Elastic Launched Glider C

[Jim_R]

Discussion for Elastic Launched Glider C

Elastic Launched Glider Wiki
2012 Trial Thread

Event Overview
How to Succeed in this Event
The Ascent & Transition
Incidence
Fixing Incidence
Circular Descent
Rubber Size
Roll, Pitch & Yaw
Flying Outside
Launch Method
Launch Videos

[chia]

Whoa, thanks for the nice list of forum links, that'll come in handy for sure!

I have a question already: what kinds of spaces will you use for flight trimming? Seems you need a gym, large hall, auditorium, etc., like for Wright Stuff, though Helicopter could technically be tested on an 8-foot ceiling. I'm having trouble finding a readily available testing place; school lunchroom/gyms/etc. are always in use, nearby elementary school's aren't big enough or open for use when I want it to be...

[retired1]

Soinc is a redheaded stepchild at my schools. Athletics of any kind are king! I wonder how it is in Solon, OH?
It will not be an event at our regional at this time, so the students will have to prepare for state with a 35' cluttered ceiling. It will take a lot of begging and whining to get the gym and then it will be at very inconvenient times. Everybody else with a high ceiling wants money!
We will probably do some testing outside in calm weather. Being in FL it is somewhat doable.
My church let me do choppers, but it is nowhere big enough for gliders.
Good luck.

[twototwenty]

Hmm, I was wondering about the same problem myself...as of now, I've jut been testing outside, which has yet to become problematic, but then again, I have yet to begin serious full launches of my glider. Hopefully I will be able to coerce my coach to get us access to my school's 2nd less-used gym.
At least for this event ceiling clutter isn't too much of an issue; you can just keep your launches at a safe height during testing.

[fozendog]

Retired1, same with our school. Athletics are highly favored as well. The problem I have found when launching is the air conditioning being a problem.

[retired1]

Very true if they will not let you turn up the thermostat a couple of degrees. It will put a premium on proper selection of the aim point as it could be disastrous at the point where climb goes to glide. Still, not as bad as it was for wright stuff or helicopters.

[fanjiatian]

I read the AMA website and online, but I haven't found much on this topic.

If the lift force is dependent on the area of the glider, density of air and velocity of the glider, what kind of an impact would two different shaped gliders with the same area have on the lift force and velocity?
Forgive me if my jargon is a bit messy, I'm new to flying events in general.

[_HenryHscioly_]

Different glider parts' shapes increase/decrease drag
With more drag, keeping everything else the same,
velocity will be less, so the lift force will be less and therefore result in a higher sink rate

Not sure what specific parts of the glider you are referring to, but other changes in the glider parts' shapes and positions, such as airfoil shape, incidence,tail moment, dihedral, will also affect the flight

[twototwenty]

Actually, the one factor you're missing is the friction of the glider in the air...different shapes will have different frictions. The page on the AMA website about freeflight trimming , which it seems life you found, talks a lot about this...just read it multiple times and take a little time to think about it, and it will give you a good basic understanding about how the glider flies in the air.

Edit:Looks like HeneryH beat me to it...What he and I said is correct.

[_HenryHscioly_]

Sweepback on the wing moves the center of lift further back..but if I wanted to do that, I could just move the entire wing further aft.
What are other purposes of a swept wing?
I read somewhere that a swept horizontal stabilizer will prevent flutter, what does that mean?