my new super-fast FFF flying wing - RC Groups
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Jul 31, 2003, 10:56 AM
Old school newb
PunkerTFC's Avatar

my new super-fast FFF flying wing


I make a little 24" span flying wing, for speed 280 power, and holy carp, this thing motors! full throttle level flight is probabally around 50 mph. And man, does it pick up speed in a dive! I built it just for speed, everything is internalized except for the battery and servo tops. Unfortunately, not internalizing hte battery was a BIG mistake. I was pulling out of a dive, and my battery decided to take a dive. From 300 feet. Onto my garage. Needless to say, my pack is destroyed (my only powerex pack for teh speed 280 on the plane!!), the plane is fine, and it was a very humerous incident, but now I need more batteries
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Jul 31, 2003, 11:24 AM
Registered User
ack got pics of the wing?
I would like to see the foil and thickness
Jul 31, 2003, 11:25 AM
Registered User
ack got pics of the wing?
I would like to see the foil and thickness

maybe the cutting jig too =)
I have been interested in making some wings myself
Jul 31, 2003, 12:42 PM
Old school newb
PunkerTFC's Avatar
no cutting jig involved, it's fan fold! Airfoil was fudged, i made the wing by making an AZ_Shrike wing, but then cutting at 30 degree angles away from the centerline of the wing to get two panels, then I cut the tips at 30 degrees, then I epoxied them to a center foam thing. chord at the root is 8 inches, chord at the tip is 4, and the wing tapers from 3/4 inch thickness at the root to about 1/2 at the tip (it's very very thin)
Jul 31, 2003, 12:45 PM
The original Flying Pigs Sqd.
Up&Away's Avatar
How can you post a thread like that, and not post pictures for us to drool over!
Jul 31, 2003, 12:53 PM
Registered User
Ha! I lost a battery just like that. Fell from about 100 feet and punctured it. Almost started a fire (it was an E-Tech 1200). What ever you do, do not let the 'juice' out of them cells. Looked like a smoke bomb went off.

So Punker, when are we going to see some pictures? Can you give us more specs? This sounds like a fun project!
Jul 31, 2003, 01:49 PM
Old school newb
PunkerTFC's Avatar
I'm gonna get the cam from my step mom today and take some pics of a bunch of stuff. Seriously though, this is a VERY nifty plane. VERY Fast, especially on a speed 280. The roll rate is also scary-fast. I estimate the battery hit the garage doing about 100 mph, which is 2200 joules of energy. About the same as a good gunshot . It dented my garage roof.
Jul 31, 2003, 02:19 PM
The original Flying Pigs Sqd.
Up&Away's Avatar
Enough already!

I have to put drool guards on my keyboard...
Jul 31, 2003, 04:46 PM
GenesisCreation's Avatar
I do believe it is against forum rules to make a post like this without pictures.

Looking forward to more info. Where is the c.g. and what prop and battery were you running. Thanks.
Jul 31, 2003, 04:53 PM
Registered User
2200 joules? u dropped a tesla coil? =P
Jul 31, 2003, 05:22 PM
Old school newb
PunkerTFC's Avatar
I took it flying again today, and my friend shot some pictures. It was going so fast on my 'slow' photo passes (*evil grin*) that he had a hard time getting it centered. I'll post the pics a bit later. My C.G. is 11.5 cm behind the L.E. at root (about halfway back on the root) although I think this is too far forward, because it's having trouble with inverted, and it shouldn't (it's a symmetrical airfoil after all!) the prop is a zagi prop (gunther 5.5x4.5 or whatever it is), and my battery WAS an 8 cell powerex NiMH pack (700 mah), but read my above posts for teh fate of that one ( I got a pic of that today too). Right now I'm using a 7x350 nicad pack, definitely not my preferred battery! I think the formula for joules is mass (in grams) x velocity (in m/s), correct me if I'm wrong, that's how I got my calculations. 55g x 40 m/s = 2200 joules.
Jul 31, 2003, 05:54 PM
Far Out Flyer
prof's Avatar

Joules


Joules is a unit of energy. Dimensions of kilograms x meters^2 / second^2. 1 J = 0.7376 ft-lb.

55g x 40 m/s = momentum.

A mass of .055kg at 100 mph (44.7 m/s) has an energy of 1/2 x m x v^2 = (.5)(.055)(44.7^2) = 54.9J
Jul 31, 2003, 05:57 PM
Old school newb
PunkerTFC's Avatar
heh, ok, you've put me in my place. Anyways, pictures are here!
Jul 31, 2003, 05:59 PM
Old school newb
PunkerTFC's Avatar
This is what happens when a powerex NiMH battery impacts your garage at 100 mph.
Jul 31, 2003, 06:02 PM
Old school newb
PunkerTFC's Avatar
here is the plane next to my TX, for a size comparison. It's definitely a small plane!


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