Paul,
A group of us here in southern Maryland are doing the very same thing. We
are using a rather tired looking combat foamie, a Studio B Foaminator,
loaded with some serious rocket propulsion. I don't know if this has ever
been done before, probably has, but we are having a blast. Flight testing
began during lunch breaks. Our first launch was with a D-12 engine. This was
rather disappointing-very under powered. Since then we have worked our way
up to E's, F's and finally a G-40 motor. This is about a large as you can go
without an explosives licensee. Each motor letter increase, doubles the
specific impulse. Each time we stepped up to a larger motor, I fully
expected my "Rocket Foaminator" to disintegrate, never to be seen again. So
far it hasn't. This thing is just a dot when reaching the apex. Hang time is
reasonable. All the fun is in the fire and smoke. Hard to imagine this
glider, made of foam and tape belching fire out its belly, powered with up
to 18 pounds of thrust! This thing easily exceeds 125 mph. DS one way. Up!!
The Foaminator is 48" span, straight mid wing ship, with a Corplast V-tail.
Epp foam throughout. The actual rocket conversion took less than an hour. It
involves cutting a channel in the fuse for the motor just behind the wing
trailing edge, angled up at about 15-20 degrees, passing through the
airplane vertical cg. I made this cut using a sharpened ~29 mm aluminum
tube. You know you've got the thrust line through the cg when the airplane,
with tube imbedded in the foam, can balance on the end of the tube. Next
just insert a standard cardboard 29 mm motor mount in the channel you cut
and tape it in place with filament tape. The forward end of the tube needs
to be sealed off to hold the motor and facilitate ejection. Our motors are
held in the tube by friction and thrust. They eject 4 to 7 seconds after
burnout and just free fall. This gets rid of some weight for the glide home.
Most importantly, the plane must be balanced with the motor in place before
the launch. As we change motors in the field, I add or subtract weight as
required. The forward cg shift after motor ejection is inconsequential.
I have several mpg video clips of the launches, but no web site to post
them. I am willing to e-mail them offline to anyone interested. If anyone
has a web site I can post to, that would be better yet.
Ken Yunger
-----Original Message-----
From: Paul Klissner [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, April 18, 2001 1:24 AM
To: [EMAIL PROTECTED]
Subject: [RCSE] Model Rocket Engines on a Pico Jet
I saw a Pico Jet at Coyote today. That was a sharp-looking
little foamie. And (the part I love), it wasn't covered with
tape (I hate taping models, personal thing).
This was a neat teal color, of what looked like EPP or similar.
Anyway, it looks like it would be really fun to find a safe
way and environment in which to put a rocket engine in
and have a hoot (I'm talking about the little Estes
engines).
If one was to do this (again, putting safety first), where
would one attach the engines? What about thrust
vectoring, and the possibility of C.G. shift?
Is this absurd? I don't know, but for some reason
it just seems fun (to do in a safe way in a safe place).
-Paul
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