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early motor History

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George Gassaway

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Feb 16, 1994, 10:11:00 PM2/16/94
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bi...@glare.cisco.com (William ) writes:
>>Does anyone besides estes currently sell an engine smaller than 18mm x
>>2.75In? I like tiny rockets...

In the US, right now, the only non-Estes motors smaller than 18mm dia is
the Apogee B7 composite motor, which is 13mm diameter (Apogee also has
some 1/4A's and A3-2/6T motors for sale, made by Estes' machines).

As Peter Alway pointed out, there are some motors of various smaller
diameters sold overseas, in the 10-11 mm range, mostly made for FAI
(international) competition. However these are almost impossible to obtain
in this country, due in good part to all the regulatory/red tape hoops
that have to be jumped to get the rocket motor processed thru (such as
the DOT classifying the motor for shipping, doing burn tests, etc.).

Since there have been some messages about what sizes/types of old motors
used to be available, here's a partial list of a lot of motors and types
from various companies in the US: (Of the ones mentioned, only Estes, FSI,
MRC, Quest, and Apogee are around today. Of course there are other rocket
companies in business today but I've mostly stuck to the ones selling
black powder motors).

Estes 18 x 70mm (2.75" long) 1/4A's thru C's
Estes "S" type 'shorty' motors - 18 x 45mm (1.77" long) 1/4A's thru A's
Estes "T" type 'mini' - 13 x 45mm (1.75" long) 1/4A's thru A's
Estes 24mm x 2.75" D motors D13/D12/D11
Estes 24mm x 3.5" E15 motor

Centuri 18 x 70 mm (2.75" long) - 1/2A's thru C's
Centuri 13mm x 2.25? or 2.5"? 1/4A thru B (for a brief period)
Centuri 13mm x 45mm 1/4A thru A (same size as Estes mini's, after the B
mini-motor was dropped)
Centuri 24mm x 2.75" D12 motor (same as Estes)

MPC, Cox, FSI, MRC, and Quest all had/have 18 x 70mm (2.75" long) motors,
some types much like Estes, a few not (MPC had an A3 type of motor, and
Cox had a "D8" short delay motor which was an 11-12 N-sec C6 size casing
crammed with propellant & and a bit of delay+ejection).

MPC 13mm x 2.25" "m" (mini-jet) series - 1/2A3, A3, and B3
(MPC got out of rockets in about 1973, but you can still find some of
their plastic fin units, nose cones, and adapters in the Quest line of
kits. The molds and other items were apparently bought at an auction when
AVI was liquidated around 1979).

AVI - same 13mm x 2.25" mini-jets as orginally made for MPC, because AVI
was run by Mike Bergenske who'd developed and obtained the MPC engine
making machinery when MPC dropped rockets. AVI made a number of unique
contest oriented black powder engines from late 1975 thru approx. summer
1978, called "Gold Series":
Micro-jets - approx 8 mm diameter, 1/8A (!), 1/4A, & 1/2A sizes, length
varied with motor type.
D6.1 motor - 18mm dia, 4.0-4.25" long (3.5-4 sec burn, NICE)
E11.8 motor - 24mm dia, same length as D6.1 (3.5-4 sec burn, NICE)
* the new Estes E15 reminds me a LOT of the old AVI E11.8
E23.8 and F24 motors - 35mm dia (Can't recall lengths, due to the large
diameter they didn't need to be as long as FSI E60 and F100's are)

Arrarently at least one MPC engine making machine, later used by AVI, is
still cranking out engines today. In other words, it's probably not a
coincidence that the Quest motor nozzles look exactly like the MPC/AVI
motor nozzles did.......(curved, not sharp angled).

FSI - well, nearly the same motors they had in the 70's are still in their
catalog today (their odd-diameter 21mm motors A-E power, and their 27mm
dia E & F motors). Though they finally did come out with 18 x 70mm sized
motors too.

Centuri also had Mini-Max E & DF sized black powder motors, later dropped
in favor of the Enerjet line of composite motors (Enerjet having been
developed by Irv Wait from Rocket Development Company).

And there was a company in North Carolina called SEMROCS in the early
'70's, a couple of their motors were 3/4 power B (3.75 N-sec) and 3/4
power C (7.5 n-sec) types, in 18 x 70 mm cases.

I'll leave the various other composite rocket motor companies that sprang
up from the mid-late 70's (SSRS/Crown, Composite Dynamics, etc.) till
today for others.....

Oh, there was at least one other "big engine" black powder motor maker,
Prodyne from the 60's. I wasn't around then, they made motors up to F
size.

Somebody probably has info on a lot of this stuff, or at least several
people as a group would (I probably still have the AVI specs somewhere).
It might be interesting to compile an accurate listing of all the old
companies and engines sometime.
And then there's some who have engine collections, Bob Kaplow may be
reaching for some AVI "gold series" motors and calipers at this very
moment.... <G>

Oh yeah, there was also this rocket company called Model Missiles
Incorporated (MMI) from 1958 - the original rocket company - started by
Orville Carlisle and G. Harry Stine. Originally Orville made his own
motors that were 13mm in diameter, but he couldn't mass produce them. They
found a fireworks company that could make them but the fireworks company
wasn't set up to make anything 13mm in diameter. But they did have a "buzz
bomb" paddle spinning helicopter fireworks piece with a paper casing that
was..... 18mm in diameter. This became the "Rock-A-Chute" motor, "Type
A", approximately an A5-2 (Paraphrased from one of Harry Stine's "Old
Rocketeer" columns).

---
This copy of Freddie 1.2.5 is being evaluated.

Mark Jilson

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Feb 18, 1994, 8:52:15 AM2/18/94
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In article <4000.39...@the-matrix.com>,
george....@the-matrix.com (George Gassaway) writes:

>As Peter Alway pointed out, there are some motors of various smaller
>diameters sold overseas, in the 10-11 mm range, mostly made for FAI
>(international) competition. However these are almost impossible to obtain
>in this country, due in good part to all the regulatory/red tape hoops
>that have to be jumped to get the rocket motor processed thru (such as
>the DOT classifying the motor for shipping, doing burn tests, etc.).

One of the COSROCS members has a catalog from a company in Eastern Europe,
Slovenia or something but not Czechoslovakia, that has 11mm enigines. He
ordered some and they came in a plain brown box with no markings !! The
lastes NAR manufacts list showed up at my house recently and a Canadian
company is listed as having some 11mm enigines. I wonder if someone has
plans to distribute these in the US also. From all reports these 11mm
engines are very nice and have very good performance.

--
Mark D. Jilson - Digital Customer Support Center
Colorado Springs, Colorado

NAR #54156, COSROCS -- In Thrust We Trust

Xiaoyi Eve Zhang

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Feb 18, 1994, 10:21:05 AM2/18/94
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In the early sixties, I bought my first model rocket mail order. It had
Rock-A-Chute engines, plastic fins, and two stages. I don't remember if
it was MMI, though the name rings a bell. The company also sold motor
tubes, tools, and instructions for making your own rocket engines. One
kind used charcoal-enriched black powder. The other kind used KClO4 and
red gum. The first kind always blew up. The second kind never lifted.

Have I got the right company, here?

-Larry C.

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