SEN 767 - 22 Dec 2002

SCAT Electronic News 22 December 2002 issue 767

Table of Contents
Rubber variations - Schroedter
Epoxy foaming agent - Linkosalo
Jr F1P development program - Parker
A New Tradition - Lorbiecki
Curvilinear Answers - Joyce
XMAS Stuff - Brun

Rubber variations
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There has lately been a lot of criticism published in the SEN about the
inconsistent batches FAI Rubber and of the variations within the
batches. I'm sure that John Clapp would like to sit down and write a
detailed explanation of why these variations cannot be completely
avoided, but he simply does not have the time. Since I worked with the
old factory buying Champion Rubber from 1983 up until 1994, I am
familiar with the causes of the variations.

We all would like every batch to have the same high energy return. But
the basic ingredient is latex and latex come from trees. We are like the
vintner would love to have his vineyard produce estate quality wines
year after year. But every year the moisture, temperature and nutrients
vary. Some years the wine is superb, in other years it is not as good.
The same holds for the latex used in our model strip.

Now what about variations within batches? When I placed an order back
then it was always for 1000 pounds. Trimming losses reduced that to
where I would receive between 7 and 8 hundred pounds. Like any recipe,
the ingredients had to first be combined into a homogeneous mixture.
This was done in mills. But the mills could only properly mix 250 pounds
of ingredients at a time. So what was sent to me was really 4 batches,
even though what went into the autoclave was a roll that weighed more
than 1000 lbs. .

The rubber was vulcanized in a microwave autoclave. Here was another
source of variations: It was impossible to attain a perfectly uniform
temperature throughout the roll! Now the numbers I have given here must
be different with the present factory, but certainly the basic
procedures are the same.

Many modelers believe that the factory keeps the rubber strip in stock,
so when John places an order, all the factory has to do is ship it to
him. This is far from the truth. It is only after an order is received
from John that they order the ingredients! Oh yes. There sometimes are
small quantities of left overs from previous batches the are first used.
So it will take typically about 6 to 8 weeks for John to receive an
order. One huge advantage for buying from the current factory is that
they are willing to talk about "energy return and how to improve it".
This topic was off the table as far as the old factory was concerned.

I have just one final thought: Winning is a lot more than having the
best rubber. Long ago Lothar Doring told me he never worried too much
about how good his rubber was. He was mainly concerned with having his
models trimmed to perfection and, above all, picking the right air.
Lothar was the F1B World Champ in '81 and '83.

George Schroedter

Epoxy foaming agent
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I used to have this stuff, made by Ciba-Geigy (in Switzerland I think?),
Treibmittel DY 652 Epoxy Foaming Agent. Handy stuff when making F1B prop
blades, where you needed some filling ability of the epoxy between the
carbon skin and Rohacell core. Unforrtunately my batch has solified in the
bottle, and reply of the local importer was that they only deliver it by
gallon... Any ideas of similar products, and places that would sell it in
smaller quantities?

Season greetings to the readers of SCAT,


Asking the SEN crowd
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Hello out there in SEN reader land.
After some friendly prompting I am endeavoring to write 'The Sweepette
Story' and need some help from the global
research files out there!
What I am after is the Bob Meuser column in Model Aviation
with the Sweepette 6 drawing and write up, circa 1975.
If one of you find it, will you kindly copy it and send
to: Lee Hines, 376 Magnolia St, Costa Mesa, CA 92627

In addition, should you think of any related Sweepette
incident or comments, which I might include, feel free
to send them as well, via any method you care to.

Thank you very much,
--- Lee Hines
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Jr F1P development program
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F1P Letter #2 12/20/2002

I had a interesting discussion with Bob VanNest that has caused me to
reconsider the direction of the Jr F1P development program. Let me start
with my basic motivation and Goal.

Goal-field a full 2004 Jr W.C. power team-Four per the current proposed rule wo
uld be great!

Motivation-If the 2002 Jr Team had a third power flyer, USA would have likely w
on team Goal. Five, two minute maxes with a ½A model would have done it. It is
likely that Austin G and John L will return with their high performance F1J's.
Who wants the other two team spots?

>From my Jr Team Committee perspective, I felt we had not done an adequate job
of promoting the Jr F1J program in 2001. The erroneous belief was Austin's 20
00 Jr W.C. win would provide the motivations for other Jrs and their families
to get involved. In retrospective, I think that Austin's, high performance
F1J intimidated the existing 1/2A families.

So, perhaps a Cyclon on the front of a scaled down, lighten up 1970-80 F1C
with a three function timer, folding prop----- would be just as intimidating.

Should we focus on putting together a scaled up Starduster 350, Ram Rod etc
with a less expensive engine? Would this be a better approach to attract
some AMA FF families into Jr FAI? Once in the program, would these flyers
be self motivated into higher performance F1J ?

Please provide feedback. Forward this to any interested parties. I'll collect
the input for about a week and let everyone know the go-forward plan.


Jim Parker

PS. I am asking Jim O'Reilly to make a recommendation of the current power des
igns he has on CAD that could be easily scaled to meet the F1P rules and there
fore could currently be provided to interested parties.

[ Jim - while I hestiate to make this recomendation as it may seem
a little obvious or give strength to the conspracy theories -
how about #18 from the presidemt of the CIAM's past?]

Editorial observation

Jim - it seems that we - the FAI FF community did not follow our rules
with the F1P and we are in danger of hurting those we sought to
benefit. It appears that there no current F1Ps available ? so
we are asking juniors to launch out with un proven designs.

So to fix the situation the CIAM Bureau makes the decision for the
Junior Euro Champs to permit F1P and F1J.

Now we are trying to decide what to do for the World Champs. It
would seem that the Bureau has some obligation to commit right away
that the position will be. Because of the nature of the
World Champs the selection process is more varied so
additional consideration has to be given. For example
you could 'encourage' epople to particpate with simple 'F1J'
models only to find the Bureau decided not to permit them al all.

Back to the original issue of how to help Juniors particpate.
I do not believe that the Junior would be initimiated by the
hot engine or even by Austin Gunder's performance. I think that
the hot engine is a motivator. At that age I only had an ED Racer
getting an Oliver Tiger would have been a motivator for me. To particpate
in a World Champs it is a big commitment. There are a lot
of unknowns beside the hot engine - in particular
for Juniors in the US- travel to foreign country when they
probably have not even competed out of state. Although the
new selection program to make them take part in the Nats
will either kill this one or cure it.

It seems to me that the important part of the program is the mentoring.
If we look at both Austin and John from the last World Champs
they had the support and help of their parents and some good
advice from serious sportsmen. I look at the Juniors successfully taking
part in other classes, they too have that kind of support
and the same personal commitment as Austin and John.

My preference is for your original program. The hot engine,
strong mentoring and 'standard' F1P model. We need to understand
what the CIAM will do.... and some power flyers need to do
some research, building and testing to help the Juniors.

A New Tradition
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I am sitting here at my computer, after having a brand new titanium knee
put in. I read the last few SCAT newsletters and noticed that someone
asked about collapsible streamer poles. Seeing that I have a lot of time
to ponder the world, my thoughts went back to the Junior World
Championships and the thermal pole that John used. It was an old cane
pole that we had cut down to two 46" lengths, so that it would fit in
our model box. This pole had been with us for a few years and had quite
a few miles on it.

Well, as the WC ended, the Gunders and us continued their tradition of
visiting the flying field just before leaving the country. Craig,
Austin, and Taylor slowly walked out to the runway, reminiscing about
what had taken place the past few days. John and I followed. We felt
that we needed to have some tradition also. So, with our cane pole and
mylar streamer in hand, the kids went towards the middle of the field.
After a quick ceremony, they planted the pole into the hard Slovakian
ground. As the mylar flashed in the sun, we felt that this symbol of
free flight would be there for others to ponder. What better way to end
the contest of our dreams.

So, hopefully we will be able to leave another cane pole in France in

John and John Lorbiecki

Curvilinear Answers
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A and B can not be calculated with the information given, but I can
the difference. A shoud be .13 seconds longer for the gear and the increase
in height will be 14.4ft. B will be the same.
Doug Joyce

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To All our Friends throughout the world

We want to wish you a very Merry Christmas (Joyeux Noel!)
and hope the the New Year will full fun flying , fun gatherings and
many maxes for all of us!
Bonne Annee a vous tous.

Pierre & Sylvia Brun


Applogies to all I have not replied to or things I should have
published or e-mail address corrected but so much stuff
and so little time ....

Roger Morrell