your ratio.

Continuing my example, the Titan is 120" in diameter and I used Estes
BT-80 (2.62" dia) to build it. Once I had drawn the prototype I
invoked "Copy -> Scale -> 2.62/120 -> All" and presto! Every piece,
every conduit, every strut was now the correct scale size. I just
plotted it full scale on my plotter and I had the perfect layout
pattern.

Mark Bundick (mbun...@inil.com) adds:
Try using a spreadsheet. They are particularly useful in cases where
there are station numbers instead of actual dimensions in the drawing.

In column 1, enter the part name or dimension. In columns 2 and 3
enter the station numbers from drawing. In column 4, enter a formula
to take the difference between the figures in column 2 and 3. In
column 5, enter a formula to apply your scale factor to the figure in
column 4.

If you want to model in a different scale, just change your scale
factor and new dimensions are generated for every part you need on our
upscaled or downscaled bird. I find it particularly helpful to just
add different body diameters in different columns and then print out a
whole page of dimensions for various sized birds.

Wolfram v.Kiparski

unread,
Sep 26, 2000, 3:00:00 AM9/26/00
to
Archive-name: model-rockets/gliders
Rec-models-rockets-archive-name: rockets-faq/part08
Posting-Frequency: monthly
Last-modified: 1996 April 26
URL: http://dtm-corp.com/~sven/rockets/rmrfaq.toc.html


Rec.Models.Rockets FAQ (Frequently Asked Questions): PART 08 OF 14

BOOST GLIDER AND ROCKET GLIDERS

8.1 R/C Rocket Gliders

The D-G powered R/C rocket gliders now available are presenting some new
problems to ModRoc'ers, who are more used to making balsa wings, fins, etc.,
then built-up wings. Here is a set of tips submitted by Iskandar Taib, a long
time model plane enthusiast, and others. There is an excellent FAQ in the
rec.models.rc news group. It includes very good information on how to get
started into R/C flying, tips on where to buy equipment, etc.
------------------------------------------
8.1.1. Have there been any construction reviews of R/C rocket gliders?

Aerotech Phoenix: August, 1992, "Model Builder Magazine"
Estes Astroblaster: September, 1992, "Model Builder Magazine"

Both articles are written from the perspective of experienced R/C
aircraft modelers. They both contain good construction and flying
tips.
------------------------------------------
8.1.2. I'm building the 'XXX' R/C Rocket Glider and it uses foam core wings.
Are there any things I should know about working with foam?

The first thing to know is that certain paints and glues dissolve
foam. Both the stuff made out of white beads (referred to as "bead-
board") and the blue (Dow Styrofoam (tm) ) or pink (DuPont Foamular)
extruded foam will behave in the same way. Once sheeted a foam wing
can sometimes be finished in a paint that ordinarily dissolves foam
if one is careful about not putting too much on at a time. Here is
a list of what will dissolve styrofoam and what won't:

Will dissolve foam:

Nitrate and butyrate dope
Ambroid
"Model Airplane Cement" (you know what I mean)
Polyester resin (sold as "fiberglass resin" at K-Mart)
Thick and thin cyanoacrylates (excepting UFO)
Paints from spray cans
Dope and paint thinners
Gasoline
Dope thinner, acetone
Solvent-based contact cements

Won't dissolve foam:

Polyurethane paints and varnishes (inc. Rustoleum)
White or aliphatic glues (Elmer's, Titebond)
Epoxies
Ethanol or methanol (sometimes used to thin epoxies)
UFO superglues
Water-based contact cements (eg. Southern Sorghum)

Follow the instructions provided and you won't go wrong. Most struc-
tural building is done with white glue and epoxy is used for sheeting
the wing and/or putting down fiberglass, graphite or kevlar cloth.
------------------------------------------
8.1.3. Any tips for sheeting the wings on my Aerotech Phoenix?

The Phoenix kit requires that you sheet the wing with balsa using epoxy
as the glue. Aerotech also recommends that you vacuum-bag the wing for
the lightest wings possible. Vacuum bagging is a fairly new technique
that I will describe later.

The process involves preparing the wing skins, mixing the epoxy (need-
less to say, the 24 hour laminating variety, spreading it on the skins
with a squeegee, scraping most of it off, applying the skins to the
core, then assembling everything together in the core beds (the pieces
left over after the core is cut), and putting lots of weight on top
of the whole thing. Oh yeah.. the wing has to be kept straight so
you'd have to do this on a very flat surface. The more pressure you
can put on this, the better glue joint you'll have, and the less glue
you'll have to use, which makes for a lighter wing.

VACUUM BAGGING

This is where the vacuum bagging comes in. The core bed/sheeting/core
assembly is put into a large bag which is sealed on all sides. Then the
air is pumped out of the bag. This is supposedly the equivalent of pi-
ling hundreds of pounds of weights on the core. In fact they tell you
to limit the vacuum to so many inches Hg otherwise the cores will crush.

Vacuum bagging is also useful if you are going to lay up fiberglass
on top of the balsa wing skins. Fiberglass cloth is now available in
very light weights and people often use it in lieu of a covering film
or fabric.

The way it used to be done was that the cloth was laid down and a thin-
ned (with alcohol) epoxy brushed into it. Then excess epoxy was removed
using rolls of toilet paper (discarding layers as they became saturated).

With vacuum bagging one lays down a sheet of drafting mylar on top of
the wet glass cloth, then puts the assembly in core beds. The assembly
is then vacuum-bagged. After curing the mylar sheets are removed and
you end up with a glass-like finish that is extremely light since all
excess epoxy has been squeezed out. This also obviates the need for
lots of the filling and sanding usually necessary before painting.
------------------------------------------
8.1.4. How about help with my Estes Astroblaster wings?

The Astro Blaster kit uses contact cement for sheeting the wings. The
cement is of the water based variety. It is applied to both skin and core
and is allowed to dry. After this has occurred, the skins and core can
then be brought together. This is a little trickier, since you don't get
a second chance.. Once the core touches the skin you can't separate them
without breaking something. The skins are just 1/32" thick so one
has to be gentle with them.
------------------------------------------
8.1.5. How do you repair damaged foam wings?

Repairing foam is fairly easy. One simply hacks out the damaged piece,
glues in a block of foam and carves and sands to shape. Carving is best
done with a brand new utility knife (the kind that has break-off points)
and sanding can be done with a sanding block. Sheeting is replaced in
the same manner - cut out the damaged piece and glue on a replacement.
A little glass cloth or carbon fiber matte over the break helps too.
------------------------------------------
8.1.6. Some more uses of foam in rocketry...

Foam is interesting stuff to play with. You can cut wing cores using a
hot wire and 1/16" ply or formica templates. Parts for rockets can be
made by simple carving and sanding.

Even more interesting is making lightweight wings and other parts using
foam, silkspan and thinned white glue. Someone called Ron St. Jean built
lots of competition free flight models in this manner. The silkspan is
applied wet over the foam, and thinned white glue is brushed on. When
the silkspan dries it shrinks, and the result is an incredibly strong and
stiff structures. One could conceivably use this method for nose cones
or complex scale models. In England, foam and brown wrapping paper is
used for complex ducted fan models (someone actually flies a seven foot
long scale Concorde constructed like this).

If one uses heavier paper (eg. grocery sacks) perhaps one can dissolve
the foam once the white glue is set (use acetone or dope thinner for
this). For rockets imagine something shaped like a V2 made like this.
Once the foam was dissolved you'd end up with a light weight craft paper
tube of the proper shape, boat tail and all.
------------------------------------------
8.1.7. I need to cut the piano wire control rods. Bolt cutters don't work
well, as the metal is too hard. Any ideas?

From: nt...@silver.ucs.indiana.edu (Iskandar Taib)
What you want to do is get your hands on a reinforced cutting wheel
like the House of Balsa Tuf-Grind. The Dremel ones tend to shatter and
throw pieces at high speed. If you use them harden them with thin
superglue.
------------------------------------------
8.2 Free Flight Boost and Rocket Gliders

Copyright (c) 1996 by Robert G. Kaplow. Permission granted for non-profit
distribution and may be reproduced by any group or individual for
non-profit use, provided that the source and author of this document is
acknowledged. The distribution and reproduction of this document for
commercial use without permission of the author is specifically denied.
Any other use requires the permission of the author.
Feedback can be sent to Robert...@hccompare.com.
------------------------------------------
8.2.1 What is the difference between a Boost/Glider and a Rocket/Glider?

In a Boost/Glider (referred to as a BG in the rest of the FAQ), only a
portion of the rocket as launched is required to come down gliding. In a
Rocket/Glider (RG), the entire model remains in one piece, and the whole
thing glides down. Typically, this distinction is only important in NAR
competition, where these two classes are distinguished. An RG is a legal
entry in BG events, but a BG is not a legal entry in RG events.

The other thing to distinguish is a philosophical distinction between a
BOOST/glider and a boost/GLIDER. The question is which half of the flight
the emphasis is on. A BOOST/glider is a rocket that happens to have glide
recovery. In reality, it probably doesn't glide that well. The Space Shuttle
kit is a good example of this type of glider. A boost/GLIDER on the other
hand is a high performance glider that is carried aloft by a rocket motor.
These are the type of models typically seen in competition, and the topic of
most of this FAQ.

Also note that regardless of the emphasis, all of these gliders are launched
vertically, like other model rockets. Horizontal launch and shallow climbing
supported by wing lift doesn't work for these models, and is prohibited by
the safety code.
------------------------------------------
8.2.2 What are some types of gliders?

Early BGs were rear engine designs. The first was built by John Schultz and
Vern Estes in 1961. They usually looked like delta-winged jets or X rockets.
The old Estes Space Plane is an example of this style.

In 1963 Larry Renger invented the front engine BG with the Sky Slash design
winner. It was basically a hand launched glider with a motor pod hung on the
front. The old Estes Falcon followed this style. A few years later, Larry
invented the detachable "pop" pod. Almost all gliders today are front engine
design, and pop pods are the most common of the BGs flown today. The old
Centuri Swift and Estes Dragonfly were Pop Pod designs.

Parasite gliders are small gliders attached to the outside of larger
conventional model rockets. They can be as simple as a small foam glider
hooked to an extra launch lug on the side of a standard model rocket. Many
of the popular mass market kits fall into this category, including the Estes
Manta, ARV Condor, Space Shuttle and the old Orbital Transport, and the
Quest Aurora.

Flex-wing (FW) gliders were inspired by the Rogallo wing that was intended
as the recovery device for the Gemini program. They are basically 3 sticks
with a lightweight plastic covering. They fold for boost inside a long
skinny rocket, and eject like a parachute. NAR competition rules prohibit
"flexies" as they are called in BG and RG events, and create a separate
category for them.

Gliders are further broken down into categories describing how they look or
work. Some of them are fixed pod, pop pod, swing wing, slide wing, box wing,
t-rail, slide pod, no moving parts, canard, auto-elevator, variable camber,
flop wing, scissor wing, flying wing, swept wing, delta wing, Rogallo wing,
etc.
------------------------------------------
8.2.3 What are all these funny names I see referenced?

Until the 1979 Pink Book revision, different power classes were designated
by names. For gliders, the names were of flying creatures. Here is a decoder
table:

1/4A Gnat
1/2A Hornet
A Sparrow
B Swift
C Hawk
D [no official name, sometimes called Deagle or Falcon]
E Eagle
F Condor
G [no official name, but commonly referenced as Dragon]
------------------------------------------
8.2.4 I'm just starting. What kits or plans are available?

Several model rocket manufacturers make glider kits. Very few make really
good gliders. Among the non-spectacular performers are the Estes Space
Shuttle and Tomcat, and assorted parasite and foam gliders.

The Quest Flat Cat is an improvement on an old design that can fly
reasonably well. QCR has several glider kits, including a good booklet on
flex-wing gliders. Edmonds Aerospace offers several glider kits. Eclipse has
a few glider kits as well. The Estes Trans-Wing and MRC Thermal Hawk are
reasonable fliers. Apogee had glider kits, but I don't know what their
status is today. NCR glider kits are gone, but plans may resurface in the
future.

My favorite BG plan for the beginner is the Flanigan Flyer, designed by
Chris Flanigan of the MIT Rocket Society. Plans for it can be found in the
MIT Competition Notebook available from NARTS. It is suitable for A-C 18mm
motors. Guppy's Fish & Chips (1/2A) and High Performance Sparrow (A) BG were
some of my favorites, but are very touchy to trim (more about that later).
Try Mark Bundick's Parksley Eagle for 13mm 1/2A & A motors, available from
NARTS in the "NIRA Glider Plans from 'The Leading Edge'" reprint. There are
several other glider related NIRA Reprints also available from NARTS.

[I'm looking for a C/D BG recommendation - rgk]

For a first RG, I recommend the Seattle Special, by George Riebesehl. Plans
for this model are also in the "NIRA Glider Plans from 'The Leading Edge'"
reprint. It flies on A-C 18mm motors.

[I'm looking for a 1/2A RG and C/D RG recommendation - rgk]


For a FW, I recommend the QCR kit and manual. This proved good enough for
NAR V.P. Trip Barber, a fellow FW hater, to take a first place with at
NARAM-37, building the glider on the field. Also refer to George Gassaways
articles in American Spacemodelling, December 1980 and September 1986.

Many more plans are available from NARTS or NARTREK publications.
------------------------------------------
8.2.5 Why do most gliders have the rudder under the fuselage?

This is probably more for historical rather than technical reasons. Since
the motor is on top, a conventionally placed rudder would be in the exhaust.
In reality, some glider tails are far enough from the exhaust that it
doesn't matter. The real question should be "Why do airplanes have the
rudder on top?" :-)
------------------------------------------
8.2.6 These things are very different from what I've built before. Are there
any tips for building them?

Lots of them. The most important things to consider are to build light,
strong, and warp-free. Weight is the enemy of a glider. A weak glider will
break easily. A warped glider is very difficult to make glide properly. All
three of these problems are hard to fix later.

In order to keep surfaces straight, I recommend the use of a building board.
A scrap of kitchen counter, larger than the finished model is perfect for
this purpose. All planing, sanding, cutting, and gluing is done on this work
surface. It should have at least one straight perpendicular edge.

The flying surfaces of a glider need to be airfoiled to work best. Unlike
other rocket parts, a glider wing needs a non-symmetric airfoil. The standard
fin airfoil shape, split in half, is a good place to begin. To rapidly shape
a wing airfoil, use a device called a razor plane. Much like its big brother
used for carpentry, this tool shaves off wood quickly. The difference is
that it uses a razor blade or equivalent to do so. Many different types are
available. My personal favorite is the David Combi. An inexpensive nylon one
is available from Master Airscrew. These and many other handy tools can be
found in model airplane catalogs. The SIG catalog in particular is an
excellent source of many materials needed to build and fly gliders,
including these two razor planes.

Once roughly shaped, a sanding block is needed to get everything smooth. A
6" piece of 1x2 is perfect to wrap 1/6 of a sheet of sandpaper around (or
1/3 of a sheet around a 12" block). Use thumb tacks to hold the sheet in
place. Sanding across the grain removes wood fast, sanding with the grain
gives a nice final finish. Start with 100 grit, and work down to 400. The
stab and rudder are similarly airfoiled, usually symmetrically.

In order to glide, your glider will need dihedral. This is the upward
tilting or curving of the wings. Some designs use multiple joints, trihedral
or polyhedral. To do this, cut the wing in half (or thirds, quarters, etc.
as per the plan). A razor saw is the best tool to do this, but a modelling
knife and a straight egde will do. Tilt each tip up the required amount on
your building board. Use a handy scrap or a piece of 1x2 to prop the wing
pieces up. Now bevel the root edges using a sanding block and the edge of
the building board so that they are once again perpendicular to your work
surface.

The two edges can now be glued together. Standard wood glues can be used for
this, either carpenters, CA, epoxy, or Amberoid or Duco. I particularly like
Amberoid or Duco cement for gliders because it can be dissolved to remove
parts that end up misaligned.

The wing, stab, and rudder are now glued to the fuselage of the glider. Take
care to align things accurately. Typically a design will call for a tilt in
the wing or stab, in order to make the glider gently turn in flight. This
prevents very long chases to retrieve your glider. Also designs will
frequently include a few degrees incidence in the stab. By putting the stab
at a slight angle to the wing, it aids in the transition of the glider from
boost to glide, and prevents the "death dive" where the glider flys straight
down.
------------------------------------------
8.2.7 Should I paint my glider?

Most competition models are not painted in a normal sense. Many gliders are
left unpainted at all. Some modelers will color the model with magic marker
or a thin layer of model airplane dope for visibility. Others will apply a
coat or two of clear dope to prevent warping. I personally prefer Jap Tissue
and dope (discussed later), as it adds both strength and color to the model,
at a very minimal weight penalty.

Conventional finishing techniques of filler, primer, paint, and decals
should be left to models where glide performance is not a concern.
------------------------------------------
8.2.8 Can I convert a hand launched glider (HLG) to rocket power?

Yes. The cheap balsa "snap together" toy gliders (i.e. North Pacific) are
*NOT* strong enough for flight conversion, however many HLG kits and plans
are convertible. Plans for Jetex models are usually too flimsy for model
rocket power. A wealth of HLG plans are available from the Academy of Model
Aeronautics (AMA), National Free Flight Society (NFFS), Zaic yearbooks, and
some of the other RC modeling magazines. I highly recommend the NFFS
newsletter and journals as sources of free flight glider information.
Usually, all you need to do is to add a pop pod to the HLG, and perhaps
invert the rudder.

The references at the end of this part of the FAQ list several good HLG
plans.
------------------------------------------
8.2.9 I'd like to design my own glider. How do I know if it will work? How do
I compute the CP for a glider?

Glider stability is similar to a rocket stability, but a bit more
complicated. The equivalent to a rocket Center of Pressure (CP) is called
the Neutral Point (NP) of a glider. There is an article on how to calculate
this in the 1980 MIT Journal available from NARTS. Just as a rocket CG needs
to be ahead of the CP, a glider CG must be ahead of its NP for it to be
stable. 10-20% of the wing cord (the distance from the leading edge to
trailing edge of the wing) is a good margin for free flight models. RC
models can get by with much smaller margins.

There are several good articles on Boost Glider Stability in old Model
Rocketry Magazine and Model Rocketeers. Reprints of many of these are
available from NARTS and/or NARTREK.
------------------------------------------
8.2.10 What motor should I use to fly my glider?

Typically, you want a short delay, and a low average thrust for a glider.
For example, a B class model would probably do better with a B4-2 than a
B4-4 or a B6-2. Be careful of motors with large ignition spikes, like the
A10-3 or C5-3, unless you want to re-kit your model. Core burning motors,
including most composite motors are not usually suitable for gliders.
------------------------------------------
8.2.11 This thing looks weird sitting on the pad. How do I launch a glider?

Since the motor is near the front of the glider. there isn't much left of a
3' launch rod once you put a glider on the pad. Frequently the glider will
fall off the pod while sitting on the pad. The other big problem is that
once the motor ignites, the clips fall, and can catch in the wings or stab
of the glider.

The solution to all of these problems is to launch gliders from a "Power
Tower". This is nothing more than a 3' dowel with a launch rod on the top.
Sharpen one end of the dowel, and pound it into the ground. You can drill a
hole for the rod, or just tape it in place. I like to bevel the end of the
dowel at a 45 degree angle. A scrap ceramic tile with a hole drilled near an
edge makes a good blast deflector. Make sure that the exhaust is directed
AWAY from the glider, and not back into the wing! The pod now sits on the
deflector, and the glider hangs below the rod, against the dowel.

To prevent the clips from catching the tail, you can either tape the clip
lead to the dowel, or better yet, use a second launch rod about a foot away
as a gantry, so the clips fall away from the glider. A couple more rods are
handy if it is a bit windy to prevent the glider from blowing off the pod,
or twisting on the pad.

I've gone one step farther, and made a miniature version of a Chad Pad,
using 2 2' pieces of 1x2, a 1/4-20 carriage bolt, and a blind nut (T-nut) in
the end of the 3' dowel. The base of the Chad Pad has extra holes in each
"leg" for extra launch rods to hold the wing and ignition leads.
------------------------------------------
8.2.12 My glider looped and crashed into the ground. What is wrong?

First check for a warp or misalignment in the wing or stab. These are the
most common cause of boost problems, and the reason that accurate building
is so critical. If anything is found, fix it.

Most gliders will have some pitch down at ignition and early boost, and
gradually change to a pitch up condition near burnout. This results in an
"S" shaped flight profile. If the deviation is minor, don't worry about it.
A slight roll during boost will keep your glider headed in the right
direction.

Models that have boost problems can often be helped with a longer and/or
heavier pod. Extending the fuselage to put the motor farther in front of the
wing also helps. A longer rod may help boost also, as will avoiding high
winds when launching.

If the model pitches down severely under thrust, the pylon may be too tall
or the thrust may be misaligned. If the model pitches up under thrust, the
pylon may be too low, or the thrust misaligned. If the model starts
straight, then starts pitching up, the wing lift is causing the problem.
------------------------------------------
8.2.13 My glider shredded. What is wrong?

It was either not strong enough, or the motor was too powerful. If the motor
was too powerful, then the fix is obvious. Use a less powerful motor next
time. Beware of cored motors, they love to shred gliders. This includes the
ignition spike of the C5-3, A10-3, B8, and almost all composites. A few
composites, like the AeroTech/Apogee C4, D3, and E6 are designed for
gliders.

There are several things that can be done to strengthen gliders. Spruce is
often used for the fuselage to increase its strength, but at a significant
weight penalty. Wings can be made of thicker wood, although this increases
the weight of the glider. When trying to maximize performance, it becomes
important to select the density of the balsa used in your glider. Lighter
wood (6#/ft^3) will save weight, while denser balsa (10#/ft^3) is stronger.
Use the lighter wood for wings and stabs, the denser for fuselages, which is
still lighter than spruce.

You also need to consider the grain of the balsa. "A" grain wood has the
grain running perpendicular to the surface. It is very flexible. It is not a
good choice for wings, but is excellent for sheeting built up surfaces, or
rolling balsa tubes. "C" grain wood has the grain running parallel to the
surface. It has a mottled appearance, and is very stiff. It is ideal for
wings and stabs. "B" grain is between A and C, and should be used where
stiffness is not an issue, such as fuselages.

The SIG catalog is an excellent reference on the subject of balsa density
and grain.

Higher aspect ratio wings are weaker than low aspect ratio wings. Try
redesigning your wing or tail to lower the aspect ratio.

An excellent way to strengthen balsa without adding much weight is to tissue
the glider wings. This is an art in itself. You will need some "Jap" tissue
(from SIG or Peck Polymers) and some clear dope. I have found that SIG
Nitrate dope is less likely to warp the wings. The tissue comes in assorted
colors to decorate your model. Use 2 colors, with a darker color on the
bottom, for visibility in the air, and a lighter color on top for visibility
on the ground. Green is a poor choice for the top, but Blue surprisingly
looks pretty dark in the sky. A couple primer coats of dope are applied to
the balsa surfaces. Another coat is used to stick the tissue down to the
balsa. More coats over the tissue soak thru and bond the tissue to the
balsa, and fill in the pores.

Two other ways to make lighter wings particularly on large gliders are built
up construction, and foam cores. A wing can be built of balsa strips, and
covered with tissue. This can yield a very strong but lightweight wing. Foam
is commonly used in RC models, and can be used in some of the larger gliders
(C-D and up) covered with fiberglass or tissue. Uncovered foam from meat
trays can be used for some mini-motor designs. These techniques are beyond
the scope of this FAQ.

The leading edge of a wing is prone to nicks and dings from running into
things. This can be reinforced with a thin strip of spruce, or a thin piece
of nylon or Kevlar line glued along the edge.

For the ultimate in strength and low weight, all parts of a glider can be
reinforced with carbon fiber or Kevlar. This is applied either with Amberoid
or an Epoxy resin.
------------------------------------------
8.2.14 The pod stuck on my boost/glider and the thing crashed. What is wrong?

You've just been shot down by the "Red Baron". If it stuck, try sanding to
loosen things up a bit. Check the action of the pod when deploying.
Streamers or parachutes have a nasty habit of catching on things that you
didn't want them to, like glider wings. Sometimes fastening the recovery
system to the pod in a different manner will fix the problem. Some pod
systems are specifically designed to prevent this problem, Try one of them.

You can also have the opposite problem, where the pod falls off too soon,
sometimes under power. First check the fit. If it is too loose, use tape to
make it tighter. This could also happen at launch, where the glider is blown
off the pod by wind, or just after launch due to a structural failure.
------------------------------------------
8.2.15 My glider glides like the space shuttle (or worse). What is wrong?

Unless you are very good and very lucky, your glider will need several
adjustments before it glides well. The process of making these adjustments
is called trimming. The goal is to get a glider that transitions quickly and
flies smoothly, gently circling overhead. If you are right-handed, you will
probably have best luck trimming your glider to circle to the LEFT. If you
are left handed, reverse all the following references to left and right.

All trimming is done with the model in glide configuration. For a BG, this
means without the pod, For an RG, it means with a spent motor casing
installed, and wing, pod, or whatever deployed as it will be in flight.

The first step in trimming is to locate the CG at the proper position. If
you are lucky, the instructions or plans will tell you where to locate the
CG. If not, you will need to compute the Neutral Point (CP), or use a
typical location like 1/3 of the wing cord from the leading edge. Gliders
are often tail heavy. Add weight to the nose if necessary to get the glider
to balance 10-20% of the wing cord in front of the NP.

All the rest of the trimming should be done by controlled warping of the
flying surfaces. Start by getting the model to glide straight, which is much
easier if it was built without any warps. In an open area gently toss the
glider forward, releasing it with both the wings and fuselage level. Note
its action. If the model dives (drops its nose), warp the stab trailing edge
UP a bit. If the model stalls (noses up, then suddenly drops, often straight
into the ground) warp the trailing edge of the stab DOWN a bit. The best
glide us usually right on the edge of a stall.

I like to warp both wing tip trailing edges up to prevent tip stalls, and the
center portion of each wing down to increase the wing lift.

Then add a left turn until the model has a slow flat circular glide. Some
turn is often added during construction by tilting the wing in the direction
of the desired turn, or tilting the stab in the OPPOSITE direction. Turn can
be increased by warping the trailing edge of the OPPOSITE wing down a bit. I
try to avoid warping the inner wing panel trailing edges up at all, as this
can lead to spiral dives. Turn can also be adjusted with the rudder.

For a left roll on boost, warp the left tip of the stab trailing edge up,
and the right tip down. This works at high speed, but has little effect at
glide speeds. Use wing warp, stab tilt, and a bit of rudder to increase or
decrease the turn as needed.

Try a few harder throws. The glider should quickly settle down into a flat
gentle circle. Continue adjusting the surfaces until you get this result.

Now you are ready for a serious hand launch. This is an art form in itself.
Throw the model up as hard as you can, at a 45 degree angle up and to
your right, and with the wing banked at the same 45 degree angle. The model
should slowly roll to the left, changing from a right turn to a left turn.
If you are lucky, the model will be gently circling 30 or more feet
overhead. If not, it probably smacked the ground, so pick it up and try
again. Go back and check the trim with a gentle toss, and if all is OK, try
again. You may want to vary the angles between 30-60 degrees each, until you
find what works best for you and your model.

Now you are ready for the first launch. Pick a reduced power motor, just
enough to get the glider to a reasonable altitude, and launch it. Use a
power tower as described previously. Carefully observe the boost,
transition, and glide. Watch out for a "death dive" where the glider never
transitions and comes straight down. This can be fixed with increased stab
incidence or warping the trailing edge of the stab up. Also watch for
"spiral dive" where the model turns very tightly and crashes into the
ground. This is caused by too much turn, or a wing that isn't producing
enough lift. Try reducing the turn or warping down the inside edge of the
inboard wing.

Continue to adjust the flying surfaces until you get the flight you want.
Now move up to the desired motor size, and fly again. Soon you'll need to
read the answer to the next question.
------------------------------------------
8.2.16 My glider never came down and flew away. What is wrong?

If it went in a straight line, you need to re-trim the glider to circle as
it glides. Perhaps your field was too small. Find a larger place to fly.

If neither of these is the case, you probably just found a thermal. Air is
not static. It moves around due to uneven heating and cooling. A hawk
circling overhead, without flapping its wings is in a thermal. When air is
heated, it rises. Whatever is in that air goes up with it, be it bird,
rocket, or airplane. If the air is rising faster than the sink rate of your
model, the model will rise in the air. In general, this is good, as it
allows your model to fly much longer. It stops being good when you lose the
model!

This is a "good" problem. it means you've solved most of the problems you've
encountered, and have (had?) a pretty good glider. Picking thermals is an
art that is beyond this FAQ. Now we have to find a way to get the glider
back. These devices are called dethermalizers (DT) because they are designed
to get your model out of a thermal.

This is done by transforming a good glider into a bad glider. There are two
parts to this transformation. The first is some sort of timer, to cause the
action to occur when you choose. The second is an actuating device that
de-stabilizes the glide.

Timers come in several forms. Most common is dethermalizer fuse. This looks
more like cotton rope, and burns very slowly, typically 1/4" per minute. By
having this fuse burn a string or rubber band, we can actuate a device in
flight. Be sure to use a snuffer tube with the fuse, to prevent the fuse
from falling free and starting a grass file. Other more sophisticated timers
are built from small spring wound motors, or a viscous fluid like STP or
silly putty with a piston slowly moving thru the fluid.

There are many actuating devices used. The simplest is a drop weight. Since
we often need to add weight to the nose of a glider when trimming, this
weight can be dropped, with a string going either to the tail or INSIDE wing
(if you go to the outside wing, all you will do is change the glider from a
left turn to a right turn, or vice versa). By shifting the weight, the
glider will now severely stall (tail), or spiral (inside wing) into the
ground.

The "beer can" DT was popular at MIT because of its first step, empty a can
of beer! A piece of the aluminum can is deployed as a flap from the INSIDE
of the fuselage. This acts as a drag break, and causes the glider to slowly
spiral down.

Often a DT consists of a flap, either on the wing or stab, that pops up and
alters the trim of a glider, causing it to spiral dive or stall. One problem
with these is that if not set properly, they can mess up the trim of your
glider, eliminating the need for a DT in the first place.

Another problem with many DTs, especially those that produce a stall or
gentle spiral, is that in a strong thermal, they may be insufficient to
recover the model. Finally, the DT action may bring the glider down so hard
that it is damaged on landing.

I like the pop up wing DT used on the Gold Rush (Model Aviation May 1985
page 64). The entire wing is hinged, and pops up about 60 degrees. This
effectively turns the entire wing into a drag break, sending the fuselage
straight down. The model lands nose first, protecting the delicate tail from
damage. A variation of this totally cuts the wing loose, except for a string
that ties the wing to the tail. The fuselage falls like an arrow, nose
first, with the wing fluttering behind. Another nice feature for the serious
competitor is that the hinge pin can be removed, making the model very easy
to pack for shipping.
------------------------------------------
8.2.17 References: (kits, books, publications, catalogs)

Kits:

Apogee Maxima A
Maxima B
Eclipse ???
Edmonds Deltie
Deltie-C
Deltie Thunder
Ivee
Ivee-C
Estes
#2075 ARV Condor
#2097 Manta
#1284 Space Shuttle
#2086 Tomcat
#2112 TransWing
MRC Thermal Hawk
QCR Auta Sight FWs
Easy Slide RGs
Edmonds Canard RGs
Folded Wing RGs
Never Loop BGs
Dethermalizer kit
Quest #3002 Aurora
#3006 Flat Cat

Plans:

Name Number Source
---- ------ ------
Athena NFFS plans
Bo Weevil NFFS 1973
Catharsis BH-151 Bill Hannah ???
Challenger MA August 1985 page 67
Flip SIG kit
Gold Rush MA May 1985 page 64
Pigeon SIG kit
Polly AMA #263 MA May 1979 page 50
Roll Out AMA #201 MA
Roscoe 18 AMA #509 MA May 1986 page 60
Semi Pro AMA #124 MA January 1976 page 22
Stomper AMA #510 MA May 1986 page 60
Supersweep 22 NFFS 1976, AAM December 1974
Sweepette 18 NFFS 1982
Thermic Jetco kit
Wasp VI AMA #343 MA August 1981 page 57, NFFS 85
Zenith AMA #705 MA December 1991 page 61

Books:

"Flying Hand Launched Gliders" John Kaufmann, William Morrow 1974
(out of print, often found in the children's section of libraries)

"Handbook of Model Rocketry", G Harry Stine, Wiley 1994,

"Hey, kid, ya wanna build and airplane?", Bill Hannan, Model
Builder

"Model Rocket Design and Construction", Tim Van Milligan, Kalmbach
1995 email: 10237...@compuserve.com

"Throw it out of sight" Lawrence Abrams

???, Bill Winter, 1951

Publications:

NARTREK, c/o Lew Proudfoot 310 Dover Court Allen, TX 75002 e-mail
lewis_p...@comsys.rockwell.com or Dr4...@aol.com

NARTS, P.O. Box 1482, Saugus, MA 01906 e-mail
73320...@compuserve.com

NFFS digest, 19 Frederick Dr. Newport News, VA 23601 $15/year

NFFS plans, 10115 Newbold Dr. St. Louis, MO 63137

NFFS publications, 4858 Moorpark Ave. San Jose, CA 95129

Zaic yearbooks, Model Aero Publications, P O Box 135, Northridge, CA
91343

Catalogs:

Apogee Components Inc., 19828 North 43rd Drive, Glendale, AZ 85308
email: 71441...@compuserve.com

Eclipse Components, 570 Buckeye Dr, Colorado Springs, CO 80919
email: 10210...@compuserve.com

Edmonds Aerospace, 13326 Preuit Place, Herndon, VA 22070
email: RobEd...@aol.com

QCR, 7021 Forest View Drive, Springfield, VA 22150

SIG, 401 S Front St, Montezuma, IA 50171 (800)247-5008

Wolfram v.Kiparski

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Rec.Models.Rockets FAQ : PART 09 of 14

COMPETITION AND RECORDS

-----------------------------------------------------------
9.1 Are there any manufacturers making kits specifically designed for competition?

There are several sources of kits designed primarily for competition.
Some of the manufacturers are:

Apogee Components rocket motors 1/4A - F
630 Elkton Drive Micro Motors (10.5mm) 1/4A - B
Colorado Springs, CO 80907-3414 Composite 13mm B motors
t...@apogeerockets.com Long burn D, E, and F motors
(Timothy Van Milligan) Kits and supplies
(719) 535-9335 Educational materials and books
http://www.ApogeeRockets.com Catalog - $2.00, or see website

Eclipse Components Competition model rocket parts
570 Buckeye Dr. Blackshaft (phenolic) tubing
Colorado Springs, CO 80919-1212 inexpensive
(719) 598-6105 Catalog - $1.00
eclip...@worldnet.att.net
(Todd Schneider)

Pratt Hobbies CMR-style nose cones and
2513 Iron Forge Road egg capsules
Herndon, VA 20171 Catalog: FREE
(703) 689-3541 (voice/fax)
76703...@compuserve.com
http://ourworld.compuserve.com/homepages/pratthobbies

Qualified Competition Rockets Offers a wide variety kits for
c/o Kenneth Brown competition rocketry
7021 Forest View Drive piston launchers, tubing, and
Springfield, VA 22150 misc. supplies
Catalog: SASE

-----------------------------------------------------------
9.2 What are the major categories of competition model rocketry?

The NAR sanctions model rocketry contests throughout the USA, and
throughout the year. The contest year runs from July 1 - June 30.
The final contest for a given contest year is NARAM, usually held
in August, after the end of the contest year. The complete list
of event and rules for model rocketry may be found in the NAR
"United States Model Rocket Sporting Code," also known as the 'Pink Book.'
It is available free to NAR members, and may be ordered from NARTS.
Some of the event types are:

- Altitude (1/4A - G)
The purpose is to get the maximum altitude from a model using a
specified class of engine.
- Streamer Duration (1/4A - G)
The purpose is to get the maximum flight duration from a model with a
specified engine type using streamer recovery.
- Parachute Duration (1/4A - C)
The purpose is to get the maximum flight duration from a model using
a specified motor type.
- Eggloft Altitude/Duration (B - G)
In this event the competitor must launch either one to two large raw
hen's eggs, depending on engine type and specific event, and recover
it/them, intact, crack-free. The goal is either to reach the highest
altitude or have the longest duration flight, depending on the event.
- Rocket Glider and Boost Glider Duration (1/4A - G)
In these events the competitor launches a glider using a rocket engine
and tries to achieve the longest flight duration of the glider. In
boost glider the pod containing the motor may be ejected and recovered
separately. In rocket glider all parts, including the expended engine,
must stay with the model. Rocket glider is considered to be the more
difficult event because the model must be both a rocket and a glider
without loosing any parts. The CG and CP requirements for the two
phases of flight are very different. See Part 08 of this FAQ.
- Helicopter Duration (1/4A - G)
In these events the model ascends as a rocket. Rotor arms then extend
by some mechanism and the rocket slowly descends like a helicopter which
has lost power.
- Payload Altitude (A - G)
In these events the competitor must launch one or more standard NAR pay-
loads (1 ounce each of fine sand) and recover the model. The number
of payloads increases with larger engine sizes.
- SuperRoc Altitude/Duration (1/4A - G)
These events are for rockets that have a minimum and maximum length
requirement based on engine class (0.25 - 4.5 meters). There are
both altitude and duration variations. The trick to these events is
that the model may not bend or crimp during flight.
- Scale Events
These are craftsmanship events where competitors build scale models of
real military or commercial rockets. Fine craftsmanship is emphasized.
* Scale: exact replicas of rockets, with major scale dimensions
verified by judges.
* Sport Scale: adherence to scale is judged from a distance of 1 meter.
* Peanut Scale: Sport Scale for small models (<30cm long or <2cm dia.)
* Giant Scale: Sport Scale for large models (>100cm long or >10cm dia.)
* Super Scale: must include a scale launcher as well as model of rocket;
judged same as scale
* Space Systems: Sport Scale model and optional launch complex.
Model must complete a predetermined mission with the purpose of
duplicating in miniature the full-scale operation of the prototype.
- Plastic Model Conversion (PMC)
This event is either loved or hated. Competitors enter plastic models
of rockets or other aero-vehicles that have been converted to fly as
model rockets.
- Precision Events
These include spot landing, random duration, predicted duration,
precision duration, and predicted altitude.
- Drag Race
Multi-round, elimination tournament where contestants gets points for:
* FIRST lift off
* LOWEST altitude
* LAST to land
- Research and Development
A non-flying event where contestants enter results of research projects.
Entries are judged for completeness, contribution to rocketry
knowledge, degree of difficulty, etc.

The Tripoli "Member's Handbook" currently lists one competitive event for
high power models:

- Altitude Records
The purpose is to get your rocket to the highest possible altitude with
a given motor power range. Verify the altitude achieved.

In 1995, Tripoli added official altitude records for F through O powered
consumer rockets. Some Tripoli records are listed later in this section.
-----------------------------------------------------------
9.3 What are some good events to try when first getting into competition? Any
'sage' advice?

From bmcd...@ix.netcom.com (Buzz McDermott):
I just started competition this year. I must have asked 30 experienced
competitors where to start. I got 30 COMPLETELY DIFFERENT ANSWERS!!
They ranged from 'keep it REAL simple' to 'try everything'. Here is
a summary of the most prevalent advice. It seems to have worked for me.

- Competition requires a large stable of rockets, given all the
possible events and engine categories; start with some of the
simpler ones where a single model might be competitive in more
than one event (for example, the same model might be used for 1/2A-A
streamer or parachute duration, another model might be competitive in
any of A - C streamer or chute duration)
- Try single eggloft (B-C, duration or altitude) before trying the
multi-egg categories (such as D or E dual egg).
- Go for a good, qualified flight first; then decide if 'going for
broke' is appropriate on your second flight (this is for multi-
flight events).
- Get a teammate and enter as a team. There are too many models you
need to compete to be able to build all of them your first year.
Entering as a team let's you pool time, talent, experience, and models.
- Don't get discouraged if you aren't immediately competitive.
Remember, the main goal is to enjoy yourself and HAVE SOME FUN.
If you are new at this, you're going to learn A LOT about rocketry by
doing it the fun way.
- KEEP A LOG OF ALL FLIGHTS. RECORD WHAT WORKS AND WHAT DOESN'T.
NOTE YOUR FLIGHT TIMES, ALTITUDES, ETC. Your biggest weapon
in many events is in being able to predict how your models
will perform.
- Make a model preparation checklist for each event (i.e., a detailed,
step-by-step list of everything necessary to prep the model). Use this
list for your first few competitions. Comp models are often prepared
a little differently from sport models. The difference between winning
and losing is often just attention to detail, or lack of it, in the
heat of competition.

From ma...@jupiter.fnbc.com (Mark Bundick)
Note: This is a condensed version of some competition strategies for
individual and team competitors, written by Mark 'Bunny' Bundick and
posted to r.m.r. Check the r.m.r archive server for the complete posting.
The full posting points out that there are many ways to win, and the
following is just what has worked for some individuals.

Some Individual Competition Strategies:

(a) Read the Pink Book. If you don't know the rules for the event,
you can't know how to win and how to improve. Figure out the
scoring for each event, how many flights are allowed, required
number of returned flights, the reasons for disqualification, etc.
Reading the rules will also give you some insights into how the
contest will be run. Start with the general rules then review the
event-specific rules.

(b) Practice for all events where your experience is low. If you
already know how to fly parachute duration (PD), don't waste time
practicing that at your club's sport launch. Instead, suppose you
don't do well in streamer duration (SD). Build a couple different SD
models with different streamers, and fly each of them at least a
couple of times BEFORE the contest. Take a notebook to the field
and write down what happened, or at least write it down after you
get back home. Such notebooks can be the lifeblood of your
competition model and strategy development.

(c) Improve one event a year. At the start of the season, it helps if
you pick one of your weak events for special attention during the
year. Review the existing models and strategies for the event, look
over the competition carefully during the contest year, and practice
this key event each and every sport launch or test flying session
you attend.

(d) Strive for consistent flights. Rob Justis, my old teammate from
the 70's, always reviewed our DQ's after the meet and separated
them into "DQ's for the right reason" i.e no return, and "DQ's for the
wrong reason", i.e. separation. We strove to avoid the latter
obviously. This made us terribly consistent, and with today's "two
flights count" rule, this is even more important.

(e) Fly all the events. Sounds simple, but many people don't do
this. You don't have to win the event, but if you don't fly it, you're
sure to get behind because you're conceding flight points right off
the bat to your competition. Over the course of a contest year,
you can concede 10% of your yearly total this way.

(f) Concentrate on events with high individual event weighing
factors (WF). If you have to choose events to fly, or are short of
preparation time for some of the scheduled events, prepare for and
fly the highest WF events first. Simple again right? But how many
people go to a contest and fly PD first thing in the AM cause the
wind is calm, and ignore BG which has a WF two to three times that
of PD?

(g) Refine, don't abandon, your models and strategies. Rarely do
you get super performance improvements from forgetting all you
know to adopt a totally different strategy. I've seen so many people
hop onto a design when it didn't fit their flying style and then get
burned. They switch because some guy had a super performance
at a contest, so he must have the "Holy Grail" of models. Right
after Tom Beach placed highly at a NARAM with a flexie RG, I saw
lots of folks try them, and crash. Tom had lots of flexie experience
that helped, and when regular BG flyers tried to adopt his style
without the background, BOOM! If you're serious about switching
to a completely different model, say from swing wings to slide wing
rocket gliders, then take the time to practice, practice, practice and
build up the background in the new method. There are no quick
fixes to the winner's circle.

(h) Pick your contests carefully. If you can't fly helicopter duration
(HD) all that well, and the next regional you plan to attend has two
HD events, find another contest! Sometimes, this isn't possible. But
if two contests compete for your participation at the same time,
take the one that has more of your "strong" events.

(i) Casting Your Bread: Share what you've learned with others. A
three time national champion who shall remain nameless positively
stomped every challenger in his sight. But his desire for keeping
secrets and his unwillingness to share left him with few friends, and
after a brief time, he left our hobby, poorer himself and leaving our
hobby poorer for failing to let us learn from him. The benefits of
making new friends and sharing far outweigh any short term
competitive advantage you might think you have from being
secretive. As a quotation I once read went "We have all drunk
from wells we did not dig and been warmed by fires we did not
build." So go ahead. Cast your bread on the waters. You won't be
sorry.

Hope this provides you competition types some food for thought.
I'd love to hear from anyone with comments, questions, brickbats,
etc. at ma...@fnbc.com.
-----------------------------------------------------------
9.4 What is a 'piston' launcher? Does it really help?

From: Roger....@umich.edu (Roger Wilfong)
Pistons offer several advantages and a couple of hassles.

+1) They eliminate the need for launch lugs and therefore reduce drag.
+2) They keep ignition leads from fouling in glider wings.
+3) They can increase lift off velocity (see below).
+4) They recover an otherwise lost portion of the whoosh generator's
impulse.

-1) They require additional maintenance.
-2) Ignition can be a hassle.

A launch piston is usually made of cylinder of 12-18" of BT-5 or PT-13
and a fixed piston made of an old 13mm motor casing or brass tubing.
In practice, the support shaft is attached to a tripod or other launcher,
an igniter is inserted into the tubing on the top of the piston. The
bottom 1/4" of the motor in the model is friction fitted to the top of
the piston tube and lowered onto the igniter (I use 2-3 short pieces of
thin 1/4" masking tape across the joint of the piston/body tube to
reinforce the friction fit - actually I've found it easier to use a
looser fit and the masking tape than to get just the right friction fit).
The micro clips of a launch controller are attached to the bare ends of
the zip cord. When the motor ignites, exhaust gas pressurizes the
cylinder and pushes the piston down. Since the piston is fixed, the
effect is that the cylinder is pushed up. When the stop ring at the
bottom of the cylinder hits the bottom of the head, the cylinder stops
and the model pops off the cylinder.

In effect the piston has acted as the launch lug for the fist 12-18" of
motion.

Roger's Piston Theory (developed through observation and tinkering, it
is not based on a mathematical analysis):

For performance events, pistons offer an advantage over launch lugs or
towers primarily because they convert an otherwise unusable portion of
motors total impulse into motion. There is a startup time at the
beginning of the burn where the motor is not producing enough thrust
to lift the rocket - it is this portion of the burn that the piston is
making use of.

Since the piston gets the model moving before the motor generates enough
thrust to lift the model, it is possible that at the instant of
separation, the motor may no be developing sufficient thrust to keep
accelerating the model and the model may decelerate for the next few
feet after leaving the launcher. This is not a problem for PD/SD models
and most gliders - they are typically light enough that the piston has
accelerated them to a high enough speed for the fins to work properly;
however, it can be a real problem for payloaders and egglofters (I have
seen egglofters almost come to a stand still after leaving a short
piston). So for heavier models, a piston/tower combination provides
additional guidance and helps prevent tip off.

The tower is of only small advantage with SD/PD models; however, it can
help if there are other disturbing forces at separation that could cause
the model to tip.

Because they affect the gas flow during the ignition of the motor, pistons
don't work well with composite motors. My experience has been that
composites either cato or chuff when used with a piston. (If someone
has worked out using a composite on a piston, how did you get it to
work?)

Pistons are a real advantage in any performance event. For eggloft and
payload, they typically allow you to use the next longest delay. For
instance, a B6-2 is needed for a conventional eggloft model. On an 18"
piston, a B6-4 ejects at apogee. Earlier I referred to using a piston
on a Big Bertha - an A8-3 gives a marginal flight without the piston;
with the piston, ejection is at apogee.

There are a couple of variations and modifications to conventional pistons
that can further enhance their performance. The diameter of the head
(6, 13, 18 and 24mm) is one parameter to play with. Jeff Vincent and
Chuck Weiss presented a floating head piston as an R&D project at NARAM-
28 that further increased performance.
-----------------------------------------------------------
9.5 Aside from hanging around 'old timers', how can I learn more about
competition strategies and techniques without re-inventing the wheel
many times over?

The best place to start looking would be the NAR Technical Services
(NARTS) catalog. NARTS has several documents of particular interest to
competitors. The NARTS catalog can be browsed at the NAR web site -
http://www.nar.org/
Look for the NARTS catalog, and when browsing through it, look for these titles:

US Record Setting Designs

CMASS Plan Book

MIT Competition Notebook

Journals of the MIT Rocket Society...

Proceedings of the MIT Model Rocket Conventions...

NAR Technical Reviews, Volumes 1 - 7

Boost Glider Analysis-"A Free Flight Method For Boost Glider Analysis."

Streamer Duration Optimization

Basic Design Rules for Boost and Rocket Gliders

-----------------------------------------------------------
9.6 Tripoli Altitude Records

The following is a list of altitude records based on motor class. These
are all official Tripoli Altitude Records as determined by the Tripoli
Contest and Records Committee. Further information on Tripoli Altitude
Records and specific requirements can be found in the Altitude
Competition portion of the Tripoli Handbook.

Motor Class Altitude Name Date
------------------------------------------------------------

F 1387 meters Mark Clark 3/10/96
G 1483 meters Mark Sims 11/02/96
H 2221 meters Dave "Fritz" Katz 11/05/95
I 3997 meters Pius Morozumi 9/09/95
J 3006 meters Chet Geyer 5/18/96
K (unclaimed)
L (unclaimed)
M (unclaimed)
N 9431 meters Walter Blanca 8/14/95
O (unclaimed)


The above list of official Tripoli Altitude Records is current as of
January 20, 1997.

Robert Gormley, Chairman
Tripoli Contest and Records Committee
-----------------------------------------------------------
9.7 NAR Competition Records

NAR competition records can be viewed using your web browser at:

http://www.nar.org/

-----------------------------------------------------------
9.8 Some Unofficial High Power Altitude Attempts

Some of the high power records come by way of a posting from Chip Wuerz
(d...@engr.ucf.edu). Chip is part of the University of Central Florida's
high altitude rocketry project. Additional information has been taken from
several issues of _Tripolitan_/_High Power Rocketry_ magazine.

* * Some current records for NON-METALLIC NON-PROFESSIONAL Rockets: * *

---Top altitude holders:

Altitude: 27,576 (altitude by Adept altimeter)
Set by: Pius Morozumi
Event: Black Rock V, Black Rock Dry Lakebed
Date: July 16-18, 1993

Altitude: 24,771 feet (11.7% tracking error)
Set by: Chuck Rogers and Corey Kline
Event: Lucerne Dry Lake Bed, Lucerne, Ca.
Date: June 1989, USXRL-89

Altitude: 24,662 (tracking error unknown)
Set by: Tom Binford
Event: LDRS XI, Black Rock Dry Lake Bed, Nevada
Date: August 16, 1992

Altitude: 22,211 feet (5.3% tracking error)
Set by: University of Central Florida
Event: LDRS X, Black Rock Dry Lake Bed, Gerlach, NV.
Date: August 1991


Highest tracked flight at LDRS-X / BALLS 1.
Second all-time highest track of a non-metallic high power rocket.
University of Central Florida's research project and altitude attempt
to break the current high-power rocketry altitude record of 24,771 feet
set by the KLINE/ROGERS team in 1989. Altitude attempt had been based on
3850 NS L-engine, new Vulcan L-750 engines deliver 3,000 (now known to be
less from motor testing results) newton seconds. In an attempt to make
up power loss and to provide margin on the goal altitude of 25,000 feet,
the upper stage was delay-staged by several seconds. Altitude predictions
computer simulation program predicted 28,500 feet. Upper stage flew
substantial trajectory, reaching apogee nearly 2 miles downrange.
Rocket used microprocessors / timer-controlled staging and ejection,
on-board flight data measurement package, and a radio beacon system to
locate upper stage. Track was accomplished using red carpenters chalk.
Both stages were recovered.
-----------------------------------------------------------
9.9 Biggest Non-metallic Rocket Flights

1) Rocket: Down Right Ignorant
Weight: 800 pounds +
Set by: Dennis Lamonthe, Chuck Sackett, and Mike Ward
BlackRock Dry Lake Bed, Gerlach, NV.
August 17, 1992, FireBALLS experimental launch
Description: Super scale based on Esoteric rocket designed by Ron Schultz
Height: 34' 7"
Diameter: 24"
Power: 1 O-class custom motor
5 Energon L1100 motors
8 ISP K1100 motors
(around 76,000 NS total impulse)
Materials: 24" fiberglass tubes for main body tube
1/8" aluminum plates for coupler bases and fin
mounting boxes
1/2" aluminum plate for motor thrust plate
2x5" oak boards for tube coupler assemblies
2x5" pine boards for body tube strengthening
plywood centering rings
3/4" birch fins
14" paper tubing for upper body tube hard resin/fiberglass
nose cone (originally a sounding rocket nose cone shroud)
Note: The definition of 'non-metallic' traditionally has meant
'no substantial metal components' as well as no structural
components being metal. DRI appears to push that definition
to its absolute limit, or a little beyond.
-----------------------------------------------------------
9.10 Other Non-professional Flights of Note

1) Rocket: Frank Kosdon metal rocket
Date: LDRS XII
Argonia, Kansas
15 August 1993
Power: Kosdon non-certified O10000 (that's O-10,000)
Materials: All metal rocket with custom manufactured motor
Altitude: 35,407 feet AGL; closed optical track
Notes: This is a special-case flight. The rocket does not
follow the rules for high power because metallic rockets
are expressly prohibited by both the NAR and Tripoli.
It also uses a custom made motor. The motor was made
by a manufacturer with other high power motors certified
by Tripoli. It was pre-manufactured and solid propellant,
within the total NS limits of high power consumer rockets.

Tripoli does not recognize this flight, or any other flight,
for altitude record purposes unless a successful deployment
of the recovery system is observed or the rocket can be
recovered to show successful recovery system deployment.

-----------------------------------------------------------
9.11 Some other highest verified altitudes

Robert (Bobby) Gormley has gathered the following F through Open (i.e.,
unlimited) altitudes. These are not official records, but the highest
verified altitudes of CONSUMER ROCKETS for each motor class.

From: rgor...@phoenix.Princeton.EDU (Robert Gormley)

Class By Motor(s) Altitude Launch
-----------------------------------------------------------------

O Frank Kosdon O10,000 37,978 feet Fireballs 005
M Univ. Cen. FL L750/L750 22,211 feet LDRS-X
L Pius Morozumi K550/K250 27,576 feet Black Rock V
K *Deb Schultz K250 21,659 feet LDRS-XI
J Mike Keller J125 15,062 feet LDRS-X
I Mark Clark I132 11,873 feet LDRS-X
H Mike Vaughn H125 8,435 feet Fireballs 005

* The K250 has been tested to be in the L range and I am looking for
another entry to replace it.
---------------------------------------
Copyright (c) 1996, 1997, 1998, 1999 Wolfram von Kiparski, editor.

Wolfram v.Kiparski

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Rec.Models.Rockets Frequently Asked Questions: PART 10 of 14

HIGH POWER ROCKETRY

Review: A High Power rocket is a model weighing more than 1500 grams (3.3 lb)
at liftoff, or containing more than 125 grams of propellant (total),
or containing any one motor with more than 62.5 grams of propellant.

-----------------------------------------------------------------
10.1 I'm a successful model rocketeer. What do I need to get into HPR?

When this question was posted to r.m.r a while back, these were the pre-
dominant suggestions and tips:

- Start with E/F/G kits with 29mm motor mounts from LOC or Aerotech.
These should be the easiest to build.
- Read and become familiar with the NAR and/or Tripoli High Power Safety
Code(s).
- Get familiar with and use expendable motors before jumping into
reloadable technology.
- Join a high power club if possible (local NAR section or Tripoli
prefecture).
- Be very careful of the construction differences between model and high
power rockets. You HAVE to build higher power rockets to be more sturdy
than model rockets (see the next question).
- If not already a member, join both the NAR and Tripoli (if you can
afford high power rocketry, you can afford to join and support both
these organizations).
-----------------------------------------------------------------
10.2 What are the major differences between model and high power rockets,
besides size and motors? Are they built differently?

Above and beyond all else, high power rockets are built much stronger
than standard model rockets. This is due to the higher speeds and
acceleration achieved by these models. Some of the construction
differences are:

- High power rockets have stronger, thicker body tubes.
- They have MUCH stronger engine mounts, bonded using epoxy rather
than white or yellow glue.
- Engine mount rings, adapter rings, etc., are typically made from
1/8" or thicker aircraft plywood, fiberglass, or phenolic sheet, rather
than paper or balsa.
- Fins are typically made from plywood, fiberglass, phenolic, or
waferglass, not balsa; Thick balsa fins have been used on H/I powered
models, but they have to be reinforced with fiberglass/epoxy laminate.
- Fins are often mounted into slots in the body tube with Through The Wall
(TTW) mounting. Most common and recommended method is glued TTW and
directly onto the motor tube.
- Parachutes are larger and typically made from some type of fabric
(plastic chutes are not strong enough, usually).
- Heavy elastic shock cords or bungee, tubular nylon, or Kevlar shock line
are used rather than rubber for shock cords, and these are typically
epoxied to the motor mount or a bulkhead.
- Positive motor retention systems (clips, bolts, etc.) are important,
as HPR reload casings start to get pretty expensive.
-----------------------------------------------------------------
10.3 How do I get high power certified?

There are two organizations which may certify you to purchase and use
high power rocket motors. These are the National Association of
Rocketry and the Tripoli Rocketry Association. Note that you must be
a member of the organization to certify for high power with that
organization. Once certified, both organizations recognize the
certification of the other.

As of April, 1996, new NAR certification procedures have gone into
effect.

Current NAR procedures:

- For Level 1 certification (the first step) one must fly an H or I powered
rocket successfully, and have it witnessed by two senior NAR members, one
of which must be high power certified. Fill out the proper form, have it
signed by the witnesses, and send it in to NAR HQ.

NOTE: NFPA 1127 allows an uncertified individual to purchase a single H
or I motor for certification purposes.

- For Level 2 certification (the next step up) one must take and pass a
written exam, and then successfully fly a J/K/L powered rocket.
Questions for the examination come from a pool of questions that are
available for review prior to taking the test at the NAR web site.

- The NAR does not currently certify to Level 3 (M and up).

Tripoli certification procedures are scheduled to change on 1 Sep 1996.
At that time there will be three (3) high power certification levels:

- Level 1, allowing single motor H and I flights. No clusters or staging.
- Level II, allowing up through L motors, staging, clustering and hybrids.
- Level III, unlimited, allowing M power and up.

A written test will be required for Level II certification, in addition to
the certification flight. Level III certification requirements will require
pre-flight approval and review from the Tripoli Advisory Board.
-----------------------------------------------------------------
10.4 What is a 'reloadable' motor. Are they worth the price? Are they legal?

A reloadable rocket motor is a metal cylinder with removable end pieces.
Solid propellant and time delay are purchased separately from the motor
casing, in 'reload kits'. These kits contain all of the expendable,
non-reusable materials for a single flight. The cost of the reload is
significantly less than the cost of an expendable motor (when talking
about F sizes and up). Quite a number of reloadable motors and reload
are now certified by NAR or Tripoli. Refer to the approved motor lists of
each organization to see exactly which motors are currently certified.

YOU MUST BE A CERTIFIED MEMBER OF A QUALIFIED ORGANIZATION TO PURCHASE OR
USE RELOADABLE HIGH POWER MOTORS. See section 3.1.9, below, for
information on becoming certified to use high power reloadable motors.

WARNING: IT IS HIGHLY RECOMMENDED BY r.m.r CONSENSUS THAT YOU DO NOT
ASSEMBLE AND/OR PREP A RELOADABLE-TYPE MOTOR UNTIL JUST PRIOR
TO ITS USE (I.E., ON THE FLYING FIELD). *** UNDER NO
CIRCUMSTANCES SHOULD ASSEMBLED RELOADABLE MOTORS BE STORED WITH
IGNITERS INSTALLED ***
---------------------------------------------------------------
10.5 What are these different 'types' of composite motors I hear about (White
Lightning, Black Jack, Smokey Sam, etc.)?

These are all manufacturers' names for various formulations of 'stuff'
they have added to the propellants to get specific pyrotechnic effects.

Black Jack (Aerotech): low(er) average thrust engine which produces a
dense, dark exhaust to aid in tracking. Also has a distinctive roar.
Note: BJ motors have a slow thrust buildup and long ignition time. Take
care when using this type of motor in a cluster. Also play close
attention to the manufacturer's Maximum Recommended Liftoff Weight
(MRLOW).
Blue Thunder (Aerotech): high level average thrust engines with a bright
violet-blue flame and very little visible exhaust. Designed for high
thrust, high acceleration lift-offs. Ignites quickly. Very fast thrust
build-up.
Firestarter (U.S. Rockets): low impulse composite formulation which
produces large numbers of sparks.
Hellfire (Vulcan): a high thrust motor which produces a bright red
flame.
Smokey Sam (Vulcan): produces a dark exhaust to aid in tracking.
Silver Streak (Rocketflite/MRED): produces a fine shower of white sparks
during boost (these are actually black powder motors). VERY fast
ignition and thrust buildup.
White Lightning (Aerotech): medium average thrust engine producing a
bright white flame and distinctive roar. Ignites quickly. Moderately
quick thrust buildup.
-----------------------------------------------------------------
10.6 What's an FAA waiver? Which rocket flights require one?

An FAA waiver is official permission by the Federal Aviation Administra-
tion allowing the launching of rockets exceeding a certain size. The rules
appear in FAR 101.

A document describing FAR 101 is available at the sunsite archive:
http://sunsite.unc.edu/pub/archives/rec.models.rockets/FAA/FAR101_explained

The following are the relevant sections of FAR 101, regulating the
launching of model and high power rockets.

----------------------- FAR 101 Subpart A--General --------------------

Sec. 101.1 Applicability.

(a) This part prescribes rules governing the operation in the United
States, of the following:
(3) Any unmanned rocket except:
(i) Aerial fireworks displays; and,
(ii) Model rockets:
(a) Using not more than four ounces of propellant;
(b) Using a slow-burning propellant;
(c) Made of paper, wood, or breakable plastic, containing no
substantial metal parts and weighing not more than 16 ounces,
including the propellant;
and
(d) Operated in a manner that does not create a hazard to persons,
property, or other aircraft.

[Doc. No. 1580, 28 FR 6721, June 29, 1963, as amended by Amdt. 101-1, 29 FR
46, Jan. 3, 1964; Amdt. 101-3, 35 FR 8213, May 26, 1970]

Sec. 101.3 Waivers.

No person may conduct operations that require a deviation from this part
except under a certificate of waiver issued by the Administrator.

[Doc. No. 1580, 28 FR 6721, June 29, 1963]

Sec. 101.5 Operations in prohibited or restricted areas.

No person may operate a moored balloon, kite, unmanned rocket, or unmanned
free balloon in a prohibited or restricted area unless he has permission
from the using or controlling agency, as appropriate.

[Amdt. 101-1, 29 FR 46, Jan. 3, 1964]

Sec. 101.7 Hazardous operations.

(a) No person may operate any moored balloon, kite, unmanned rocket, or
unmanned free balloon in a manner that creates a hazard to other
persons, or their property.
(b) No person operating any moored balloon, kite, unmanned rocket, or
unmanned free balloon may allow an object to be dropped therefrom,
if such action creates a hazard to other persons or their property.

(Sec. 6(c), Department of Transportation Act (49 U.S.C. 1655(c)))

[Doc. No. 12800, Amdt. 101-4, 39 FR 22252, June 21, 1974]


--------------- FAR 101, Subpart C--Unmanned Rockets ------------------

Source: Docket No. 1580, 28 FR 6722, June 29, 1963, unless otherwise noted.

Sec. 101.21 Applicability.

This subpart applies to the operation of unmanned rockets. However, a
person operating an unmanned rocket within a restricted area must comply only
with Sec. 101.23(g) and with additional limitations imposed by the using or
controlling agency, as appropriate.


Sec. 101.22 Special provisions for large model rockets.

Persons operating model rockets that use not more than 125 grams of
propellant; that are made of paper, wood, or breakable plastic; that contain
no substantial metal parts, and that weigh not more than 1,500 grams,
including the propellant, need not comply with Sec. 101.23 (b), (c), (g), and
(h), provided:
(a) That person complies with all provisions of Sec. 101.25; and
(b) The operation is not conducted within 5 miles of an airport runway or
other landing area unless the information required in Sec. 101.25
is also provided to the manager of that airport.

[Amdt. 101-6, 59 FR 50393, Oct. 3, 1994]

Sec. 101.23 Operating limitations.

No person may operate an unmanned rocket--
(a) In a manner that creates a collision hazard with other aircraft;
(b) In controlled airspace;
(c) Within five miles of the boundary of any airport;
(d) At any altitude where clouds or obscuring phenomena of more than five-
tenths coverage prevails;
(e) At any altitude where the horizontal visibility is less than five
miles;
(f) Into any cloud;
(g) Within 1,500 feet of any person or property that is not associated with
the operations; or
(h) Between sunset and sunrise.

(Sec. 6(c), Department of Transportation Act (49 U.S.C. 1655(c)))

[Doc. No. 1580, 28 FR 6722, June 29, 1963, as amended by Amdt. 101-4,
39 FR 22252, June 21, 1974]


Sec. 101.25 Notice requirements.

No person may operate an unmanned rocket unless that person gives the
following information to the FAA ATC facility nearest to the place of
intended operation no less than 24 hours prior to and no more than 48 hours
prior to beginning the operation:
(a) The names and addresses of the operators; except when there are
multiple participants at a single event, the name and address of
the person so designated as the event launch coordinator, whose
duties include coordination of the required launch data estimates
and coordinating the launch event;
(b) The estimated number of rockets to be operated;
(c) The estimated size and the estimated weight of each rocket; and
(d) The estimated highest altitude or flight level to which each rocket
will be operated.
(e) The location of the operation.
(f) The date, time, and duration of the operation.
(g) Any other pertinent information requested by the ATC facility.

[Doc. No. 1580, 28 FR 6722, June 29, 1963, as amended by Amdt. 101-6, 59 FR
50393, Oct. 3, 1994]


-----------------------------------------------------------------
10.7 OK. I want to fly some high power rockets. How do I get an FAA waiver?

A downloadable, printable copy of
Form 7711-2, Application for Certificate of Waiver, is available at:

http://www.faa.gov/avr/afs/Waiver.htm

From: js...@edison.rc.rit.edu (J A Stephen Viggiano)
I'd like to share with those interested what is involved in applying for
an FAA Waiver. It's not a particularly difficult procedure, and the
FAA personnel I have dealt with are courteous, professional, and
helpful. Don't be scared of the bureaucratic red tape, there isn't a
whole lot of it.

You can get the forms from the Flight Standards District Office (the "Fizz-
Doe") at any airport with air traffic control. Phone the tower and ask
for Flight Standards. Tell them you're interested in launching rockets,
and need an Application for Waiver, FAA Form 7711-2. They should know what
you want. While you've got them on the phone, ask for the address of the
Regional office. You will probably have to file your application with them,
so it will help to know where it has to go!

Now, you take a field trip. Get in your car, and drive to the airport. Not
the passenger terminal, the part where all the private general aviation
planes are parked. There should be a place there for pilots to pay for
fuel, buy toothbrushes and other sundry items, including section maps.
Ask them for the map which includes your launch site. If you're not near
a section boundary, it should be the same map which includes the airport.
(It will also be the most popular map there, and they may be out of
stock.)-: We're covered by the Detroit section map, for example. Never
mind that it's a few states away, and New York is closer, that's just
the way they carve things up. It costs about $3, and it's fun to look at
and try to decipher.

Locate your launch site on the section map. Are there any airports
within 5 miles? If so, you'll need a waiver of Section 101.23(c), which
addresses your proximity to an airport, in addition to waiver of Section
101.23(b), which covers controlled airspace. You type these section
numbers on line 4 of the application. Lines 1, 2, and 3 are your name,
address, telephone number, and all that David Copperfield crap, as
Salinger called it.

Line 5 asks for a detailed description of what you want to do. I usually
put something like the following:

Normal operations of Model and High Impulse Rockets
weighing more than 16 ounces (but less than 80 ounces)
in accordance with the National Association of Rocketry
Safety Codes (please see attached).

Line 6 asks for the location. If you've got the latitude and longitude
to the second, use them. Otherwise, you can refer to a copy of the portion
section map, like this:

On the grounds of and directly above the National Warplane
Museum, Geneseo, NY (please see attached portion of Detroit
section map).

You can then copy that portion of the section map, circle the launch site
in red or some other color, and write the legend, "Area of Proposed
Operations." (Remember, these folks talk in Bureaucratese.)

In either case, this is the line on which you request altitude. Again,
in FAA patois, "No operation under this waiver will exceed 5000 feet AGL"
are the magic words which have worked for us (along with "please" and
"thank you"). If you can read the altitude of the terrain on the section
map, you can add this to the requested altitude above ground level to
arrive at the altitude above Mean Sea Level (MSL), which might be
appreciated by the person processing your application.

On Line 7 you give your starting and ending dates and times, and any
rain dates. It's not necessary (nor is it desirable) to use Zulu
(Greenwich Mean) Time, but these folks use that "hundred hour" jazz
that Colonel Blake on M*A*S*H hated so much. Make sure to indicate
what time zone you're referencing, for example "1030 EDT".

Lines 8 through 14 pertain to airshows and the like, so just put an
"N/A" or two there to let them know these areas aren't blank because of
an omission. You sign on Line 15, and have an opportunity to say a
little something about how you're going to be running things. I usually
write in the following, under "Remarks":

All operations will be conducted in accordance with the NAR
Safety Codes and shall be under the control of an experienced
Range Safety / Launch Control Officer. A spotter will watch
for aircraft entering the operations area, and will temporarily
suspend operations in this contingency.

Make three copies. Keep one for yourself, send your original and two of
the copies to the Regional Office. Attach three copies of both Safety
Codes, because the Model Rocket Safety Code covers rockets which will
be under the terms of the waiver. Also attach three copies of the
germane portion of the section map, if that's how you're indicating
where you are going to fly. Include a short letter of transmittal.

After having some scares about the last two applications I sent in,
next time I plan to include a receipt postcard. I'm going to put my
address on the address side, and on the other side it will say:

Received _________________ (date) an Application for
Certificate of Waiver or Authorization, FAA Form
7711-2, at this office. For further information,
please contact ___________________ (name) at
_________________ (telephone number, extension).

Bureaucrats see these things all the time, and they know what to do with
them.

Mail off this packet to the FAA Regional Office, to the attention of
Flight Standards (I think!). You need to apply at least 30 days (the form
says 45 days, so be sure) in advance. If you don't hear back from them
in two or three weeks, give them a call. We had to do this twice; once the
form was lost, and another time it was just in the "in" basket.

If all goes according to plan, you should get back your application, all
the other stuff you sent (talk about carrying coals to Newcastle!), and
the Magic Certificate of Waiver! There will be a few strings attached.
You should be instructed to inform the nearest ATC, and possibly an
Automated Flight Information Service, a certain time before you start,
in order to "activate" your waiver. You'll probably be instructed to
contact them when you're done, too. Usually these things are not a big
deal, but sometimes you get a person who doesn't know why you're
bothering them. Just tell them that you're carrying out instructions
from the Regional Office to give a Notice to Airmen, pursuant to the
terms of your Certificate of Waiver. A little official-sounding talk
will make them feel right at home.

Of course, you have to make sure all fliers are familiar with the terms
and conditions of your waiver, because it's your butt that's on the
line, too. It is a standing MARS policy that the waiver certificate
and application are available for inspection by all fliers.

After the launch, I usually send a letter to the person who sent me
the Certificate of Waiver, thanking them for their help, and letting
them know we had a safe and enjoyable time. It helps grease the skids
for the next waiver you want, besides being common courtesy.

It's not hard to obtain a waiver if you make your application in a
professional manner, and conduct your activities likewise. There's no
fee, but there is some effort involved. Finally, keep in mind that the
people working on your application are people, and as such they
respond to being treated courteously and professionally. I hope you
find the process relatively simple and painless.

-----------------------------------------------------------------
10.8 Is high power rocketry legal in every state, if the proper forms are
obtained?

No. Even with an FAA waiver, HPR is NOT legal in every state. Check
with your local fire marshal for requirements/restrictions in your area.
The NAR and Tripoli are actively working to get state restrictions on
model and HPR removed.
-----------------------------------------------------------------
10.9 Where do I find out the proper way to use HPR rockets and motors? I'm
familiar with the NAR Model Rocketry Sporting Code. Is there an HPR
equivalent?

Both the NAR and Tripoli have HPR safety codes. The two organizations
are working together to produce a consistent safety code to be presented
to the NFPA. These codes specify minimum launch field sizes, minimum
distance to keep from launchers, etc. The NAR High Power Rocket
Safety Code has been published in Sport Rocketry, and is on their web site.
The Tripoli safety code is published in their Members handbook, which is
sent to all new Tripoli members.
EVERYONE WANTING TO GET INVOLVED IN HPR IS STRONGLY URGED TO JOIN ONE OR
BOTH OF THESE ORGANIZATIONS. There are legal restrictions to buying
high power motors. Only certified members of 'legally qualified'
organizations may purchase them. If you want to fly high power you need
to be a member of either the NAR or Tripoli.

The High Power Safety Codes for both the NAR and Tripoli are based on the
NFPA 1127 guidelines. Both organizations recognize the others safety
code, motor certifications, and HPR user certifications.
-----------------------------------------------------------------
10.10 What are some good kits to build when first getting into high power
rocketry (assuming I have all of the basic model rocketry skills)?

Popular rec.models.rockets vote:
LOC Graduator

From: c...@pdp.sw.stratus.com (C. D. Tavares)

AAA Penn. Crude

From: kapl...@hccompare.com (Bob Kaplow)
- Avoid any kit with plastic fins or internal parts.
- Avoid phenolic tubes, thick cardboard tubes are more familiar
and easy to work with
- For Large Model Rockets, try a LOC Graduator or Rocket R&D/THOY
Hornet
- For a High Power rocket try a LOC IV or EZI-65, or a Rocket R&D/THOY
Falcon

From: JCook@Epoch.C (Jim Cook):
LOC kits are a good introduction into high power - they are strong
(banging it several times for emphasis on the table).

From: buz...@netcom.com (Buzz McDermott)
If you have never flown anything bigger than an Estes or FSI D
motor, I would recommend building one or more E-G kits before
tackling H power and up. When you go for your NAR or TRA
certification, choose a rocket where G and H motors are the low
end or mid-range power options. Going with a rocket where your
chosen motor is at the high end or above the rockets recommended
power range is more likely to fail by over-stressing the design.
Bigger, slower high power rockets are less stressed and more likely to
succeed. In the case of NAR certification, this gets you a rocket
good for multiple certification levels. I like the following (any
are good NAR or TRA certification rockets):
LOC Mini Magg, 38mm mount (G-I motors)
LOC EZI-65, 54mm mount (G-I motors)
THOY (Rocket R&D) Falcon, 54mm mount (H-J motors)

From: mike_...@cjnetworks.com (Mike Forman)
I bought, built, flew and certified on a PML Io. Very nice kit. I
glassed the tube, and would bet it's as close to bulletproof as you
could get and still be legal to fly as a hpr. I posted a review of
the Io here, and you could probably go to dejanews' archive and
retrieve it. Great rocket, great flights, easy to build.

From: ma...@netins.net (Mark U.)
My favorite 4 in. rocket is the THOY/R&D Falcon. In stock configure it
easyily will handle H-J and if beefed up a K is not out of the question.
My second choice would be a PML Quasar this will fly nicely on a H-I
motors.

-----------------------------------------------------------------
10.11 When is a Federal Low Explosives Permit required?

NOTE: As of 1997, the BATF will be formally clarifying their
interpretation of what high power rocket motors require a Federal
Low Explosives Users Permit (LEUP). At the time that this is written
(Jan. 9, 1997) it appears that reloadable motor propellant segments
less than 62.5 grams in mass will require a LEUP if their intended use
is to assemble a motor that has more than 62.5 grams of propellant.
Furthermore, LEUP fees may be raised. At the time of this writing, these
changes are not yet in effect. The National Association of Rocketry and
Tripoli Rocketry Association are working together to see what can be done
to protect the interests of high power rocketry enthusiasts, and will
be keeping their members informed of the latest developments.

The following are excerpts from a joint communique issued by the
High Power Rocket Manufacturers and Dealers Association and the Tripoli
Rocketry Association to the high-power rocket community on 25 April 1994.
It was posted to CompuServe by Michael Platt, president of the HPRMDA.

----
[Based on informal clarification from the BATF, it is our belief that:]

(a) single-use model rocket motors containing no more than 62.5 grams of
propellant are exempt from Federal licensing and storage requirements;

(b) reloadable rocket motor products are also exempt from Federal licensing
and storage requirements, provided that the mass of each propellant grain
is no more than 62.5 grams, and has received a DOT shipping designation
as Explosive 1.4, but may not be made available to children;

(c) any single-use motor containing propellant mass greater than 62.5 grams,
or any reloadable rocket motor product containing a propellant grain
which weighs more than 62.5 grams, is subject to Federal licensing and
storage requirements.

Users (e.g. consumers, flyers) of high-power rocket motors and reload kits
as described in item (c) above, are subject to Federal, and possibly state
and local, permit requirements for the purchase and storage of explosives.
On the Federal level, this involves obtaining an explosive user permit from
BATF, at a cost of $20 for the first year, and $10 for each subsequent
three-year period. An important exception to the Federal requirement for a
user permit is if the user were to purchase a motor or reload kit in his
state of residence as defined by BATF, and either (a) use the motor or
reload kit at the site of purchase (e.g. a launch), or (b) transport it to
an approved storage facility located within the boundaries of said state.

Everyone--manufacturers, dealers (distributors), users--who stores (as
defined by the BATF) a high-power rocket motor or reload kit as described
in item (c) above is subject to Federal, and possibly state and local,
requirements for the storage of explosives. All storage of a high-power
rocket motor or reload kit must be in accordance with Federal explosive
storage requirements, even if a Federal license/permit is not required for
purchase. There are no exceptions to this rule.
-----


A document with questions and answers about the BATF and rocketry is
available at the sunsite archive:

http://sunsite.unc.edu/pub/archives/rec.models.rockets/BATF/batfqa.txt

Instructions for filling out a LEUP are available on the Rocket Science
web site:

http://www.scsn.net/users/rockets/LEUP_consumer.html
-----------------------------------------------------------------
10.12 How do I get an LEUP? Are there any requirements?

The following is an excerpt from the June 1994 'Tripoli Report'. Since
this deals with Federal Law and not Tripoli rules, I do not believe that
there is any violation of Tripoli by-laws in doing this.

Q: How would a person qualify for a Federal user's permit?
A: The chief, firearms and explosives licensing center, will approve a
properly completed application if the applicant:

1) Is 21 years of age or older,
2) Is not a person to whom distribution of an affected high-power
rocket commodity is prohibited under the Act (Federal law),
3) Has not willfully violated any provisions of the Act,
4) Has not knowingly withheld any information or has not made any false
or fictitious statement intended or likely to deceive concerning the
application,
5) Has storage for the class (low explosive) of an affected high-power
rocket commodity, as described on the application, unless he establishes
that his operations to be conducted will not require the storage of an
affected high-power rocket commodity.
6) Is familiar with and understands all published state laws and local
ordinances relating to affected high-power rocket communications
in which he intends to conduct operations.
ATF Form 5400.13/5400.16 must be filed to obtain a permit.

From: buz...@netcom.com (Buzz McDermott)
You may obtain a users permit with or without a storage magazine. If
your primary reason for the permit is to be able to buy HPR motors
at out of state launches, then you don't need a home storage magazine.
If you do have a home storage magazine, remember to keep the proper
records for all motors added to and removed from the magazine.

Michael Platt has indicated willingness to help anyone who has any
questions regarding the proper filling out of the permits. He may
be reached at 7023...@CompuServe.COM.
-----------------------------------------------------------------
10.13 How is thermalite affected by the ATF regulatory enforcement?

From: 7023...@CompuServe.COM (Michael Platt )
Thermalite is a brand name for igniter cord. Purchase and storage of
igniter cord is regulated by BATF. Purchase and/or storage of igniter
cord, IN ANY QUANTITY, requires an explosive license and an approved
storage facility, i.e. an explosive magazine. This includes thermalite
in any length, including the one inch lengths commonly included with
motors produced by various manufacturers. The only exception to this
would be the purchase by a user for immediate use in the state where
he/she resides.
-----------------------------------------------------------------
10.14 How can I get the Orange Book (explaining the ATF explosive laws
and regulations) and the proper LEUP forms?

Call you regional BATF office and ask for the Orange Book and an
application for a Federal Low Explosives Users Permit. Remember that you
want a Users permit (there are several other types of permits). The
regional office will mail these to you at no charge. The documentation
you receive will indicate where the filled in forms and payment should
be remitted.
-----------------------------------------------------------------
10.15 Just what is a 'hybrid' rocket motor? Who makes them?

From: kevin...@aol.com (Kevin Reed)
A hybrid motor as sold for model rocketry uses a solid fuel grain and a
liquid oxidizer -- in the case of commercial model motors, nitrous oxide.
A composite motor uses a solid oxidizer -- ammonium perchlorate -- mixed
with a rubber binder/fuel to make a unified solid grain.

I can't think of any 24mm hybrids on the market; the smallest, I think,
has an "I" rating and fits into a 54mm mount.

There are two companies currently manufacturing them commercially,
Aerotech and Hypertek. One system loads the oxidizer tank before loading
the motor in the rocket, while the other fills the tank after the rocket
is in launch position.

Hybrids have a couple of advantages over composites: one is that there is
virtually no fire hazard transporting or storing the motor: without the
oxidizer in direct contact with it, the fuel grain is almost inert. It is
also not covered by the same DOT shipping restrictions, because the tanks
are DOT certified and the fuel grain poses no environmental or fire
hazard.

[Editor's note: The Jan 1996 issue of High Power Rocketry magazine has an
excellent article comparing the Hypertek and Aerotech hybrid systems.]
---------------------------------------
Copyright (c) 1996 Wolfram von Kiparski, editor.

Wolfram v.Kiparski

unread,
Sep 26, 2000, 3:00:00 AM9/26/00
to
Archive-name: model-rockets/HPR-construction
Rec-models-rockets-archive-name: rockets-faq/part11
Posting-Frequency: monthly
Last-modified: 1997 January 9
URL: http://dtm-corp.com/~sven/rockets/rmrfaq.toc.html


rec.models.rockets Frequently Asked Questions: PART 11 of 14

HIGH POWER CONSTRUCTION TECHNIQUES

This section includes tips and suggestions on various topics having to do

with construction and finishing techniques for High Power rockets. Many of
the same techniques may be used with Large Model Rockets, as well.
Readers are encouraged to read the North Coast Rocketry technical reports
on HPR construction and finishing techniques (available from NARTS and
other sources).

[Note: This portion of the FAQ is maintained by Jerry Irvine
(jjir...@cyberg8t.com).
All comments and suggestions should be sent to him.]

------------------------------------------------------------
11.1 Do you have any tips for cutting and sealing fins used on HPR rockets?

From: utid...@remarque.berkeley.edu (David M.V. Utidjian):

To fill the grain in balsa fins and fill in the spirals in body tubes
use epoxy. I use HOBBYPOXY "Smooth 'n' Easy" Epoxy finishing resin.
For fins it does the trick in one coat... and sands easily... and
adds strength to the fins. I use those disposable brushes with the
metal handles and brush on a single coat after a preliminary sanding.
I then use auto body primer filler in gray and red-brown from spray
cans for the entire model. This gives very thin and even coats. I
alternate the colors of the coats to show where the low and high spots
are. My last sanding before paint is done with 400 grit wet/dry paper
and I do this wet... being careful not to get any inside the body tube.
[Another good coating-type epoxy is PIC 'Coating Poxy'...Buzz]
[NOTE: This is not for kids or the inexperienced!! This technique is
used in HPR where the added weight is not a penalty: Buzz]

From Bob Turner (NAR member, not on net):
Bob Turner (the DARS NAR section advisor) suggests using alcohol in
smoothing 'coating' type epoxies. The PIC 'Coating Poxy' instructions
suggest using your fingers to 'burnish' any surfaces (i.e., fins) filled
with the coating epoxy. Bob suggests using a VERY soft cloth which has
been dipped in alcohol to rub the fins after about 30 minutes (or
whenever the epoxy starts to set and is just slightly sticky to the
touch). [I followed Bob's suggestion and got MUCH smoother fins over
the hand/finger burnishing method...Buzz]

From: ja...@rml.com (Jack Hagerty):
When sanding fins, or any other balsa part that you want to be all
uniform, stack the parts together, even them up the best you can
(you'll be surprised at how uneven those die-cut pieces are!) on
the root edge and drive a couple of straight pins through them to
hold the stack in registration while sanding. For larger fins,
anything over about 2 sq. in, use three pins. I find that the pins
that come in shirts are just about the right size. The small holes
that are left when you remove the pins are easily filled during the
sealing/filling step.

From: kapl...@hccompare.com (Bob Kaplow)
I've found two handy tools for sanding big rockets. 3M makes these
sponge-like sanding pads. They are great for conforming to the
curves of tubes, nose cones, fillets, etc., and make quick work of
fillers. The second is a palm sander, just like Norm uses on TV. Big
rockets call for heavy duty solutions. Save the belt sander for
airfoiling the fins during construction.

Condensed thread on filleting fins; many contributors:
First, ALWAYS fillet high power fin joints, even fins mounted TTW to
the motor mount. This will add strength and improve the aerodynamics
of the model. The suggestions for filleting material include:
* 5 - 30 minute thick epoxies
* 30 minute (or longer) thin epoxy mixed with micro-balloons
until it has a thick, paste-like consistency; let it thicken
some prior to using it
* SIG Epoxilite (warning: this got very mixed reviews)

Always keep a bottle of rubbing alcohol handy when working with epoxy.
Dip your finger in the alcohol and run it along the fillet to smooth
out the bumps. It was mentioned that a pure epoxy 'topcoat' was
necessary on top of the epoxy/micro balloon mixture, although using
an alcohol-soaked finger to smooth the micro-balloons might eliminate
the topcoat requirement.

Use 30 minute epoxy with microballoons added. Let it sit for a few
minutes in the pot so it thickens, and then apply it. The microballoons
make it much less runny, so you don't have to keep watching the fillet
to make sure it's not dripping or running around the edges. Also do one
side of two fins at a time:
\ /
\ / f = fillet, ^ = really bad version of body tube
\f f/ / and \ = fins
^^^^^^
------------------------------------------------------------
11.2 How do you keep in a high power motor in its mount, but still allow
for the numerous lengths in which HPR motors are sold?

From: bi...@hpcvaac.cv.hp.com (Bill Nelson)
I make a clip similar to the ones used on model rockets - however, I do
not pierce the motor mount tube - I place the front end of the retainer
over the front of the tube. It is epoxied/taped in place, just like with
a model rocket. I do not rely on spring pressure to hold the clip over
the end of the engine. I use several turns of strapping tape - wrapped
around the engine or motor mount and the retainer clip. So far, I have
never had a problem with an ejected engine.

From: JC...@Epoch.COM (Jim Cook)
Some folks at NARAM 33 suggested drilling a small hole in the side of
the flange of the rear nozzle retaining ring [of an ISP reloadable motor
casing] to tie the casing to the model. Some might claim this to be
"modification of rocket motors not approved by the mfg." I had though I
heard Aerotech was going to start doing this themselves, but I haven't
seen anything yet.

From: ne...@boi.hp.com (Neil Pyke)
I've built #8-32 "t-nuts" into my last couple of rockets and then made
sheet metal brackets to hold the motor in. I drill two holes, 180
degrees apart, in the aft centering ring and then press and glue the
t-nut into the hole. The screw holds the bracket to the centering ring
and I bend the bracket so it hooks over the end of the motor. The t-nut
works great but I've made my brackets too wimpy. Those that saw
me wandering around just past the flight line at LDRS a couple weeks
ago, looking for my ejected motor, will know that I have not perfected
my application of this design.

From: Roger....@umich.edu (A. Roger Wilfong)
I've used a similar technique with t-nuts and had no problems - yet.
I've also tried a coarse thread sheet metal type screw (I'm not sure
what they're really called - the threading is about twice as coarse as
a regular sheet metal screw) screwed into the rear centering ring at
three locations. The centering ring needs to be plywood and you need to
carefully drill the correct sized pilot hole for the screw. After
'tapping' the screw into the hole, I took it out and ran a small amount
of thin CA into the hole for reinforcement - let the CA set before you
put the screw back in the hole or you won't get it out again. This has
worked on RMS-29 and while it is not as strong as the T-nuts, so far it
has been more reliable than masking tape.

From: soc...@vx.cis.umn.edu (Tim Harincar)
On the 2 29mm birds I've constructed, I use a clip and a thrust ring.
It works like this:


---:| |
=====:| |====== <- Centering Ring
:| |
:| | <- motor tube
:| |
:| | --:
:| | : <-Clip made from steel rod
=====:| |====== :--
:
:--

The steel rod has two opposite 90 degree bends, and is run through the
centerings and along the motor tube. The idea is to spread the force of
ejecting along the top centering ring and to the rest of the motor
mount, instead of making the clip do the work. Also, on larger tubes,
you can design this so that the clip swivels into place, instead of
using spring tension.

The clip then extends 1/4" to 1/2" beyond the end of the tube. You then
use this space for the motor thrust ring. The thrust ring is then added
to the end of motor. I just usually wind the end of my motor with a
bunch of turns of masking tape, but I've heard of people epoxying some
other type of ring to the end of the motor.

From: wa...@netcom.com (Walt Rosenberg)
You use a "thrust ring" - several wraps of masking tape on the nozzle
end of the motor. This prevents the motor from going up the mount.

Of course, if you use re-loadables (ISP, AeroTech), the nozzle enclosure
is larger than the O.D. of the motor mount - in this case, just the tape
to keep it from coming out. Of course there are several methods used to
keep the motor from kicking - screws and washers, screws and hooks,
retaining rings, etc. placed over the ridge on the nozzle end of the
motor.

From: pste...@well.sf.ca.us (Paul J. Ste. Marie)
Typically what you do is wind a ring of masking tape at the end of the
whoosh generator of the same thickness as the engine mount tube.
This serves as a block to keep the engine from sliding up into the
rocket under thrust. Typical widths of tape to use are:

.25" 1/4A-B
.5" C-E
.75" F-H
1.0" H-I
1.5" I-J
2.0" J-K

From: wa...@netcom.com (Walt Rosenberg)
[Referring to the use of different tape widths, above]
1.5" for I-J and 2.0" for J-K may be too wide. You are now going to move
the center of gravity further back. You may introduce instability. I've
never used more than 3/4" for all my high power launches (H-K).

From: kapl...@hccompare.com (Bob Kaplow)
My [retainer] hooks look like this:

----
| | <<- this end slips over lip of bottom reload
| closure
|
|
|
____| <<- this end screwed/bolted onto rear bulkhead

^hole drilled here for cap screw

The top of the hook wraps over and around the reload closure lip, and
can't push out like an Estes clip. Hooks ARE brass. I use stainless cap
screws to hold the clips in place - cap screws stay on the end of the
tool, unlike other screws. I use T-nuts installed on the back side of
the
rear centering ring, or threaded brass inserts to retro-fit older
rockets.
------------------------------------------------------------
11.3 Custom Decals for High Power Rockets

The techniques described here could also be used for model rockets. The
decals made this way tend to be large and `thick', so this info has been
included in the High Power section.

From soc...@vx.cis.umn.edu (Tim Harincar):
As a computer graphics person, I have done quite a bit of experimenting
with laser printers and making my own rocket art. I mostly stick with
clear sticky-back type stocks, they are the cheapest and most available.

I use Fasson brand, and I think its 1.5 or 2 mil. thick. It works
good for
large models but is a little thick for small scale stuff. It curls right
out of the laser while it cools. Don't worry, though. It doesn't distort.
This stuff is typically available at most quick print shops. Typically
its called Crack 'N Peel.

Toner chips very easily off of the smooth finish, so be careful and as
soon as you can, spray on an over coat of clear flat enamel or lacquer.
I tape the sheet down to cardboard then spray, Leave it for a day or so.
This also makes it lie flat.

I know that blank water transfer stock is available, but its about $3 for
an 8.5 x 11 sheet. Use same method as above to preserve the image. This
is usually available at model railroad shops.

I have never seen the dry-transfer stuff, but I know its pretty popular
with the railroad folks. (that is, the pre-printed stuff).

One other option that I have wanted to try is the heat-transfer colors.
Once you have a laser image, you lay a piece of special colored film
over the image and heat either with an iron or re-run the sheet through
the laser and let the fuser do the work. The color then attaches to the
toner.

Most of these colors are metallic, but there are some standard, non-
metallic colors as well. Letraset was the first company to market
the color transfer stuff.

------------------------------------------------------------
11.4 I've had several rocket body tubes ruined by the shock cord tearing
into the body tube at ejection and making long slits. How can I
prevent this?

Many of us have recovered our rockets only to find that shock line has
slit ('zippered') the body tube. This happens most often when a very
thin shock line is used or when the rocket is traveling very fast when the
tubes separate. The following suggestions have been offered to prevent
this from happening:

From: bar...@powder.add.itg.ti.com (Stu Barrett)
I built a LOC Caliber a year or so ago. I installed a LOC ejection
baffle at the top of the motor mount tube and that worked great.
However, I'm in the process of enhancing my model so that it uses the
"anti-zipper" technique that is described in the Mar/Apr [1993] issue
of HPRM. It combines a fool proof mechanism to eliminate the dreaded
"zipper effect" and also has a nice effect that no wadding is needed.
------------------------------------------------------------
11.5 Estes 'toilet paper' recovery wadding strikes me as a bit wrong for HPR
rockets. What are some alternatives?

From: ja...@rml.com (Jack Hagerty)
Just go down to your local building supply store and get a bale of
cellulose wall insulation. This is just shredded newspaper treated in
the same fire suppressant [as Estes recovery wadding]. A $5 bag will give
you enough wadding to last years!

From: js...@rc.rit.edu (J A Stephen Viggiano)

In order to avoid fallout, you might want to put the engine in *before*
the [cellulose] wadding, or, for smaller rockets, a sheet or two of
regular
wadding underneath the fluffy stuff.

Wayne Anthony uses cabbage leaves (you get more leaves per head [than
lettuce], and they seem to be a little tougher than lettuce), and I've
heard of people using grass.

From: buz...@netcom.com (Buzz McDermott)
I use acoustic speaker insulation. I costs #3 - $5 per bag at Radio
Shack. It's reusable, and one bag generally lasts me for dozens of
flights. [Editors note: This material is not necessarily bio-degradable
or environment friendly. Do not use this type of recovery wadding at any
field where remnants might be ingested by live animals. It will kill
them. Also, consider tethering fiberglass to shock line to prevent
loss.]
------------------------------------------------------------
11.6 What are the differences between the various HPR body tube materials
used by the most HPR manufacturers?

The most common one is that material used by Estes and later by other
suppliers such as U.S. Rockets, LOC Precision, AeroTech, Launch Pad, etc.
This material is a spiral wound virgin kraft tube. Virgin kraft is stiffer
than recycled kraft and can much more easily withstand flight stresses at a
given thickness than recycled tubes as commonly found in household goods.

This material typically has an outer wrapper of "glassine" which makes the
tube smooth and accepts paint more easily. It also covers up the thicker
tube spirals of the under layers and makes removing tube spirals with a
couple applications of sanding sealer practical.

Another common tube material is that used primarily by Public Missles. It
is a spiral wound paper with phenolic resin impregnated into it. This has
several advantages such as higher ultimate strength in aero-applications,
more waterproof out of the box and being fairly stiff. However this
material is also susceptible to cracking due to impacts and has been known
to crack during routine slow landings under over adequate parachutes.

A really good material for HPR is used only by Dynacom and U.S. Rockets and
is known as G-10 fiberglass. There are several practical variants of this
material. One can use either cloth wound or filament wound and the G-10
refers to one supplier's particular classification of a resin they use.
Even they use a dozen different resins. Among the glasses uses are
"e-glass" and "s-glass". Since one is both more expensive and stronger in
ultimate fail tests it is often used as motor casing material. However for
airframe applications, cheaper and thinner is better.

Other good but less common materials include cloth wound phenolic
impregnated, paper convolute wound phenolic impregnated, exotic composites
of kevlar, graphite, etc.

A very common material used (at one's own peril) is recycled paper style
tubes such as mailing tubes, paper towel rolls, etc. These must be over
1/8" thick to even be used for HPR at all. Even then they are easy to
damage and "unroll" on landing as they typically do not use glue except on
the edges. Rocket specific tubes are glued across the entire surface of
the superior virgin kraft material.

Plastic tubes can be used but the bonding problems of motor mounts and fins
have resulted in these having virtually no adoption among serious model or
high power rocketeers. Motor mount tubes must have an insulating element
as plastic motor tubes would quickly become the permanent owner of a motor
casing.

------------------------------------------------------------
11.7 How can I strengthen my thick paper (i.e., LOC type) body tubes?

Various composite construction techniques may be employed to strengthen
paper body tubes. These same techniques may be used to build scratch body
tubes as well. An excellent article on composite construction techniques
appeared in the XXXXXXXXXX issue of High Power Rocketry magazine. Another
article dealing with strengthening HPR rockets appeared in the XXXXXXXXX
issue.

The two most practical methods for strengthening the paper body tubes
used by LOC, THOY, etc. are 1) reinforce the tube with couplers for most
of its length and 2) wrap the tube with some type of reinforcing layer.

The first option produces a strong tube, but has the drawbacks of high
cost (at $2-4 per coupler) and high weight.

The most common material used with the second option is fiberglass cloth.
Two ounce cloth is good for use on 2.5 to 4 inch diameter tubes. Five
ounce cloth might be used for larger tubes. R.m.r posters have recommended
several techniques for applying the fiberglass. Here are two of them:

From: bmcd...@ix.netcom.com (Buzz McDermott)
1. Sand the tube with 320 grit sandpaper to slightly roughen its surface.
2. Mark a straight line down the length of the tube.
3. Lay out the fiberglass cloth on a flat, smooth surface. Use a square/
straight edge and a SINGLE EDGED RAZOR BLADE to cut the fabric to
a rectangle, allowing for at least 1" overlap around the diameter
and off each end of the tube to be covered.
4. Lay out and tape together enough wax paper on the floor of your
garage, basement, etc., to be larger than the fiberglass cloth in all
dimensions. Lay the cloth on the wax paper. Tape the wax paper to the
floor (but NOT to the glass cloth).
5. LIGHTLY spray one side of the cloth with 3M 77 adhesive. I mean
to put on a QUICK, VERY LIGHT coating of adhesive.
6. Lay the tube down on one edge of the fiberglass, using the line on the
tube as a guide to get the tube straight along the glass cloth.
7. SLOWLY roll the tube along the cloth, working out wrinkles with your
fingers. The 3M 77 should lightly tack the cloth to the body tube.
8. Once the cloth is on the tube, use thin *odorless* CA to seal the
overlap and edges along fin slots and ends of the tube. Using a
plastic
bag over one hand gently rub the CA into the cloth. Also CA any
wrinkles that are left. When the CA dries you can use the single edge
razor to trim off excess cloth at the ends, feather sand the overlap
joint (with 320 grit), cut out fin slot openings, and sand down or
slice off any wrinkles in the cloth.
9. Brush on 20 minute 'finish cure' epoxy. Bob Smith 'Coating Poxy' and
Hobby Poxy 'Smooth N Easy' are good choices. Completely cover the
entire cloth surface. Be sure and gently work the epoxy into the
cloth. You want the cloth soaked and the epoxy soaking into the
body tube.
10. About an hour after you finish, the epoxy should be getting real
'tacky'. Soak some rubbing alcohol into a clean, lint free cloth and
use that to lightly 'buff' the epoxy. This will help smooth the
coating and get rid of air bubbles.
11. After 24 hours, sand with 240 grit wet-or-dry, WET, until smooth.
You are now ready to prime.

Two additional notes:

1. With lighter cloth (3/4 up to 2 oz), I sometimes soak cyano into the
entire cloth surface. I then sand with 320 grit VERY LIGHTLY. I find
I use much less epoxy and end up with a lighter rocket. This is a
good technique when weight is critical.
2. Always wear latex gloves when working with epoxy. People do develop
nasty reactions to this stuff over time.

From wo...@netheaven.com (Wolfram v.Kiparski)

When using 3/4 oz. cloth, I find it easiest to first paint epoxy
(thinned
with a little laquer thinnner) on the body tube and then lay the cloth
onto the tube. The cloth readily "wets out" when it touches the epoxy,
and adheres to the tube without curling up. The cloth can be gently
arranged and gently brushed to smooth out the wrinkles as you wrap it
around the tube. Extra epoxy can be dabbed on as needed.

For 3/4 oz. cloth:

1. Cut the cloth to size first. Cut the cloth slightly oversize so that
it is a little longer than the tube, and will overlap if wrapped
around the tube.

2. Mix your favorite epoxy and add about 5% laquer thinner. Paint
this onto your body tube with a china bristle brush. I use a 1.5
inch brush. Thinning the epoxy makes it spread easier, and will
help keep lightweight cloth from distorting and wrinkling. It will
also cause you to use less epoxy.

3. While the epoxy is still "wet," drape one end of the cloth onto the
body tube. Use your brush to smooth the cloth out. Brushing in only
one direction will help avoid wrinkles. Roll the tube slightly as
you smooth the cloth onto the epoxy-covered tube. The cloth will
pick up enough epoxy to wet-out. If it doesn't, add a dab of epoxy
to help it along. You can free both hands by placing the body tube
over a long wooden rod like the kind used for closet hanger rods.
Support the rod at both ends kind of like a giant toilet paper
dispenser.

4. 3/4 oz. cloth will stick to the body tube and tend not to lift up
before the epoxy has cured. Be careful not to brush too vigorously
when overlaping the cloth as you finish applying it. You might
wrinkle the bottom layer of the overlap, and experience a great deal
of frustration.

5. After the epoxy has cured, lightly wet sand with 220 grit sandpaper.
Fill in any low spots with spot putty and sand smooth.
A few coats of primer will fill in the weave of 3/4 oz. cloth,
especially if you lightly wet sand with 320 grit between coats.

With a little practice, this technique is easy to do, and adhesives
other than epoxy are not required.

From da...@ddave.com ('Dangerous' Dave)
[Dave had the following comments about the above described technique.
Dave
is an expert in the use of composites, fiberglass and laminating
techniques]
When the glass is fully cured, you can sand the lap joint till it
feathers into the adjoining surface. Any irregularities can then be
filled with a polyester filler (Bondo) and spot putty to blend the
surface so that it is unnoticeable.

Don't use an adhesive to tack the glass in place. It will prevent the
resin from soaking into the fabric and will effect the physicals of
your epoxy. Cut your fabric to size allow and inch or so overlap that
you can trim off later. Wet your surface and then drape the fabric on
to it. Then stipple the resin into the fabric with a china bristle
brush. Don't use a paintbrush that is made from synthetics, i.e.:
nylon, polyester, ect.. The epoxy and/or your cleaning solvent will
dissolve your brush and it may react with the resin.

Be sure and read my Safety Document on handling composite materials
before you do any of this.

You will get your best adhesion by completely removing the glassine.
Since resin can't penetrate it and will not bond well, you must remove
it in order to take advantage of any strength gains you get from
applying glass.

Visit my web and ftp sites for some more info on laying glass.
FibreGlast at: http://www.fibreglast.com has a very good section on
composite techniques.

[Editor's note: If you're going to work with fiberglass, epoxies, or
carbon fiber, check out DDave's web page, www.ddave.com].

------------------------------------------------------------
11.8 Is there any way to retrofit my existing rockets to have some type of
positive retention system?

From bi...@PEAK.ORG (Bill Nelson):
Well, you can reinforce the aft ring a bit, then use the screw-in
threaded
connectors that are available.

From sil...@ix.netcom.com (The Silent Observer):
Drill a hole on each side, and install a Molly (R) or similar "drive
fastener" or expansion fastener -- the kind used for hollow walls and
doors. Do this with a dowel or motor casing in the motor tube, so the
little metal "legs" on the fastener don't punch through the tube; you'll
find these are about as strong as a blind nut, install from the front,
don't cost much more (if at all), accept standard threads (and come with
a screw!), and look neater. One thing to watch, though; the threads in
the fastener strip pretty readily (they're aluminum) and they're the
devil to remove if you do strip one.

From jsi...@ux1.cso.uiuc.edu (Jonathan Sivier):
I retrofitted blind nuts on a couple of my rockets using the anchor bolts
that are available at most hardware stores. These are a metal tube with
threads on the inside and slits along part of their length. You drill a
hole in your bulkhead, push the bolt unit through and tighten the bolt.
As it tightens the tube expands at the slits to push against the back of
the bulkhead. It also has a lip on the front so the anchor is firmly,
uh,
anchored. :-) With a little epoxy under the lip it becomes a very strong
mount for motor retention devices. They have different sizes for
different thicknesses of material, from 1/8" up. They may take up a bit
more room than the blind nuts, but if the rocket is already built
they are
a great way to make this improvement.

From kapl...@hccompare.com (Bob Kaplow):
Use threaded brass inserts, and a drop of thin CA to keep them in. They
don't have the large lip on the back, so it won't be as strong, but my
first 3-4 HPR models were done this way. Now I put blind nuts (also
called
T nuts) in all my larger rockets. I even use them in motor mounts
where I
have the room. DuBro makes some VERY SMALL 6-32 T-nuts that fit most
adapters that have a plywood ring. I've yet to come up with a retainer
for the heavy cardboard tube style adapters.

From: c72...@aol.com (Gary ??, C72500)
If you have already assembled the rocket, look for a "thinsert" and
installer tool. This is basically a threaded rivet -- drill a hole in
the
centering ring, put nose of tool (with insert threaded on) and squeeze -
permanently installed threaded insert! I have used this to retrofit
every
rocket I have built, and have yet to lose an insert or a motor.
Installer
and inserts are available through a company called Northern via
catalog -
runs about $13.
------------------------------------------------------------
11.9 All these high power motors are different sizes. How do I hold
them in? What do I use for a motor block and where should I put it?

From: jac...@sn3.jsc.nasa.gov (Al Jackson)
For mounting and retaining HPR motors I have this suggestion, especially
with PML models. See if you can let a good one inch of motor mount
protrude from bottom of model. Then when using a reload motor, besides
using a tape friction fit, put a wrapping of strapping tape around the
end enclosure and wrapped also around the piece of motor mount sticking
out.

From: jjir...@aol.com (Jerry Irvine)
Perhaps I'm just tired of seeing people reinvent the wheel to
non-round shapes, but I have found that:
1. There is no need for thrust rings inside rockets of any power or
weight. The application of a masking tape thrust ring on the
nozzle
end of the motor of adequate width for motor thrust is always
adequate, to the point where a fiberglass or metal one is better.
a. 1/4" wide masking tape is often used for 1/4A-F motors with
thrust levels under 40 newtons.
b. 1/2" wide masking tape is often used for 1/4A-J motors with
thrust under 200 newtons.
c. 3/4" wide masking tape is often used for F-K motors with thrust
under 600 newtons.
d. 1" up to 1000 newtons, 1.5" up to 2000 newtons, then above
that
a structural ring at the rear of the motor.
2. With the above system one can add an external motor hook with NO
protruding rear thrust block, extended out the rear the exact width
of the masking tape you most prefer. The hook should typically be
metallic and bonded to the outside with epoxy for maximum strength
and instead of protruding hooks, they can fan out to the side for
better bonding strength.

From kapl...@hccompare.com (Bob Kaplow):
You want to install blind nuts on the BACK side of the aft centering
ring,
before the mount is installed in the rocket. That way it can't pull
through.
[Epoxy a little around them]to hold them in place when not bolted in.
The
screws go into these threaded holes, and hold in whatever clip you are
using. I personally prefer cap screws and an allen wrench to machine
screws
and a flat blade screwdriver. The allen wrench holds the screw while I'm
installing it at a funny angle.

From bmcd...@ix.netcom.com (Buzz McDermott):
You can use blind nuts (also called T-nuts), available from many hobby
shops and most hardware stores. Two or three size 4-40 work fine for
up to 38mm motor mounts. For anything bigger I would use two or three
size 6-32 nuts. For three and four motor clusters that don't have a
central motor you can epoxy a balsa or spruce strip into the central
gap between the motors. Drill a 1 inch deep hole in the exposed end of
the strip appropriate for epoxying in a 2.5 inch length of 1/8" threaded
rod. Use a washer and nut to retain all three or four motors from a
central point.

Wolfram v.Kiparski

unread,
Sep 26, 2000, 3:00:00 AM9/26/00
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Archive-name: model-rockets/ignition-tips
Rec-models-rockets-archive-name: rockets-faq/part12
Posting-Frequency: monthly
Last-modified: 1996 January 9
URL: http://dtm-corp.com/~sven/rockets/rmrfaq.toc.html


Rec.Models.Rockets Frequently Asked Questions: PART 12 of 14

IGNITION AND LAUNCH SYSTEM TIPS

[Note: This portion of the FAQ is maintained by Jerry Irvine
(jjir...@cyberg8t.com).
All comments and suggestions should be sent to him.]

------------------------------------------------------------------
12.1 Copperhead, squib, electric match, thermalite, flash bulb.
What are all these types of igniters, how much current do they require,
and when are they used?

Copperhead used to ignite single composite motors; not
good for clustering. They will light most
black powder motors. Requires strong 12V
current source.

Electric Match a type of electric igniter requiring
little current to ignite. As little as 200ma
of current will set them off. Used for
igniting high power motors and motor clusters.

Thermalite a type of "igniter cord" used in pyrotechnic
applications. May be ignited by removing all of
the external bridge wired except one and using
wire wrap wire leads 1/4" apart 12v, or with an
igniter. Used in longer lengths and sheathed near
propellant cores it is used for clustering. Also
used in flashbulb ignition systems.

Firestar Igniter kit which has proven popular in general
use and is easily shippable. Uses low or high
current (6-12v) depending on which bridge wire
you dip in the parially pre-mixed solution you buy.

Flashbulb/thermalite some types of camera flashbulbs ignite
with very little current (typically as
little as 50ma) and burn very hot. These
are used to ignite a piece of thermalite fuse
running into the motor. Used for igniting
high power motors and all forms of clusters.

Magnelite medium to high current requirements. Sold
by Rocketflite to ignite Silver Streak
motors. Work well to ignite single high
power motors. These are magnesium tipped
igniters that burn at a very high temperature.

In general, almost any current source from a 1.5V 'C' battery up might
ignite a flash bulb or electric match. For the other igniters, a 12V
system capable of delivering several amps of current to the igniter is
required.
------------------------------------------------------------------
12.2 How do those 'Copperhead' igniters work? They only have one wire?

Copperhead igniters are actually two strips of copper wire with a
thin mylar insulating layer between them. To use these with regular
alligator clips you need to use masking tape to insulate opposite sides
of the igniter from each clip.

'Thin' (side) view of copperhead igniter:
| |
|______| < Motor with Copperhead inserted
||
Masking > ||
tape > ||
||
||< Masking
||< tape
||

Attach one alligator clip at each masking tape point, so that each clip
only makes contact with one (opposite) side of the igniter.

The Quest 'Tiger Tail' igniters are the same type of igniters as
Copperheads. They come with a special 'wrapper' with openings for
alligator clips.

NOTE: Copperhead igniters require a 12 volt ignition system.
------------------------------------------------------------------
12.3 I've heard that Copperhead igniters are 'unreliable' for igniting HPR
motors. Is that true?

Many HPR flyers do not like the Copperhead igniter, preferring alternatives
when they can be found. It is certain that Copperhead igniters are not
a good choice for igniting clusters. However, some have found the
Copperhead to be a reliable igniter for single-motor HPR rockets.

From: dcr...@mizzou1.missouri.edu (Elmer M. Price)
Hi Folks: I have a comment on the reliability of Copperhead igniters.
Our small group has had no problems with these, once we figured out the
best way to use them. So, in spite of all the negative comments, we
actually really like these things. We have launched composites up to
and
including I-sized motors with great reliability. For example, two weeks
ago, two of us (at the excellent St. Louis launch), launched two I284
birds, one I161, one I211, two H123 and a few F's and G's. We had 100%
igniter success.

O.K. So what do we do to achieve such reliability? First, open the
reload pack and assemble the motor in the usual manner. Second, find
the
Copperhead that came with the reload kit and THROW IT AWAY. What we use
are Copperheads which we purchase separately. These arrive from the
dealer (like Magnum) in a nice package and the igniters are not all beat
up and crimped and bent to heck like the ones which are provided in the
reload kit. We feel this is an important point. Second, since the H and
I (and larger) motors are a bit more difficult to light, we modify the
new Copperhead as follows (this idea came from RMR): take a slug of
white lightning propellant (we use the slug from a D9) and cut a very
small sliver (and I mean small, about 1/16 inch square and about 1/2
inch
long). Tape this sliver (Fred from our group optimized this point) to
the Copperhead by overlapping the bottom half of the pyrogen on the
Copperhead with the top half of the sliver. Use a small strip of
masking
tape to attach the sliver to the copper below the pyrogen. The point
here is to ensure the tape is below the area where the pyrogen and the
sliver overlap. This is important because if the tape is higher up the
igniter, the sliver may fall off of the Copperhead and lead to a chuff
(ignition too far aft).

This modification is not necessary for G and smaller motors, since the
pyrogen is in close proximity (or touching) the propellant.

And this was added by: bd...@fly.HiWAAY.net (Brian Day)
I've also gotten *MUCH* better reliability from Copperheads by not using
the red plastic cap over the nozzle, and just using a small piece of
masking tape to hold the igniter in place. This technique doesn't crimp
the Copperhead like the plastic cap does. Since doing this, I've gone
from roughly 50% reliability to darned near 100%.

Oh yeah, someone else on rmr recently suggested clipping off the pyrogen
part of an old, crummy Copperhead and using it to augment another
one, like
you do with your sliver of propellant. Beats throwing it away...

Finally, regarding the red caps provided with Aerotech motors for holding
in the igniters,

From: Bob Kunz <bk...@boi.hp.com>
You do know that one is supposed to provide a vent in the red cap? I
would
presume this is to allow some leakage of pressure but enough to get the
white/blue/black propellant to ignite. Typically, I find that the red
cap
is blown through when I recover the rocket. Only once was it blown
off at
the launch pad. So far in about a dozen launches on RMS 24/80, I've
had no
failures. But sure those are small grains compared to some of the 54mm
stuff.

From: cur...@telerama.lm.com (Larry Curcio)
Copper Head igniters have acquired reputations for unreliability. I'm
wondering if the problem is in the igniters or in the red nozzle
caps, which blow off during most Copper Head failures. IMHO, it's the
sudden release in pressure that makes ignition fail - by disrupting the
newly forming flame. When I use a piece of masking tape instead of a cap,
I don't seem to have the problem.

Editor's note (jjir...@cyberg8t.com):
As of 11-96 Aerotech has made some efforts to eliminate the microshort
problem which is an artifact of the Coppercrap manufacturing process.
They have tried making versions with thicker insulator layers.
While they are more fragile and subject to peeling, they are more
reliable than before. Time will tell.

------------------------------------------------------------------
12.4 Do you have any specific suggestions or tips for an ignition power
sources? Can I use my old Estes ignition system with composite models?

The Estes, Quest and other model rocket launch systems are fine for most
model rockets. If you do a lot of flying there have been some suggestions
posted to the net. If you are trying to launch cluster models with solar
igniters you will need more 'juice' than 4 AA batteries can provide. This
is also true of clustered Copperhead type igniters.

From: c...@sw.stratus.com (C. D. Tavares)
A motorcycle gel cell, however, will last a long, long time.
Our club uses a gel-cell the size of three VHS tapes to launch 120
rockets over six hours, and it comes home at about 80% charge.

From: bi...@hpcvaac.cv.hp.com (Bill Nelson)
I bought a 12 volt motorcycle battery for about $20. I only need to
recharge it 3 or 4 times a year. I have adapted all my launch
controllers to allow usage of the battery.
------------------------------------------------------------------
12.5 WARNING: Be very careful using any ignition system with 'flashbulb' or
electric match type igniters.

Many (most?) launch ignition systems are not 'flashbulb safe'. Just
arming the circuit (i.e., doing a continuity check) will fire the
flashbulbs and ignite the motor. If you plan to use flashbulb ignition
often, you might consider investing in a 'flashbulb safe' ignition system.

From J.C...@ens.prime.com (Jim Cook):
A lot of launch systems use a light bulb to do a continuity check.
The current through the light bulb is enough to set off flash bulbs
(They require only milliamps to fire).

Remember that electric matches may ignite on any amount of current above
200 milliamps. Flashbulbs may ignite with as little as 50 milliamps of
current.
------------------------------------------------------------------
12.6 The ignition of rockets by other than electrical means is banned by both
the NAR and Tripoli safety codes and should not be used.

There was a fairly lengthy discussion in r.m.r about the use of hand-lit
fuse to launch rockets. Although there was an advocate of this method the
consensus opinion of the net was that the NAR and Tripoli safety codes
made good sense, hand-lit fuse igniters were unsafe, and electrical
ignition (even if igniting fuse by electrical means) should be used for
all activities. Hand-lit fuses are also against most state laws.

While it is theoretically safe and practical, it goes against the
principal of self regulation which has made model rocketry legal and
available natonwide and worldwide. Just don't do it.
------------------------------------------------------------------
12.7 What is thermalite fuse and how is it involved in igniting rocket motors?

Thermalite is is a brand name for igniter cord from CXA Ltd of Canada.
It comes in three burn rates, identiflyable by the color of the fuse
wrapping:

Color Type Burn Rate Usage
Pink Slow 20 sec/foot Flashbulb ignition
Green Medium 10/sec/foot Ignition enhancement
White Fast 5 sec/foot Not used much in rocketry

The burn rates are approximate and vary with humidity, temperature, age
of fuse, etc. The numbers also correspond to burn rates of exposed
thermalite. When enclosed in heat-shrink or Teflon tubing, all three
types burn at an equally fast rate. A typical usage for thermalite is
in a flash bulb igniter:

| < 1/2 to 3/4 inch of thermalite exposed out
| < end of sheathing
|||
||| < thermalite fuse in Teflon or heat-shrink
||| < tubing (fuse should *just* fit into tubing)
|||
|||
+ |
+ +| < 1/2 to 3/4 inch thermalite exposed out end
flash bulb > + +| < of sheathing and taped to flash bulb using
+ + < CELLOPHANE tape (NOT masking tape).
+
/ \
/ \ < electrical leads to ignition system

The fuse is sheathed except for about 3/4" at each end. The sheathed fuse
is inserted into the motor and must be long enough for the exposed end to
go all the way up through the core and out the bottom of the motor.
Composite motors are ignited at the top of the core (nearest the delay
charge). The sheathing on the fuse is to keep from igniting the motor
anywhere but the correct location. The other end of the fuse is tape to
a hot-burning flash bulb. The flash is then attached to the ignition
system and ignited in the normal fashion. This lights the thermalite
fuse, which then ignites the motor.

This is the ignition method of choice for clustered composite motors (in
any number above 1) and large clusters of black powder motors.

WARNING: Flash bulbs require VERY LITTLE current to set them off. Read
the warnings above.

NOTE: Thermalite is classified by the BATF as a 'Class B Low Explosive'.
Out of state purchase, interstate transport, and personal storage
of *any* amount of thermalite fuse requires a Federal Low Explosives
User Permit. Refer to the section on 'High Power Rocketry' for
more details on LEUPs.

This is a change of prior enforcement practice and this material
was widely available as a Class C item for decades. We will see how
long this will last. Several advocates of easy access have
suggested
that short lengths of under 12" should be exempt from LEUP and
shipping restrictions, especially those pieces included as stock
igniters with MR and HPR motors from the factory.

Thermalite is one of those magic and critical substances to
rocketry.

------------------------------------------------------------------
12.8 How do you ignite second stage composite motors?
Can I use a black powder booster for the first stage to ignite the
second (as I do with multi-state A-D rockets)?

Upper stages of composite powered models may be ignited by
electrical means or thermalite fuse. North Coast Rocketry (NCTRA2) and
California Rocketry (AIR-3) have technical reports covering this subject.
Excellent articles have also appeared in Sport Rocketry/AmSpam and
HPRM magazines.

You cannot use a black powder booster to ignite a composite upper
stage. The gasses from a BP booster will not properly ignite a
composite. There are composite boosters on the market. These boosters
are all 'plugged' and so cannot ignite any type of upper stage motor.
Composite motors are mostly 'core burners' with the core running the
entire length of the fuel grain. A composite core burner set up like a
BP booster would ignite a BP upper stage too soon.

There are several issues involved in igniting upper stage composite
motors. (1) A timing method must be provided to delay ignition until
the appropriate time, (2) power source for the igniter is required and (3)
the igniter itself must be provided and be capable of igniting high power
motors. Whatever method of ignition is chosen, all 3 criteria must be
met.

Timing Methods ....

Several methods of timing have been developed and used. The earliest and
cheapest timing method is to use a length of unsheathed thermalite fuse.
The fuse is typically ignited by the exhaust from the first stage motor.
The fuse is long enough to allow for the first stage motor burn time and
any desired post-burnout coast. The last portion of the fuse is sheathed
and inserted into the upper stage motor to act as the igniter. The problem
with this method is that not all thermalite burns at the same rate. Also,
the same batch of thermalite will burn at different rates depending on the
altitude, temperature and humidity at the time and place of launch.

Mercury switches were another early method of 'timing' upper stage
ignition. A mercury switch is a small glass bulb with an enclosed drop
of mercury. Two wires run out the top of the bulb. When the switch
is tilted or decelerated the mercury rolls forward to make contact with
the two wires and close the circuit. This results in a closed circuit when
the booster motor stops firing and the rocket begins to decelerate. The
ignition circuit would be set up so that power is provided to the igniter
when the mercury switch closes. EXTREME care must be exercised when
using
mercury switches. Titling the rocket closes the switch, so provisions for
disarming the circuit must be included. After the rocket is placed on the
pad and the circuit armed, any sudden movement of the rocket could set of
the second stage.

Bob Weisbe uploaded plans for a mercury switch-based staging system that he
used in a converted Estes Terrier-Sandhawk kit. The URL for these plans
is:

http://sunsite.unc.edu/pub/archives/rec.models.rockets/PLANS/terrier_sandhawk.ps

The next generation of upper stage ignition systems were based on
electronic timers of various types, both analog and digital. The timer
was set for the appropriate time (first stage burn time + inter-stage
delay, if any). A contact switch, usually kept open by the launch rod,
would often be used to initiate the timer. As the rocket leaves the
launch rod the timer is started. After the preset time interval the timer
closes the circuit allowing power to the igniter. Again, great care must
be taken with these devices. If the contact switch is allowed to close
prior to the rocket lifting off the 2nd stage could ignite while the
rocket is still on the pad and there are people around.

Another form of early timing device was based on photo-electric sensors.
A sensor would be placed in a position such that light could get through
the booster motor tube after all of the fuel was spent. When the sensor
detects light the power circuit is closed.

Remote control has been used to initiate firing sequence in multi-stage
rockets. This method has the advantage that the 2nd stage isn't ignited
unless a human being takes positive action, while the rocket is in the air.
It also requires an R/C transmitter, receiver, etc.

Some newer devices are out based on acceleration detection. These are
sometimes combined with timers. Liftoff acceleration is detected. This
either starts a timer or enables a deceleration sensor. At the specified
time interval, or when deceleration is detected, the power circuit is
closed.

Power Sources ...

Two forms of electric power are commonly used, capacitors and batteries.
A capacitor is typically charged from an external source just before
liftoff. The timing device then closes the circuit at the proper time
and the capacitor discharges, firing the igniter. One disadvantage of
this method is that the capacitor charge slowly bleeds off, meaning that
the rocket may not sit on the pad a long time after prepping and still
reliably ignite the upper stage(s).

All forms of small batteries have been used, depending on the power
requirements. Common batteries for igniting a single, low power igniter
are 9V transistor and 12V alkaline lighter batteries.

Timed thermalite fuse ignited by exhaust from the booster requires no
power.

Igniters ...

Multi-stage rockets generally have a limited current source for igniting
upper stages, so very low power igniters are used. Two common igniters
are electric matches and flash bulb/thermalite fuse. Both of these
igniters are described elsewhere in this document.

Readers are encouraged to review the NCR technical reports and rocketry
magazine articles on composite multi-staging.

A document describing igniters, and how one can make ignitors using
thermalite and nichrome wire is available on the sunsite archive at:

http://sunsite.unc.edu/pub/archives/rec.models.rockets/ARTICLES/igniter_talk.txt

Illustrations for this document are also available for downloading:

http://sunsite.unc.edu/pub/archives/rec.models.rockets/ARTICLES/igniter_talk_fig
ures.ps

------------------------------------------------------------------
12.9 What is 'flash in the pan' ignition and for what is it useful in
rocketry?

From: jjir...@cyberg8t.com (Jerry Irvine)
[Editor's note: This is paraphrased from Jerry's postings]
Flash in the pan ignition is used to ignite clusters of small black powder
rocket motors. It consists of a thin layer of black powder on a paper
plate

under the motor nozzles. The powder is ignited via a regular model rocket
igniter, such as an Estes Solar igniter. When the power ignites, the
burning particles and hot gasses from the 'flash' ignite the motors.

It is used to ignite clusters of 7-469 motors and reduces the number of
igniters needed to one.

------------------------------------------------------------------
12.10 I would like to perfect a method for reliable ignition of clustered
multi-
stage rockets. Any suggestions or tips?

From: Levi...@nighthawk.medtechnet.com (Leviathan)
So would everyone else... but there's always that chance that something
may fail when staging and/or clustering... and probably double the
chance
when staging & clustering. Therefore, my best advice to anyone
attempting
(large?) projects requiring staging/clustering is to invest in some sort
of recovery system such as the Adept altimeters with deployment. In the
case of staging... if the upper motor fails to ignite the altimeter will
still deploy the upper stage chute(s) SAFELY with NO damage to the
rocket.
In a case were you're clustering and a motor (or 2, or 3....) fails to
ignite in the cluster, and the rocket WILL fail to reach a safe
altitude -
or more precisely now WILL have a delay time that is TOO LONG -
again the
altimeter will SAFELY deploy the chute(s). IMO it's a small price to
pay to
protect a much larger investment of the rocket itself. As a matter of
fact
in my current project - a 1/4 scale 3 stage Argo D4/Javelin - each stage
will carry it's own altimeter with the 3rd stage carrying the Adept OBC2
recording altimeter. Not only will this provide for dual deployment of
each stage's recovery system, it should provide protection against
failure
of the 2nd and/or 3rd stage ignition. I also plan on carrying a Pratt
system aboard to provide redundant back up.

From: John Dunbar <jdu...@csd.sgi.com>
I really recommend the Teflon sheathing method of thermalite.

Now you can try using a flash pan to get that first stage bohemian
going.
Its just a nice circular pan, with fine black powder in it. Just order a
can from your local gun shop, they can ship US postal to your front door
without a single eyelash batting on the face of a BATF agent. You stick
those engine down into the power with a thermalite wick protruding from
the engine, and WHOOSH...

The more parts you have to worry about, the greater the likelihood that
something is going go terribly wrong. Now if you don't care, and just
want to do it for fun, GO FOR IT, otherwise think of ONE BIG MOTOR
for the
first stage and one smaller, yet BIG MOTOR, for the second. Do not rely
on mercury switches for high power ... that's a NO NO. Instead, use
timers
in a way that causes the second stage to start its ignition while the
first is still under power. Now you can drag separate, and that's
fine to,
but make sure your bird is flying straight and true, or it will be
doodoo!

Technical reports on this subject are available from NARTS and California
Rocketry (see part02 of this FAQ):

California Rocketry report AIR-3

North Coast report NCTRA1 (from NARTS)

------------------------------------------------------------------
12.11 How do I cluster rocket motors? When igniting a cluster of rocket
motors, should the igniters be wired in parallel or in series? Why?

The advent of composite model rocket motors in 'standard' black power
sizes (18 and 24mm) has led to an increase in the use of composite motors
in cluster rockets. Mixed black powder/composite clusters are also
becoming popular. In particular, clusters of 3 or 4 composite
motors, or a composite core motor with outboard black powder motors,
are being seen more. These offer special ignition challenges. The old
black powder techniques don't work when composite motors are
involved. The most common method for clustering Estes type black
powder motors is to use multiple Solar igniters and clip whips. Flash
bulb to sheathed thermalite is the most common composite ignition
method. Although flash bulb ignition has been used for years, there
have been safety concerns over its use. Here are some suggestions from
rmr posters:

From Pete...@aol.com (Peter Alway):
I cluster black powder motors with Solar igniters wired
in parallel and a car battery for power. I stuff igniters
with little balls of tissue paper wadding to insure they
stay in place. My general rule is only to cluster with
a technique I use regularly for single-engine models,
as reliability has more to do with experience and my
current state of skill than with the particular technique.
[Editor's note: Estes plastic plugs work well in place of tissue
wads. The igniter plugs can be reused several times, as well.]

From: gl...@lightning.nsc.com (Glenn Newell)
My technique for clustering composite motors is to use equal length
pieces of thermalite with 1/16" heat shrink tubing as a sleeve. I
leave about a 1/2" unsheathed in the motor and about one inch unsheathed
on the other end (I don't shrink the heat shrink, it just happened to be
around and the right size). I tape all the ends together around a single
solar igniter. No flashbulb problems here!

From: bi...@hpcvaac.cv.hp.com (Bill Nelson)
I prefer to use a short section of Thermalite, with igniter wires,
inserted into each motor - the wires are taped to the motor for security.
There is no need for an igniter for the Thermalite. Simply remove the
cloth wrap, and all but one of the spiral metal wires. Wrap the end of
one wire to one end of the thermalite and the end of the other wire to
the other end. You can use anything from about 22 gauge wire (if it will
fit in the grain slot) to about 28 gauge. The free ends connect to the
controller ignition wires. When the relay closes, the Thermalite wire
wrap is essentially vaporized instantly. I have never seen the
Thermalite fail to ignite.

From: bur...@kodiak.ee.washington.edu (Frank J. Burke)
The main reason for using parallel igniters is that as one ignites, the
others are still in the circuit. As one igniter breaks in a series
circuit
the circuit is broken and the others will not get any more current.
It may
be that with a 12V system, and low impedance wire, that the current
provided is high enough that they flash so fast that it doesn't
matter....
I have never had a failure with parallel circuits. I ... prefer using a
parallel system, knowing the limitations, using a meter to verify
that the
igniters are "good" before using them, and using good connections when
wiring them up.

From: buz...@netcom.com (Buzz McDermott)
The biggest concern with wiring cluster igniters in series is that one
igniter might burn through and break the circuit before all of the
igniters have fired. Once the circuit is broken, no more igniters will
fire.

On the other hand, it was mentioned by several posters that series wiring
is extensively used in the explosives and pyrotechnics industries
because of the added reliability you get. With series wiring you can
verify the complete igniter circuit and you will know if *any* igniter
is improperly wired. Also, you would be able to ignite many more (fast
igniting) igniters with series wiring, especially if the resistance
in the
igniter is high.

From: kapl...@eisner.decus.org (Bob Kaplow)
For a 4 engine cluster I like to wire the ignitors in a "bridge":

X======B
/ \
/ \
/ \
/ \
/ \
/ \
/ \
A ======X X======A'
\ /
\ /
\ /
\ /
\ /
\ /
\ /
X======B'

Clips A and A' come from one clip whip. B and B' are from the other
whip.
I use a manual wire wrap tool for twisting the Solar ignitors together
AFTER installing the "earplug" (tm). Be sure your wraps are nice
and tight
so they all touch where they are supposed to. Having a clip on each
joint
certainly helps. For multiple wire clipping, I've found that the
clips with
teeth hold better than the standard micro-clips.

I've used this several times now on 4xD12 in a BT-80 rocket with
100% success.


Editors Note:
The bottom-line-consensus of the 'net' seems to favor parallel wiring for
most clusters of 7 or fewer motors, using a 12V (or more) launch system
capable of dumping plenty of amps to the igniters. This generally means
a relay based system with the primary ignition power source close to the
launch pad.

Readers are also directed to check out the NCR Technical Reports #1 &
#2, on black powder and composite clustering, respectively. Although
they are a few years old, they still contain valuable information.

------------------------------------------------------------------
12.12 I am new to rocketry. I was wondering whether anyone has tried
using waterproof wicks instead of igniters to ignite a rocket engine.

The main application for Green fuse in rocketry is as an auxuliary delay
when a timer is not available and Thermalite is too fast burning. Green
Visco fuse burns about 30 seconds per foot.

From: Robert...@hccompare.com
"Green" fuse isn't reliable, and unless electrically ignited via remote
control (difficult) isn't legal. To use fuse and a match is a
violation of
the safety code, and most state local regulations.

buz...@netcom.com (Buzz McDermott) adds to the above:
The most common way to use 'green' fuse or Jetex wick to ignite a model
rocket motor is to cut a fair length, insert it in the motor, light it
with a match, and RUN!. As Bob stated, it's against EVERYONE's safety
code to do that. The answer to 'why' is simple. Once you light the fuse
you've lost all control over launching the rocket. If a breeze kicks it
over just before ignition you end up launching a land shark. You can't
stop the launch if you notice a plane come out of nowhere and fly right
overhead. You can't stop the launch if a little kid comes out of nowhere
and runs up to your rocket. ...on top of all this, the stuff just
doesn't really work all that well for rocket ignition...
------------------------------------------------------------------
12.13 The alligator clips on my launch system have worn out. What should
I use to
What should I use to replace them?

From: msjo...@KS.Symbios.COM (Mark Johnson)
RatShack is fine for clips...and they have a wide collection of
sizes. My
suggestion, having been-there-done-that and replaced clips on several
controllers almost annually, is NOT to buy the little 3/4 inch copper
clips.
They're too delicate for my tastes. Instead, I get the chrome plated
ones
about 1 1/4 inches long, preferably with the little plastic grips on the
"handles." These are bigger and thus easier to manipulate while wearing
gloves, or when your hands are cold and unsteady.

If you use your launch system frequently, I recommend at least annual
replacement of the clips. This is more true of a club system than an
individual one, but remember that you take your choice of corrosives
with
model rocket motors -- black powder leaves just a bit of sulfuric
acid in
its wake, and composites drop hydrochloric. The clip bodies of copper
micro-clips will hold up OK, but the spring that holds the jaws shut is
steel and will eventually corrode away, as you've seen.
------------------------------------------------------------------
12.14 Other Ignition Tips:

From: dw...@jarthur.claremont.edu (Doug Wade)
[concerning adapting launch controllers to 12V car batteries ...]
Speaking of which, I took my Aerotech launch setup, lopped off the
igniter attachment, and the place where it attaches to the battery, put
amp plugs on either end, put a plug on the battery, and made some
alligator clips in various configurations for launching Estes stuff.
This means that I can switch batteries and igniter style in basically
no time at all. It's not a lot of work, and it makes life easier. If
you have the urge to do this kind of thing, make sure that you get
plugs that can handle it. A 12V motorcycle battery (Mine was about
$40 but it's pretty nice) can put out something like 15A for a short
period of time...

From: c...@rocket.sw.stratus.com C.D. Tavares
[concerning an ongoing discussion about blast deflectors]
I've had first hand experiences with several types of metals. I've never
found a piece of aluminum that was worth dog-doo as a deflector. In the
higher engine ranges, even steel will give you problems, especially with
maintenance. Stainless isn't much help, since it still cruds up.

What we use are discarded grinding wheels. Fireproof, non-conductive,
free, plentiful, large, and pre-drilled. The only negative on these is
that when an engine catos they tend to lose large chunks or crack in
half. This happens to us maybe three times per year, but as I say,
they're free and they're plentiful.

Wolfram v.Kiparski

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Archive-name: model-rockets/international
Rec-models-rockets-archive-name: rockets-faq/part13
Posting-Frequency: monthly
Last-modified: 1998 September 26
URL: http://dtm-corp.com/~sven/rockets/rmrfaq.toc.html


INTERNATIONAL ROCKETRY

The majority of the r.m.r FAQ is oriented towards consumer rocketry in
the United States. This part of the FAQ is for rocketry in other parts
of the world. These sections will be expanded as information is received.
---------------------------------------
13.1 Rocketry in Australia

This portion of the FAQ was prepared and submitted by Rob Masters,
r...@perv.metapro.com.au. Rob asked that the usual disclaimers to
use this information at your own risk, etc., be passed on to the readers
of this FAQ. Corrections should be sent to Rob, who will see that they
are incorporated and passed on the the FAQ editor.
---------------------------------------
13.1.1 What rules apply to model rocketry in Australia?

The C.A.A. RULE (Paraphrased from regulation 295):
No model may be flown over 300' without a waiver from the
CAA. Only matters relating to airsafety shall be considered in
granting a waiver. Further, you may not launch at all within
5km of an aerodrome (airfield or airport). Also, some states
have explicit age restrictions (ie Queensland - Minimum age 18yo),
and fire restrictions (Qld again, must have local fire marshall
approval). You should also respect fire bans as a matter of
safety, courtesy and good public relations.

Other than this, you should follow the standard _model_
rocketry rules of the NAR, and note that only engines up to
"D" class are available.
---------------------------------------
13.1.2. What are good sources of model rocketry kits/wg's/parts, etc?

To date, all model rocketry components are imported through
DAWN TRADING, who the distribute to the local retailers. Note
that because of their policies, it is not possible to buy
individual components for kits in Australia. The Designer's
Special component set is, however, available. Currently only
Estes and MRC kits are imported. Local retailers are most R/C
retailers and some gaming shops.
---------------------------------------
13.1.3 Are there any regular rocket contests, launches, clubs, etc?

There is at least one national-level body now in Australia. It
covers both model rocket and HPR levels. The body is :

Australian Rocketry Association Inc.
P.O. Box 125,
Oaklands Park SA 5046

Email: das...@cs.adelaide.edu.au (David Sakko, Vice President)

Membership is $25 per annum, and an additional $10 per annum per
additional family member. Minimum age is 8yo and membership includes
insurance, a quarterly newsletter, ID card, and guide book.
Sport Rocketry is available through them at $40 (surface) or $92 (air)
per annum.

The association is also working with the CAA, state governments and
the AFPA to standardise regulations and to obtain better flying
conditions.

Also, there is at least one model aircraft club that welcomes, but does not
cover, model rocket launches. For the scale modellers, there is also an
active Astronautical Society, who can provide a lot of information,
and are well worth joining if you are interested in the world of the
"big stuff" as well.
---------------------------------------
13.1.4 Info on amateur groups/activities (such as AusRoc) in the Australia.

As has been covered in news stories, there is a University-based team
who are working on an amateur rocket (AusRoc), who have so far had
two spectacular failures, and one partial success.
For more on the AusRoc project, contact The Australian Space Research
Institute. If you would like to join the Australian Space Research
Institute write to:

ASRI Ltd.
PO Box 184
Ryde NSW 2112
Australia

The annual fee is AUS$25 for students and pensioners and AUS$100 for
normal membership. If you live overseas write for membership costs.
All member funds are used to support ASRI programs. Membership allows
you to:
* Vote at meetings
* Stand for election to the ASRI board of directors
* Receive of all ASRI newsletters and journals
* Provide payloads for Sighter (83 mm) and Zuni (127 mm) rockets

---------------------------------------
13.2 Rocketry in Canada

3. Regs: HPR is class H-O. G's now available. HPR launch sites require
certification by Transport Canada. HPR certification done by CAR.

This section is still under construction and currently has no Canadian editor
responsible for its contents. Most of the information contained in this
section was obtained from the CAR World Wide Web page and several issues


of 'High Power Rocketry' magazine.

---------------------------------------
13.2.1 Are there any national organizations to which I can join in Canada?
What services do they offer?

Canadian Association of Rocketry (CAR) Canadian equivalent to N.A.R.
c/o Garth Illerbrun - High power certification
5927-18th Ave. N.E. (required for H power and up)
Calgary, Alberta - Dues: $30/year CDN
AB T1Y 1N9 - $1M liability insurance for
Canada rocketry activities included
(403) 285-1898
email: - Yearly national sport launch
qui...@cadvision.com (Sullivan Lake)
WWW: http://www.promotek.com/car/index.htm


Calgary Rocketry Association (CRA)
fan...@cadvision.com (Brian Fanson, current CRA president)
http://www.ucalgary.ca/~dbuhler/cra.htm
---------------------------------------
13.2.2 What kinds of rockets (model and/or high power) are legal to fly in
Canada?

At the present time, A-G powered model rockets, with launch weights up to
one pound, are legal to fly in most parts of Canada. H powered rockets and
up, as well as rockets weighing more than one pound at liftoff, are considered
'High Power.' HPR launch sites require certification by Transport Canada.
HPR certification is done by CAR.
---------------------------------------
13.2.3 Are there any High Power launches in Canada?

There are several annual high power launches in Canada.

The 'Sullivan Lake High Power' launch.

For more information on this launch contact Garth Illerbrun
<qui...@cadvision.com> at the CAR address.
---------------------------------------
13.2.4 What kinds of rocket motors are available for purchase in Canada?

All of the Estes A-D black powder rocket motor line and the Aerotech
single-use, composite motors from D through G are now available for
purchase.
---------------------------------------
13.2.5 Are there any Canadian mail order houses where I can purchase model
rocket kits, motors and supplies?

East Coast Model Center
http://www.peinet.pe.ca/ECMC

Ralph's Hobby Shop Advertises Estes, MRC and LOC, as well
668 Kingston Road as modeling and ignition supplies
Toronto, ONT
Canada M4E 1R4
(416) 690-4204
email: ralphs...@sympatico.ca

La Maison de L'Astronomie Offers rocketry supplies from Estes,
7974 St-Hubert Aerotech, Flight Systems, LOC, Rocketman,
Montreal, QUE Public Missiles, Adept, and more
Canada H2R 2P3 Kits, motors, videos, books - everything
(514) 279-0063 contact for catalogs and price lists

Suborbital Technologies Estes, Aerotech, NCR, Launch Pad
c/o Brian Fanson rocketry kits, motors, supplies
179 Midlawn Close S.E.
Calgary, Alberta
Canada T2X 1A7
(403) 256-7293
email: fan...@cadvision.com

---------------------------------------

13.3 Rocketry in the United Kingdom


http://www.gbnet.net/orgs/staar
http://www.gbnet.net/orgs/seds
---------------------------------------
13.3.1 Is model rocketry legal in the UK?

As far as we can tell, there are no laws in the UK which *directly* govern
model rocketry in the UK. For the time being, with model rocketry only in
its infancy (10yrs or so) there is little need for unnecessary regulation
so long as model rocketeers follow 'commonsense guidelines'.
---------------------------------------
13.3.2 What size model rockets can be flown?

Again, as far as we can tell, there are no rules which define maximum sizes,
weights, total impulses etc. Most model rockets that can be bought from model
shops will take a maximum of 3 D-Class Estes motors, either clustered or
multistaged. There appears not to be an equivalent of an FAA Waiver for
launching rockets greater than a defined maximum. However, all of the HPR
enthusiasts I know do contact the CAA (Civil Aviation Authority) if they
wish to launch over approximately 3000ft.
---------------------------------------
13.3.3 What model rockets are available?

The complete Estes range of kits and motors are available (not Estes E15).
The Estes range is imported/distributed by Ripmax Ltd (See addresses below).
Recently, a range of 'Launch Pad' kits has been made available by mail order
from a company called Advanced Rocket Components (See addresses below).
These will fly on Estes D and Aerotech E15/E30 engines. I do not know of any
other source of rocketry components in the UK.
---------------------------------------
13.3.4 What types of engines are available?

Estes engines are the only commercially available brand of model rocketry
motors available in the UK. All sizes from 1/2A to D are available.
The price can vary quite wildly from one store to another. Typical
prices in London are about GBP4.00 for 3 C/D Class. (Prices can vary from
3 to 5 GBP!)

Larger motors such as Aerotech etc.. are not available.
---------------------------------------
13.3.5 Where can I buy model rockets?

In general, it is the smaller independent model shops that sell model
rocketry supplies, however, larger chains such as Beatties and Hamleys
have been known to stock them. A number of 'kite and juggling' shops also
sell Estes products too - quite interesting! (See address list below).
---------------------------------------
13.3.6 Are there any events/competitions?

There is only one event that I have come across, which is the "International
Rocket Weekend", which is held near Largs, Scotland. This is run by
STAAR Research (See addresses below) and is held on the August Bank Holiday
every year (Note that Scotland does not have a Public Holiday, only England
and Wales!).

There are no formal rules and regulations like the NAR, Tripoli etc.
The basic rules and events are laid out beforehand, but often change to suit
the interests of those attending. The event is aimed at promoting model
rocketry in the UK, and often has a number of beginners. There are also
many 'open/experimental' sessions for the more experienced.

The most important thing is that everyone enjoys themselves.
---------------------------------------
13.3.7 Are there any clubs?

The following is the list of clubs/organisations that I have come across.
[I will try to establish full contact details ASAP]

- STAAR Research, Ayrshire.
http://www.gbnet.net/orgs/staar/

- Southern England Rocket Flyers (SERFS), Southampton.
http://ourworld.compuserve.com/homepages/steve_moores

- British Space Modelling Association
Mr. Stuart Lodge
25 Huntingdon Drive
Castle Donington
Derby DE74 2SR
UNITED KINGDOM
Tel: 44 1332 850329

- Thrust (The Rockect Club of Central England)
email: thr...@bidesign.demon.co.uk

- Middlesex Advanced Rocketry Society (MARS), Middlesex. (HPR Group)

- London Area Rocket Flyers Society - contact John Lister <jo...@listers.demon.co.uk>

- Beatties of London Model Rocketry Club.

- Essex, Hornchurch - contact Peter Barrett (10154...@compuserve.com)

---------------------------------------
13.3.8 What are addresses of some of the shops that carry model rocketry?

RIPMAX Ltd. Tel. 0181-804 8272
Ripmax Corner Fax. 0181-804 1217
Green St.
Enfield
EN3 7SJ

Chart Hobbies Tel. 01903 773170 (On Estes Catalogue back page)
Chart House Fax. 01903 782152
Station Road
East Preston
West Sussex
Littlehampton
BN16 3AG

Hamleys Tel.
Regent St. Fax.
London

The Kite Store
Neal St.
Covent Garden
London

Advanced Rocket Components Tel. 0151-928 4874
7 Sandy Road
Seaforth
Liverpool
Merseyside
L21 3TN

ACMR is a new rocketry dealer in the UK:
http://www.active-media.co.uk/~andy/acmr.htm

---------------------------------------
13.3.9 What are some of the rocket clubs in the U.K., and do they have any
problems getting permission to fly their rockets?

From: rosb...@cadence.com (Richard Osborne)
Well groups like AspireSpace (http://www.gbnet.net/orgs/aspire/) and
MARS (Middlesex Amateur Rocketry Society) in Southern England fly
vehicles up to K power without problem. They do always inform the
CAA first, to ensure a NOTAM is issued, but apart from that, there
never seems to be any problem, even with the police. Maybe certain
areas of the UK are more touchy about model rocketry than others.

I don`t think STAAR Research (http://www.gbnet.net/orgs/staar/) has
any problems with their numerous HPR launches in Scotland either.


For people living in southern England, contact SERF:
http://ourworld.compuserve.com/homepages/steve_moores
---------------------------------------

13.4 Rocketry in South Africa

This section is still under construction. The following hobby shop address
has been submitted to the FAQ.

Rocketeers Model rocketry and high power
Box 7032 kits, engines, and supplies
Roodeport
SOUTH AFRICA 1715
+27 (0)11 475 0880

There is a web page for the South Africa Amateur Rocket Club (SAMROC)
organization. This web page may be viewed at:

http://www.samroc.org.za/

This looks to be a pretty complete web page, explaining the state of
hobby rocketry in S.A., listing addresses of rocketry suppliers in the
country, and giving amail addresses for further information. There are
also pictures from SAMROC launches and a launch schedule.
---------------------------------------

13.5 Rocketry in New Zealand

This portion of the FAQ has been archived until the New Zealanders can
agree on what should be stated here. The editor does not know anything
about rocketry in New Zealand, and is in no position to arbitrate
the dispute.

Questions regarding this section can be directed to both:

Lindsay Gordon (lindsay...@stonebow.otago.ac.nz)

Gerry Munden <gam...@iprolink.co.nz>

---------------------------------------

13.6 Rocketry in Germany

Written by Stefan Wimmer (s...@cellware.de)

Germany is well-known for its many legal regulations. Consumer
rocketry is no exception to that rule: rockets, rocket motors and launches
are covered by several laws (Luftfahrtgesetz, Luftverkehrordnung,
Sprengstoffgesetz...). The most stringent legal regulation are concerning
the motors which are covered by the German explosives law (Sprengstoffgesetz,
SprenG). To understand why they are so restrictive you have to know, that
they passed legislation in the 70s during the active phase of the
Baader-Meinhof terrorists (btw. one of their declared aims was to cause
the creation of so many legal restrictions, that personal freedom would
be strangled to a breaking point causing a revolution against the system.
Well, they almost reached the first part....).
Rockets and rocket motors are considered to be a potential base for
destructive devices and therefore limited to useless (unfortunately not
only for this purpose) power levels. As if terrorists bother with model
rocketry stuff - ever heard of an I-powered hand grenade, or such??

-----------------------------------------------------
13.6.1 German Explosives Law

The German explosives legislation is divided into several sections:

The 'Sprengstoffgesetz' (SprengG),
the '1. and 2. Verordnung zum SprengG' (1.und 2. SprengV), and
the according 'Verwaltungsrichtlinien'.

For rocketeers the most important parts are paragraph 27 of the SprengG
and the 1. and 2. SprengV which regulate handling and storage of pyrotechnic
devices. The 'Verwaltungsrichtlinien' are also very interesting because
they define, how the office people will (have to) react to inquiries.

The SprengG divides Pyrotechnic devices into 6 different classes:

- Class I (very small fireworks)
These (eg. sparklers) may be bought and used throughout the year, even
by children. No rockets are allowed in class I.

- Class II (small fireworks)
These are the common end-of-the-year fireworks. May be bought by
adults during the last three days of the year, and may only be used on
31st of December and 1st of January.

- Class III (medium fireworks) and
- Class IV (big fireworks)
may be bought and used only by licensed people (license according to
paragraph 7, 20 or 27 of the German explosives law).
Storage has to be done in approved storage places.

- Class T1 (small technical pyrotechnic devices)
These may be bought by adults and used by people of at least 14 years
(under adult supervision from 14-17) throughout the year. Limitation for
rocket motors in this class is 20g of propellant. That's why German
rocketeers are usually stuck with A/B/C motors.

- Class T2 (big technical pyrotechnic devices)
Everything that is not considered display fireworks and anything too
big to be class T1. For rocket motors this means anything with more
than 20g of propellant AND also clustering and staging of T1 motors.
(!!!). So if you plan to launch eg. an Estes Commanche,
get your T2-license first!

All pyrotechnic devices except class IV have to be approved by the
'Bundesanstalt fuer Materielforschung und -Pruefung' (BAM). In order to get
approved, the device and the contained pyrotechnic compounds have to pass a
number of tests to assure stability in storage, safety in handling and use,
and quality of the products. The manufacturer will have to demonstrate
acceptible quality control practices to be sure that subsequent production
runs of the product will equal the tested ones. From time to time,
additional samples have to be sent to the BAM for quality assurance
verification.

-----------------------------------------------------
13.6.2 German Aviation Regulations

The most relevant parts of the German aviation legislation are paragraph
16 of the 'Luftverkehrsordnung' (LuftVO) (which defines when to ask for a
waiver and what information has to be provided in order to get a waiver) and
Paragraph 37 of the 'Luftverkehrsgesetz' (LuftVG) (which demands that
model aircraft up to 20kg has to have an insurance good for 2.5 mio DM per
accident. If you plan bigger rockets: The next category is aircraft up
to 1200kg and requires a 5 mio DM insurance.)

If you plan to get a distinct area registered as your 'Raketenflugplatz' get
a copy of the 'Richtlinien fuer die Genehmigung von Raketenplaetzen.'
Read it, and decide if you can meet the requirements.

-----------------------------------------------------
13.6.3 What Rockets and Motors can I buy and use in Germany?

Some hobby shops with a good flyers' supply sell Estes and Quest model
kits. There are even some genuine German manufactures whose parts and kits
occasionally show up at stores. Most suppliers and manufacturers sell their
products by mailorder too.

T1 motors:
Currently there is a range of Estes A,B and C motors available at the same
stores. The greatest variety is from Estes. They cost about DM 8-12 for
a 3-pack. A8-3, B4-4 and C6-3 motors are also available from a German
manufacturer (Moog-Nico) and sell for DM 22-35 in packets of 10.
In some places you can also get the brave old HELD1000, which is basically
a C2-0 originally intended for boost gliders. All these motors are
BAM-T1 and can be bought, stored, and used without problems.

T2 motors:
There are several motors listed in the addendum of the German explosives law,
but most of them are out of production (eg. some FSI motors). There are some
remaining HELD5000, but the last batch was manufactured in '88 and
depending on transport and storage conditions, they have degraded by now.
One member of the RAMOG (address in the Club/Address section), Mr. Maurer,
sells a manufacturer-reloadable motor, the BC360. It is a double-base
propellant motor with 360Ns. The (filled) casing is about DM 350 (may have
changed by now) and a refill is around DM 70 plus S&H.
There is also a BC1800, but it is not yet BAM certified.
There are some more motors to come, but they are still in the process of
design and/or BAM certification. Please check with the DERA or the RAMOG for
more current information!

Last fall we (the DERA people) discovered, that the Estes D12-5 has its
BAM-T2 classification, but only when it comes through a certain importer and
with a prescribed German text on the motors and packages (this is part of the
BAM certification and published in the explosives law word by word).
We then found out that this importer is out of busines :-((
After some negotiations we found a pyrotechnician who is willing (kind of
;-)) to take over the importing part. Then we contacted Estes for the
customized (German) motors. Status: Our batch of motors will be
manufactured sometimes in August'96. It will then take some time to cure/pack
and get them to Germany and through the customs. By then we should be able to
calculate the price. Please contact the DERA for availability.

If you wish to get a motor approved by the BAM be warned: It is possible
but costly both in time and expenses.
First you must have a complete list of chemical ingredients of the
pyrotechnic compounds. Try to get that from a foreign manufacturer!
(The author (and others) once tried that with Aerotech - without success.)
Then the BAM needs several sample devices in order to test the stability
sensitivity of the pyrotechnic materials, and the consistency of the
device's performance. Third they need proof (not an affirmation) of the
quality control system of the manufaturer, and that QC is done on a
regular basis by trained staff. If you can't get this, some of the BAM people
want to inspect the manufacturers site(s). They must be sure (by law) that
all subsequently manufactured devices are of the same quality as the ones
submitted for the tests. And remember: YOU will be charged for all expenses
they have. If you got through all that, be aware that the BAM will
occasionally request more samples for further testing to determine if the
motors continue to meet approval criteria.

The whole procedure is no big deal for a manufacturer who sees a market,
but it's hard to do for private people.

-----------------------------------------------------
13.6.4 Clustering and Staging

As mentioned above: Clustering and staging of motors requires a T2 license
in Germany. Even if you cluster/stage 'only' T1 motors!
And don't forget to get the required waiver according to paragraph 16 LuftVO.

-----------------------------------------------------
13.6.5 Can I make my own rocket motors?

Making your own rocket motors is not recommended.
It's completely illegal without the appropriate permissions and licenses.

First of all, you need a pyrotechnics manufacturing license
("Hersteller-Schein"). After you got this, you need a site and more
licenses from several offices (Arbeitssicherheit, Bauamt, Umweltschutz etc.)
before you can start to plan the several separate buildings needed for
storage of the components, different procedures (grinding, mixing, filling,
pressing etc.), and storage of the finished products.
And don't forget about the (in this case very costly) insurance.

All in all, manufacturing your own rocket motors is nothing you would want
to burden yourself with. Even if you got your manufacturer's license,
you are still not allowed to USE the products you made unless they have
got their BAM approval for class I, II or T1/T2!!

Bureaucracy rules!

-----------------------------------------------------
13.6.6 Can I use rocket motors made for display fireworks?

Rocket motors used in big display fireworks usually belong to class IV
fireworks (as everything that is not BAM-approved, such as foreign motors)
and are limited to people with the appropriate license. Even worse:
if you stuff such a motor in a model rocket, it is automatically
considered display fireworks and requires a (costly) announcement to the
appropriate officials like any other display firework.

-----------------------------------------------------
13.6.7 Importing Rockets, Parts and Motors

There is no real problem with importing rocketry stuff from foreign countries
as long as no pyrotechnics are involved. What you have to keep in mind is that
every shipment from abroad will have to pass the customs clearance where
you'll be charged the 15% 'Einfuhrumsatzsteuer' and the customs (5-8%) which
vary on the type of goods you're importing. The author found out that there
is a 'Zoll-Warengruppen-Nummer' 8802 6000 000 for 'suborbitale Raumfahrzeuge
und deren Teile' (suborbital spacecraft) which model and high power rockets
undoubtedly are ;-)) (The author likes the looks at the office he always
gets when the people there look up the number in their books.)
This way you get off with only 5.1% customs (which btw. will be computed on
the whole sum of the bill, including shipping and handling costs!). To ease
the procedure, have the sender glue a copy of the bill to the outside of the
box in an envelope marked with 'Rechnung'. Have him write the
'Warengruppen-Nummer' on the bill too.
Even after adding up S&H and the 20.1% to pay, there are some occasions when
you can get Estes and other stuff cheaper from the USA than you'd ever get it
in Germany. Not to speak of all the HPR stuff which is very unlikely to show
up in a German store at all.

*** BEWARE OF IMPORTING FOREIGN MOTORS!!! ***

Every box from abroad will be opened as it passes the German border. You
might be asked to show your license at the customs office when you try to pick
up your goods. If you don't have a license, then you're in trouble!
Non-BAM-approved pyrotechnics are ALWAYS considered class IV fireworks.
The goods will be destroyed and you will be charged with both the cost
of destruction and a fine. Offenses against the explosives law are considered
criminal offenses, and there is even a chance to go to jail for it!
Foreign dealers will not know about that and send you whatever you order.
BUT IT'S YOU WHO HAS TO BEAR THE CONSEQUENCES!

-----------------------------------------------------
13.6.8 Where can I launch my Rockets?

There are several rules which have to be obeyed:

First, you must be at least 8 km away (as the crow flies, Luftlinie)
from any airport.

Second, you must have permission from the landowner to launch.
(not where your rocket is going to land but it helps to take that into
account too).
It helps to launch from public ground like publically accessible
field paths, because there you only have to ask the next available
representative of the public, who is usually yourself. ;-)
The 1m zone on either side of small streets connecting small villages
is usually considered a public area. If there is no traffic and
enough room to park your car, then you can set up your launch equipment
there too. But take care not to irritate occasional bypassers!

Third, you have to stay underneath the surveyed airspace with your T1 powered
rockets. Usually it begins at 300m AGL but that varies from place to place.
In Germany there are many "Tieffluggebiete" (low flying areas) used by the
military who don't like "missiles" crossing their flight path! Check with
your local "Flugsicherungsdienst" (the German FAA) if in doubt. A good
idea is to buy a 'Luftkarten' of the area in question and check
for restrictions.
If you chose to fly T2 powered birds, you ALWAYS need a "Luftraumfreigabe"
(waiver), no matter how high your rocket is going to fly!

-----------------------------------------------------
13.6.9 Where can I launch rockets with bigger motors?

If you really want to legally get into high power or experimental rocketry,
you first will have to get a license to buy, store, and transport
class IV fireworks. There is no way around this since everything without
any kind of BAM approval (like foreign motors) will be considered to be
class IV fireworks.

Once you are licensed, you must contact a military base, where they may
have some kind of shooting range, and ask the authorities for permission
to occasionally using their range for 'test flights.' Usually, this will
be impossible because of 'duds' (Blindgaenger) laying around there.

If you do get the permission, then you can apply for a waiver
(Luftraumfreigabe) for the dates when you are allowed to fly. Most
shooting ranges will already have a restricted airspace (gesperrter Luftraum)
which only has to be activated for the time of your launches.

If you have made it this far, the you are one of the luckiest rocketeers
in Germany, because the 'normal' explosives law isn't valid on military
properties. But you still need to take precautions that your rocket will
not leave the range. If it does, then there could be trouble again.
And don't forget: posession and transport of non-BAM-approved motors is
restricted to licensed people!

If you are living near Berlin (or are willing to travel for your launches),
you can contact the DERA, since we are already in the process of getting
a launch range on a military base. Negotiations look good so far (09/96)
although there will be a fee.

-----------------------------------------------------
13.6.10 What Insurance do I need?

For T1 powered rockets, you shouldn't need a special liability insurance.
But some insurances explicitely exclude rocketry in the fine print of their
contracts. To be sure check this before your first launch! Ask for inclusion
or change the company if necessary!

T2 powered rockets are considered 'normal aircrafts' and the appropriate
regulations of the 'Luftrecht' rule: Aircraft up to ..kg weight
(ready-to-launch) must have a liability assurance good for DM 2,500,000
per accident. All aircrafts are insured via the "Deutscher Luftpool."
Ask the insurance company about this kind of insurance.

Probably the best alternative is to join a club where the insurance is
included in the dues.

-----------------------------------------------------
13.6.11 Addresses of Rocketry-related Clubs

DERA e.V. RAMOG (Raketen Modellsport Gruppe)
(Deutsche Experimental-Raketen Arbeitsgruppe) c/o Herbert Gruendler
c/o Dr. Hans-Peter Boehme Edenbergen
Saarstr. 19 Talblick 7
12161 Berlin 86368 Gersthofen
030 / 859 997-58 08230 / 1451
or:
DERA e.V.
c/o Stefan Wimmer
Wiesener Str. 23
12101 Berlin
Tel/Fax: 030 / 789 12 97

Dara Raketen Modell Sport Gruppe Deutscher Aero-Club e.V.
V. Schoenfelder Postfach 1361
Koenigswinterer St. 522-524 63131 Heusenstamm
53227 Bonn-Oberkassel
0228 / 45 51 02

Modellflug Club 1990 Raketen-Hobby-Gruppe
Thierfeld-Hartenstein e.V. Vaihingen-Enz
Sparte Raketenflug Karl-Heinz Gulich
Siegfried Goerner Steinhaldenweg 5
Jablonecer Str. 8 71663 Vaihingen-Enz
08062 Zwickau 07042 / 92125
037578 / 6021

Raketen-Modellsportclub Juri Gagarin RMV 82 e.V.
Berlin e.V. Duerenhofstr. 35
Gottfried Tittmann 90478 Nuernberg
Platz der Vereinten Nationen 8 0911 / 46 30 37
10249 Berlin
030 / 426 04 34

Raketen Sport Club Dietfurt Raketen-Sport-Club Muenchen
Christian Freihart Bernhard Irler
Im Kellergarten 1 Sankt-Anna-Str. 19
92345 Dietfurt 8.... Muenchen
08464 / 1428 089 / 22 66 01

Wasa R.V. Raketen Sport Freunde
Peter Wolf Manfred Fronhoefer
Peter-Bernhard-Str. 14 Kelheimer Str. 3a
83329 St. Leonhard 92339 Beilngries
08681 / 895 08461 / 1336

Check out Oliver Missbach's website:
http://ourworld.compuserve.com/homepages/oliver/rockets.htm

---------------------------------------
Copyright (c) 1996, 1997 Wolfram von Kiparski, editor.

Wolfram v.Kiparski

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Archive-name: model-rockets/amateur
Rec-models-rockets-archive-name: rockets-faq/part14
Posting-Frequency: monthly
Last-modified: 1997 September 25
URL: http://dtm-corp.com/~sven/rockets/rmrfaq.toc.html


Rec.Models.Rockets Frequently Asked Questions: PART 14 of 14

AMATEUR ROCKETRY

14.1 DISCLAIMER:

The following information does not constitute an endorsement of
amateur rocketry in any way, shape, or form by the editor(s)
of this FAQ, or the general readership of rec.models.rockets.
Due to the number of requests for information on this form of
rocketry, the following information is provided.
Pursue at your own risk.
------------------------------------------------------

14.2 How do I make my own rocket motors?

NOTICE:

Many among the readership have an interest in this subject, and discussion
threads about amateur rocketry activities always appear.
Even though the name of the newsgroup, rec.models.rockets, suggests that
the newsgroup is for model rockets only, this is not entirely true. High
power rocketry is a favorite topic among r.m.r. denizens. And similarly,
amateur rocketry is also discussed, albeit in a limited way.
However, questions like:

"What should I mix together so that I can make my own rocket motors?"
"Anyone know of any good formulas for rocket propellant?"

are STRONGLY DISCOURAGED. Discussion about rocket motor design and
fabrication is beyond the scope of rec.models.rockets. Most of the
participants of rec.models.rockets buy commercially available model and
high power rocket motors for use in their rockets. Few have the expertise
to instruct you on the intricacies of rocket motor design and construction,
and most likely will not instruct you on rec.models.rockets.
Rocket motor construction is a non-trivial task. It is a task that goes
much beyond merely having a propellant formula to use.
You need to know much more than you might initially suspect, and even
then you might make a mistake and get seriously injured or even killed.
Even knowledgeable professionals have been known to have accidents.
If you are having difficulty obtaining commercially manufactured rocket
motors, and think that you can simply make your own, please think about it
more, and please give these warnings some serious consideration. Inquire
as to the availability of commercially manufactured motors. Check out the
list of manufacturers in Part 2 of the FAQ.

From (bi...@puli.cisco.com)
" I suppose that an article on cheap model rocketry would not be complete
without at least some comment on the sorts of advertisements that read
"build your own rocket engines for only pennies apiece." While I personally
am not the sort of person who would categorically condemn those people
interested in making their own rocket motors, I do feel that model rocket
motors are one of the places where you do get your money's worth. While it
may be possible to build your own motors using only a few cents worth of
chemicals, there is a lot left unsaid. Some of these unvoiced gotchas
include:

1) In order to get to the pennies each price range, you have to buy your
chemicals in large amounts, so your out-of-pocket expenses are high.
2) You have to make or buy various special tools for making the motors.
3) You'll need assorted amounts of safety equipment and test fixtures,
beyond the actual construction tools.
4) You'll need a relatively large land area for your testing.
5) You'll probably be engaging in what the local police will consider
illegal activities, both in making your motors, and in using them.
It doesn't take much of a lawyer's time to cancel out your savings!
6) The finished "cheap" motors are unlikely to have delay or ejection
charges, and will vary a great deal from motor to motor in performance.

"I'm also interested in amateur pyrotechnics, and recently bought a copy of
"The Best of American Fireworks News, Volume 2." There are a couple of
excerpts in there that are particularly telling. One article mentions using
commercial A8-3 rocket engines as a "quick and easy way" to make skyrockets.
This is followed up by another comment that includes:

"I have made rocket engines from scratch for years, but
have just recently discovered that the time savings,
reliability, and better performance of commercial engines
make them a viable alternative."

"These are discouraging remarks for the would-be motor maker, but the most
important reason NOT to make your own motors is implied in item (5) above -
"Model Rocketry" enjoys certain legal exemptions because it has shown itself
to be an exceptionally safe hobby over the years. If you make your own
motors, you are no longer protected under those exemptions - you are no
longer participating in "Model Rocketry". If you happen to have or cause a
major accident, the press won't be clued in to this distinction, so aside
from the people who actually got hurt, the reputation of the hobby will be
damaged, and we'll be another step closer to having model rocketry outlawed."


Have you read Part 1 of the FAQ yet? Here are a few repeat items to
consider:

From Buzz McDermott (buz...@netcom.com)
"Finally, the editor of this document wishes to get on his soapbox for
just one moment and add the term 'stupid rocketry' to cover all those
who attempt to casually produce their own rocket fuel and/or motors
without the benefit of very serious study, and implementation, of the
processes involved and safety measures required. Especially note
that this comment is NOT aimed at serious amateur rocketry
organizations, college level research, etc. End of soapbox."

In summary:
The bottom line is that rec.models.rockets is primarily a newsgroup for
discussing *consumer* rocketry (which covers model rocketry and high
power rocketry). Some amateur issues are discussed, but these are not
the primary focus of the group. Manufacturing your own rocket motors can
be a very dangerous thing to do, unless done properly, and with extreme
care. The odds are you will not make motors that are of any higher quality,
total impulse, reliability, or cost less than pre-manufactured consumer
rocket motors.

It is the opinion of the editor(s) of this FAQ that you should NOT try
to manufacture your own motors. If, however, you insist on partaking
in amateur rocketry, then the editor(s) of this FAQ urge you to get in
contact with an established amateur rocketry group for guidance and
assistance.
------------------------------------------------------

14.3 My primary interest is in amateur rocketry.
Where can I find information about amateur rocketry?

Aside from going to college and earning an aerospace engineering degree,
there are organizations dedicated to the serious pursuit of research and
development in the field of amateur rocketry. The editor
suggests contacting one of the organizations listed below. These
suggestions are not endorsements, and the author of Part 14 of the FAQ
is personally unfamiliar with these organizations.

Mojave Rocket and Technical Society
http://www.mrts.com

Pacific Rocket Society Well-established amateur
1825 North Oxnard Blvd., Suite 24 rocketry association.
Oxnard, CA 93030 Established in 1946.
cybe...@aol.com
http://www.asesur.com/prs

Reaction Research Society Well-established amateur
P.O. Box 90306 rocketry association.
World Way Postal Center
Los Angeles, CA 90009
http://www.rrs.org
------------------------------------------------------
14.4 Amateur rocketry on the Internet

REC.MODELS.ROCKETS

In case you haven't read any other part of the FAQ yet, amateur rocketry
on the Internet IS NOT rec.models.rockets. Read Parts 1 and 14 of
this FAQ.

REC.PYROTECHNICS

Questions related to rocket motor propellant formulation, rocket
motor construction, etc. should be posted on rec.pyrotechnics.
Discussion threads about these subjects always appear there.
Get their FAQ for even more information.

AMROCNET MAILING LIST

The AmRocNet mailing list is for the discussion of all aspects of "amateur
rocket and motor construction". This includes discussions relating to
amateur rocket designs, making motors, safety, laws, events, experiences,
news, reviews, commentary and other items which could be described as of
general interest to amateur rocket people.
To join the AmRocNet mailing list send the following Email:

-----<begin sample Email to listproc>-----

To: <list...@vnet.net>
Subject: .

subscribe amrocnet Your Real Name

-----<end sample Email to listproc>-----


WORLD WIDE WEB


From Tim Patterson (mon...@primenet.com):
I have recently created a new rocketry web page. It has info and links
regarding High Power solids, amateur liquids and other interesting
stuff. Check it out at: http://www.primenet.com/~monoply

How to Design, Build and Test Small Liquid-Fuel Rocket Engines
is a small (66 pages) booklet published by ROCKETLAB in 1967.
As such, it is somewhat dated, but is nonetheless interesting.
You can read it at:

http://www.im.lcs.mit.edu/rocket/

Tom Peregrin's Pyrotechnic Web page
Tom routinely contributes to rec.models.rockets whenever
pyrotechnic issues arise.
http://mercury.aichem.arizona.edu/~tip/pyro.html

Greg Gallacci's Pyrotechnic Journal
http://psychserve.psych.washington.edu/pyro.htm

Blue Sky
a website devoted to composite rocket motor making
http://www.tiac.net/users/bluesky/rockets/

Tom Dimok's Pyrotechnic Web Page
loads of links, information, and advice
http://tad1.cit.cornell.edu/Tom/Pyro/MyPyro.html


------------------------------------------------------
14.5 Manufacturers, suppliers, publishers, and consultants

The following addresses do not constitute an endorsement of
amateur rocketry in any way, shape, or form by the editor(s)
of this FAQ, or the general readership of rec.models.rockets.
Due to the number of requests for information on this form of
rocketry the following addresses are provided as potential sources
for more information. Pursue at your own risk.

Aerocon new and used aerospace hardware,
P.O. Box 432 parachutes, books, liquid motors,
Los Gatos, CA 95031 and more...
(408) 450-0704 Catalog - $2.00

Commonwealth Displays, Inc. Chemicals for solid propellants
12649 Dix
Southgate, MI 48195 Catalog: $3.00
(313) 282-1055
email: hdh...@aol.com
WWW: http://www.commonwealth.net/rockets/cdi.html

CP Technologies Books, videos, and supplies for
4010A South Poplar, Suite 23 building ammonium nitrate
Casper, WY 82601 composite propellant motors
(307) 265-5895 Catalog - FREE (see website)
email: 71137...@compuserve.com
http://ourworld.compuserve.com/homepages/jwickman/homepage.htm

Digatek black powder and composite
Suite 200 propellant formulas and motor
2723 West Butler Drive making information
Phoenix, AZ 85051
71231...@compuserve.com Catalog - FREE

Firefox Enterprises Pyrotechnic supplies, amateur
P.O. Box 5366 rocketry supplies.
Pocatello, ID 83202
(208) 237-1976 Catalog: $3.00
http://bf.axxess.net/pages/firefox/

Gas Dynamics Lab publishes a book on rocket motor
P.O. Box 465 design
Watkinsville, GA 30677
jela...@bellsouth.net
http://personal.lig.bellsouth.net/~jelanier

Journal of Pyrotechnics technical journal on pyrotechnics
1775 Blair Road published twice yearly
Whitewater, CO 81527
(970) 245-0692
71061...@compuserve.com

Prodyne, Inc. Solid rocket motor fuel grains,
P.O. Box 12806 chemicals, processing
Ogden, UT 84412-2806 equipment.
Catalog: $2.00

Propulsion Systems, Inc. Books, software, chemicals, and
Amateur Rocketry Division hardware for composite
P.O.Box 130077 propellant motor design and
Edmond, OK 73013 fabrication.
(405) 478-5806 Catalog - $3.00

Rogers Aeroscience PC software for rocket flight
P.O. Box 10065 prediction includes drag modeling
Lancaster CA 93584-0065 thru the hypersonic regime;
(818) 349-4825 * free info *
email: 70574...@compuserve.com

Rosenfield Consulting Services Consulting service for fuel
1955 South Palm Street, Suite 15 formulations, gov't approval
Las Vegas, NV 89104 processes, etc.
(702) 641-9478 (voice)
(702) 641-1883 (fax) FREE brochure and price list
email: 7362...@CompuServe.COM

RPS Rocket motor kits, tooling,
207 Lewis Drive and info on making rocket
Richmond, KY 40475 motors

Skylighter, Inc. Pyrotechnic supplies
PO Box 480-W chemicals, books, equipment,
Round Hill, VA 20142-0480 supplies, etc.
(540) 554-4543
(540) 554-2849 (Fax) Catalog - $3.00 (USA)
Custs...@skylighter.com (Email) (see website)
http://www.skylighter.com

Systems Solaire Plans for an amateur rocket
4414 Notre Dame motor which utilizes
Chomeday, Laval, Quebec gasoline as the fuel source.
CANADA H7W-1T6

Teleflite Corporation Information and supplies for
11620 Kitching Street making your own rocket motors
Moreno Valley, CA 92387-9978 black powder motor making
David G. Sleeter <slee...@mail.idt.net> Catalog - $2.00

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