SCAT ELectronic News 8 September 1999

SCAT ELectronic News 8 September 1999

Table of Contents
=================

Sawing Carbon Composites - Mattes
Seen at Lost Hills
Kudos - Achterberg
Mr Clean - Thorkildsen
Reaction to Pim Ruyter idea - van Dijk
Wobbenking - Hines
Wobbenking - Schlosberg

Sawing Carbon Composites
========================
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Roger,

I am getting setup to build some new models and would like to use my
band saw to cut the carbon composite materials such as for the spar caps
and trailing edge. I have a Sears three wheel saw which has a variable
speed DC motor whose minimum speed is 300 fps. I was considering the
use of a carbide grit coated blade but am not sure if this is the
correct approach.

Does anyone out there have any experience with this and what would they
recommend? Also would be interested in what blades would be best to
rip balsa while providing a smooth, ready to glue surface.

Does anyone know of a source for custom band saw blades? I have tried
a few places on the net and have not received any replies.

Thanks,

Bob Mattes


[ Bob, I do not know, but I'm sure that some readers do. Did you
talk to your carbon supplier ?]


Seen at Lost Hills
==================

Matt and Gail Gewain were at the San Diego Orbiteers meeting, taking
a shakedown run in their new travel trailer. Matt was not flying F1A as
he had not touched in models in a year while building CST's new 4800 sq ft
facility. Gail says that they will be open some Saturdays so if
you want a take run to Tehachapi and see what's new in Composites
you're welcome. Look at the CST Web Site www.cstsales.com. Suprisingly
Matt was not hanaging out with the F1A guys, but with the F1C. Matt
flew F1C years ago with Al Bissonette and rumor has it he has bought
some new bits and pieces. It will be interesting to see what he
comes up with [Did Doug Joyce talk you into a canard ?] Matt has
lots of innovative ideas, his 'spiral bunt' [my term!] of turning with
rudder or wash at the end of the bunt action is just starting to
be used by others.


Also at the Lost Hills meet in a 'new set of wheels' was Al Heinreich.
Unfortunatly Al's wheels were a wheel chair. Al is the chief man at
Aerodyne, a leading supplier in traditional modelling stuff. Al
just moved out of Orange County to Hesperia. The wheel chair is
the result of a little ladder accident as part of the move. Al
take his mobile hobby shop to many SAM and nostalgia type events. Hope
he back on his feet real soon. I do not have his
new address and phone number but Al's not that into nostaglia that
he does not have e-mail This email address is being protected from spambots. You need JavaScript enabled to view it.


Kudos
=====

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Hi Roger;
There has been many discussions on how to move free-flight forward into
the next millennium. What and how to do it?? To start with we need more
people with the vision of George Batiuk. He has almost single handed lay
the start of foundation for the development of a junior program. It was
something that I thought to be a waste of time and energy and I am happy
to say that he has proven me wrong. We need more people like George all
over the country and around the world to carry our sport into the
future.

A corporation,AAES, has been started, that will help George achieve
his vision. The purpose of AAES is to acquire flying sites all over the
country by purchase or lease in all regional districts in the US. to
make available areas to which free-flight
models can be flown. One thing Muncie has shown us is that if an area is
provided for free-flight and models are available, kids will do this and
have a whale of time in the process. The AASE has the National
Engineering Society on board using free-flight as a spring board to
create interests in developing the youth of today, into engineers of the
next millennium. There is an unbelievable shortage of engineers now and
it is only going to get worst and to this end, the NES sees the
tremendous upside in free-flight aeromodeling. This vision of creating a
new wave of future engineers belongs to Walter Scarborough and he
believes free-flight is one way of fulfilling his vision.
The many facets free-flight and aeromodeling offer, make it a good
approach to realizing both George and Walters' visions of what can be!!!
In free-flight you have design, drafting, structural problems,
metallurgy, patterns, molds, mathematics, composites, and on and on. It
alone encompasses so many variations and different
paths to a whole realm of engineering fields it boggles the mind!!

My hat is off to George for taking on a project that I believed
impossible and I now believe can be achieved. And the same to Walter who
has started the process to make it happen. Thank you both and I am sure
many more flyers will come on board in the near future to make our sport
a viable and growing group of future flyers and engineers that will
carry us into the next millennium. Thanks Again!!
Thermals,
Michael Achterberg


Mr Clean
========
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Hi Roger,

Your comments on DeShields brought a chuckle to me. It always amazes me
how Bob DeShields and Randy Archer can look so clean at a contest and
the rest of us gas flyers look like we have been playing in the dirt. I
think they must wash a lot and do shirt changes or something while the
rest of us are trying to throw up maxes.

Thermals,

Terry Thorkildsen

Reaction to Pim Ruyter idea to include the origin of models in the result list
==============================================================================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.

Roger and other scat-members,

I totally agree with Pim Ruyter about including the origin of the models
in the result list. We can not demand people to make there own models.
Still our sport is not only about flying, the making of the models (the
knowledge off mechanics, aerodynamics, electronics, etc) is of just as
much (if not more) importance as the flying it self.

Including the origin of the models on the result list meets all arguments
I heart in the BOM discussion. More people can participate in
competitions, still we don't neglect the effort necessary to create a
flying model. In other sports like F1, sailing, and even hors-riding the
same is done! I really think we should discus this option seriously,
else I think we will lose the essence of our beautiful sport!

Regards,

Maarten van Dijk.


Fw: Wobbeking stab section
==========================
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Hi Jim,
Hope you folks are well and happy.
I looked thru several years of FFN issues to verify my recollection:
there are several different versions, varying in thickness from 7 to 9%.

All have common features: blunt L.E. raised ~2% above bottom datum
surface, 20% rounded H.P. then straight rear top to T.E.
So just draw your own preferred thickness! It won't matter a bit!
P.S: I don't personally like it; prefer AL-33 stab section.
Ciao
LEE


Wobbenking
==========
Sender : This email address is being protected from spambots. You need JavaScript enabled to view it.

Roger,

Following Jim Bradley's query, I am sending you the coordinates of
Wobbenking stab, that Gerhard mailed me a few years ago.

% Lower Upper
0 1.6 2.2 (This is not a mistake!)
2.5 0.1 5.1
5 0 6.25
10 0 7.33
15 7.93
20 8.0 (maximum thickness)
25 7.83
30 7.6
40 6.7
50 5.8
60 4.9
70 4.0
80 3.1
90 2.2
100 0 1.3

In my opinion, this section is the best available all-around stab section=

for Nordics and probably Wakefields as well. Thinning it or sharpening the
noise reduce its effectiveness as a stabilizer. My preference is use a
light D-box to about 15% of the chord to attain the aerodynamic features of
the section. Minimal leading edge-stabs - reaching to 5% , form a
completely different section. What matters in stabland is the shape of
the slope the Cl curve relative to the angle of attack around the gliding
point, which is typically at a Cl of .1 for a CG at 50-55% of the wing.

The thickness of the trailing edge depends on the type of construction in
question. Reducing it to zero will encourage warps over time.

Aram



......................

Roger Morrell