Scales for Glider Weighing
Paul Remde
I've been trying to find a good scale system for weighing gliders at the
local gliderport, and at local soaring contests. It may also be used to
weigh other aircraft.
So far I've found a very nice, but expensive solution from a company called
Intercomp. It comes with 3 pads that are only 2 inches tall. They are 15" x
15" x 2". They are connected electonically to a display terminal which can
calculate weight and balance numbers automatically. It comes with ramps
which would make it easy to roll gliders up onto the scales. Each pad can
measure up to 1500 lb. The price is $2,494. (including the ramps) or $1,496
without the ramps. It would be $1,929 with only 2 pads and ramps and $1,595
with two pads and no ramps.
I have scanned their brochure and quote and made it available at:
http://www.soarmn.com/soaring_files/glider_scales.pdf It's a large 1.7 MB
file.
I am not trying to sell scales. I am not connected to the company that make
the scales or the company that gave me the quote. I'm just wondering if
anyone has found anything similar or less expensive.
I like that the pads are low to the ground. I hate using the large "grain
scales" that seem to be commonly used because they have large arms that
could easily damage a glider if it slipped. I don't need the electronic
readout or weight and balance features, although they would be very nifty.
I'm thinking of trying some fund raising with local pilots to pay for it.
Any thoughts?
Paul Remde
Ventus b
Minneapolis, MN
Sam Fly
<paul....@worldnet.att.net> wrote:
Paul,
I have been looking for the same type of scale for our club, Texas
Soaring Association. I have a quote for a set of 3 ACII-4.5K for
$1995.00 and the three ramps $ 499..00 plus freight from Minneapolis.
Are these the same scale that SRA uses for contest, Nationals etc.
If we can get a better deal by purchasing two sets, I would be
interested in saving the club some money. Let me know.
Sam Fly
Doug Hoffman
$14 for a couple of bathroom scales at Target. I used some
leftover 3/4 ply on top of both scales for the main wheel.
Scrap wood for small ramps. I calibrated both scales in
the range of use by weighing myself + ballast on the
bathroom scales and then on medical scales.
But my setup is only good for up to a 600 pound empty
glider. You need something more rugged as well.
-Doug
In article <WZmz6.12977$RF1.9...@bgtnsc06-news.ops.worldnet.att.net>
Paul Remde
I just noticed a mistake in my original post below. I'll restate the prices
more clearly and fix the error:
Intercomp Model ACII-4.5K Aircraft Weighing System
System with 3 weighing pads
$1,995 - 3, 1500 lb pads and readout
$ 499 - ramps for 3 pads
$2,495 - Total
or
System with 2 weighing pads
$1,595 - 2, 1500 lb pads and readout
$ 334 - ramps for 2 pads
$1,929 - Total
I think I would go with all 3 pads so that they can be used for our club
towplane and be lent out for a small fee for other aircraft.
Now... I'm not saying that I can afford either system. I hope to be able to
get local pilots to make donations to a scale fund.
It looks like Sam Fly may be interested in checking on a
FYI the company that makes the scales is:
Intercomp
14465 23rd Ave N
Minneapolis, MN 55447-3438
763-476-2531
1-800-328-3336
www.intercompco.com
acs...@intercompco.com
Eric Peterson - Sales Manager
I received my quote from the following company:
Berne Scale Company
2200 Edgewood Ave. S.
Minneapolis, MN 55426
952-544-2422
www.bernescale.com
Howard Sorenson - Sales
Good Soaring,
Paul Remde
"Paul Remde" <paul....@worldnet.att.net> wrote in message
news:WZmz6.12977$RF1.9...@bgtnsc06-news.ops.worldnet.att.net...
Paul Remde
It looks like a didn't finish my post below. The last part should read:
It looks like Sam Fly and the Texas Soaring Association may be interested in
seeing if we can get a discount on buying several systems. Is anyone else
interested?
Paul Remde
"Paul Remde" <paul....@worldnet.att.net> wrote in message
news:xOuz6.11913$rk4.9...@bgtnsc04-news.ops.worldnet.att.net...
Paul Remde
That's exactly the same price I was quoted for the same system.
I'll let you know if I get close to buying and I'll see if we can get a deal
by purchasing two sets at once.
And maybe I can help you with the freight from Minneapolis. I live in the
Minneapolis area, so I'll pick yours up when I get mine. Then I'll put it
in the back of a two-seater and try to meet you half way. Although, right
before take-off I'm sure some club member would pull the scale out and hop
in himself.
Thanks,
Paul Remde
"Sam Fly" <sam...@gte.net> wrote in message
news:3acdebb...@news.gte.net...
Quietpilot
make me one. The pad is 24 x 24, had an 880 pound limit and came with a ramp.
Same company also makes scales for Indy cars, race horses and such.
My cost was $1100 for the one scale, and it was worth every penny. Gets used a
LOT too.
Good soaring!
Mark G
San Diego
Steve Pawling
http://www.longacreracing.com/catalog/catlist.asp?catid=1
I have a couple sets at work and they are excellent. Also check out their tire
air pressure gauges and other neat stuff.
Cu skies,
Steve
In article <WZmz6.12977$RF1.9...@bgtnsc06-news.ops.worldnet.att.net>, "Paul
says...
Wolfgang Hofmeister
lot of money...
Just had to weigh my glider and went to a shop which rents scales. I payed
35 bucks for a whole week for a calibrated scale with a maximum load of 700
pounds.
For 2000 US$ I can rent it for the next 45 years once a year and allows my
whole club to weigh all their gliders.
Best regards, Wolfgang
(ASW 24e)
Vienna, Austria
"Paul Remde" <paul....@worldnet.att.net> schrieb im Newsbeitrag
news:WZmz6.12977$RF1.9...@bgtnsc06-news.ops.worldnet.att.net...
Paul Remde
I've created a web site to try to get local pilots to donate to a "Glider
Scales Fund". The scales would be available for use by MN soaring pilots.
http://www.soarmn.com/gliderscales.htm
--
Paul E. Remde
e-mail: pa...@remde.net
Homepage - http://www.soarmn.com/paul_remde/
Soar Minnesota - http://www.soarmn.com
Soaring Links - http://www.soarmn.com/soaring_links.htm
Minnesota Soaring Club - http://www.soarmn.com/msc/
Stanton Sport Aviation - http://www.soarmn.com/stanton/
Soaring Sensations - http://www.soarmn.com/soaring_sensations/
"Paul Remde" <paul....@worldnet.att.net> wrote in message
news:WZmz6.12977$RF1.9...@bgtnsc06-news.ops.worldnet.att.net...
Caracole
> Hi,
>
> I've created a web site to try to get local pilots to donate to a "Glider
> Scales Fund". The scales would be available for use by MN soaring pilots.
> http://www.soarmn.com/gliderscales.htm
The following is in 1lb resolution.
http://www.longacreracing.com/catalog/item.asp?id=693&catid=1
Catalog : Computerscales
Computerscales Series M (budget) - 72585
(click image to enlarge)
Price $1,098.00 (add to cart)
Using our newest 12 x 12 1000 lb capacity pads for lighter weight cars.
Great for IMCA cars, Legends, Dwarf, Mini Cup, Karts, road racing Formula
Ford
2 line display shows all 4 wheel weights and any % you want.
Comes with molded carrying case to protect electronics
Crush resistant 18 ft Red cables with heavy duty AN connectors
12 x 12 pads with HD 4 bolt load cells
Battery & charger, 1 year limited warranty
M Eiler
Sam Fly
wrote:
The 1000 lb pads are priced great, but a standard class glider full of
water with pilot and chute, will weigh more than 1000 lb on the main
wheel exceeding the limits of the scale. An open class can and will
also exceed the limits.. The ACII-4.5 looks like the only scale that
will fit the mission for all gliders and tow planes... An Piper Pawnee
will weigh in at about 1500-1600 lbs with the hopper removed and you
really need three pads for an accurate weigh in.
I have used bathroom type scales for many years and note the tail
wheel can vary 1-3 lbs which is not adequate for a CG calculation when
trying to compute for the aft limits
Sam Fly
R Pfiffner
pads for the main, one for the tail and
have a extra one for ???
dick
"Sam Fly" <sam...@gte.net> wrote in message
news:3acff21d...@news.gte.net...
Philippe Athuil
From what I understand open class twin seaters maximum gross weight (Nimbus
4D @820kg =1760 lbs), will exceed the 1500 lbs of the pads you are
menttionning.
Do you think you might need a 1000kg pad (2200 lbs) instead to cover all
the bases?
"Sam Fly" <sam...@gte.net> wrote in message
news:3acff21d...@news.gte.net...
Doug Hoffman
>I have used bathroom type scales for many years and note the tail
>wheel can vary 1-3 lbs which is not adequate for a CG calculation when
>trying to compute for the aft limits
1 pound not accurate? Wow. Your bird must be *extremely* sensitive
to cg. Are you also careful not to shift your weight around while
in the cockpit?
-Doug
Sam Fly
<dhof...@oakland-info.com> wrote:
Doug,
If you have ever done a weight and balance on a glider, the bathroom
scales end up on the tail weight, which will weigh 45-70 lbs... One
pound with that long a moment can make a big difference.
Sam
Paul Remde
I'm still leaning toward the ACII-4.5 scales like Sam. The 1500 lb pad will
work for 99% of all the gliders we weigh and all towplanes. We don't have
any open class two-seaters here in MN yet. If someday (I hope, I hope) have
a DuoDiscus that I want to measure when it's full of water, I'll use the two
1500 lb pads with a bridge and still have one left over for the tail.
Good Soaring,
Paul Remde
"Philippe Athuil" <p_at...@ix.netcom.com> wrote in message
news:9aq1rd$ngc$1...@slb3.atl.mindspring.net...
Duane Eisenbeiss
--
Sam Fly, sam...@gte.net writes:
... 1-3 lbs which is not adequate for a CG calculation when
> >trying to compute for the aft limits
*****
> 1 pound not accurate? Wow. Your bird must be *extremely* sensitive
> to cg. Are you also careful not to shift your weight around while
> in the cockpit?
>
> -Doug
*********
Sam is correct. A 1 pound error in tail weight can amount to an appreciable
error in CG calc. I am sure that he is assuming that CG is calculated by
knowing the total weight and weighing the tail only for the CG calculation.
Duane
Doug Hoffman
I cranked the numbers through for my 15 meter 525 lb (empty)
glider and a 1 pound error at the tailwheel could cause the
cg (calc) to shift from 40.11 %mac to 40.84 %mac. It seems to me
that if your glider changes from "OK" to "dangerous" with
that small a shift you should be starting at around 35%
and then *flyin* the plane. Let the glider tell you how
far back to go as you incrementally work the cg aft.
By the way, the bathroom scales technique I use is taken
directly from the designer's example of how to do it.
The designer is Dick Schreder and the technique was published
in Soaring some years ago.
Safe soaring does not *have* to be overly expensive.
Also, a shift of the pilot in the cockpit of less than 0.5"
combined with a weight change of 4 lbs. will yield a similar
shift in cg. Crank the numbers and quantify rather than
using subjectives like "large" or "appreciable" change..
-Doug
In article <IDuA6.37837$DY.14...@news1.mntp1.il.home.com> Duane
Eisenbeiss, eisen...@home.com writes:
>Sam Fly, sam...@gte.net writes:
>... 1-3 lbs which is not adequate for a CG calculation when
>> >trying to compute for the aft limits
>*****
>> 1 pound not accurate? Wow. Your bird must be *extremely* sensitive
>> to cg. Are you also careful not to shift your weight around while
>> in the cockpit?
>>
>> -Doug
Bob Kuykendall
about co-op scale purchase]
At 09:40 10 April 2001, Doug Hoffman wrote:
>Safe soaring does not *have* to be overly expensive.
Amen.
One thing that I'll chip in with here - I'd far rather work with a year-old W&B done with bathroom scales than rely on a ten-year-old W&B done on fancy-schmancy digital scales.
Of course, any time those digital scales are handy, you should run not walk towards the opportunity to use them. If they're there on the ramp like for a contest weight sampling or such, it only takes a couple of minutes to get the ship on them and levelled and get the numbers. Once you've got the raw numbers, you can work out the arms and moments of the wheel locations at leisure.
But If the good scales aren't available, I think that numbers obtained from bathroom scales can be a lot better than old numbers or no numbers at all.
A couple of years ago I had the dubious privilege of flying a 15-meter ship at a CG location of somewhere around 45% MAC. According to the placards, I was right around the 36% MAC. However, that would have been before the oxygen system, aft battery box, and the refinishing/repainting of the aft fuselage. It was an interesting if not pleasant flight.
Of course, mea culpa and my bad for not delving further into the W&B numbers. It was a free flight in a borrowed ship, and I thought I knew what that horse's teeth looked like.
These days, my general recommendation (see my article on first flights on Wayne Paul's Schreder Sailplane Designs site) is to either validate the W&B before first flight, or at very least duplicate the loading conditions under which that particular ship has been known to fly safely.
But anyhow, lots of things happen to sailplanes in the decades that seem to pass between actual weighings. People add stuff and subtract stuff. They break things and they fix them. Mice and wasps move in and then vacate, leaving their turds and nests behind (but thankfully not trying to claim their cleaning deposits). Things get filled with bondo and painted.
If you're careful and resourceful, you might be better off using the K-mart bathroom scales than to wait five or ten years to do a W&B on accurate-to-the-ounce scales. In my limited experience, bathroom scales _are_ prone to errors of a variety of magnitudes. However, (again in my limited experience), these errors are generally quite linear, and therefore easy to correct for. Certainly, the things you know about are much easier to correct for than the things you don't.
Bob K.
www.hpaircraft.com
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