Re: Cat. 1 and & 2 glider weights (wings)?

From: doctorgonzo788 <doctorgonzo788_at_yahoo.com>
Date: Sat, 25 Feb 2006 17:05:59 -0000

> The Cat. 2 ceiling is 37'. It sounds like most of the numbers for
> weights I've seen on this list are for sites of slightly over Cat. 1
> max. Or, are you guys pushing the minimum weight and not reaching full
> height?


Hello Bruce

Just got home from flying at the Emory gym, actually. The ceiling is
35' clear. Air was on, so getting times is impossible. Bill and I were
there to see how our models launch in a bit higher ceiling. I was
flying my big HLG and my 1.4g standard. Both models had about .4g of
ballast added for the session. I was getting a 1.8g (total) Cat I
standard pretty close to the rafters. Flaps were buzzing, but I was
launching it on twice the rubber I use for Cat I. Bill was getting a
1.5ish gram standard to the roof without too much trouble.

There are other things besides weight that affect penetration. My
models always climb higher when they're new. As the leading edges and
tips get chewed up, everything suffers. The curvature of the bottom of
the wing, right up near the leading edge, is really critical for the
speed range. The leading edge curvature (sharp!) is another thing.
"Flappiness" of the flaps as well. Too stiff and they don't get up out
of the way. Too weak and they start buzzing. Neither of these is good
for the climb.

I always try to defy some law of the universe, by building
rediculously light, yet extremely strong gliders. I push the minimum
weight as far as I can, and then launch it as hard as I can. You can
get 1.4g of wood up 30' but you've gotta have a model that you can
really put some power on. Things start getting hairy though, as boom
flex and flap buzz threaten to make the model explode. If your boom
flexes too much, the stab might fold, and the model will tumble and
come apart in the air around your head. The flaps buzzing really
fatigues the flap wood, shortening the lifespan of the model and
screwing up the flex characteristics.

Seeing as how you've got so many wings and fuses, why not make them
interchangeable? Some combination has to work better than the rest.

Good luck, enough babbling from me.
 
Chris in Atlanta
Received on Sat Feb 25 2006 - 09:06:47 CET