Goldguy Is Right: Round Flies Better

It's a Nutball without the polyhedral. It's a round Pizza Box Flyer. It's the USAF UFO.

I'm a big fan of the Pizza Box Flyer, but I'm not a fan of the pitch sensitivity. I wondered what it would be like to fly a round one, and I recalled that on the All Things Round thread I'd seen something called the USAF UFO, by the always excellent GPW. Pardshaw built one and loved it. I built mine along his recommendations:

24 inch diameter

1300 kv Blue Wonder

500 Mah battery

He recommended huge elevons, but what does he know? I scaled mine up from the 21 inch plan provided by GPW. I'd show him.

It flew really sweet. It climbs at half throttle. It has a very low wing loading so it's very floaty, but with the throttle up it gets fun. Which was the problem. The roll rate with those little elevons was slow, too slow to get out of hairy situations before smacking grass, and the whole reason you build something like this is to get into and out of hairy situations.

I cut the old elevons out and installed bigger ones. I measured 6 inches up from the rear, drew a line straight across (leaving a 2 inch strip for the tail) and cut new surfaces to fit. The throws are maybe 35 degrees and I've dialed in 40% expo. And the result? Amazing.

It has all the benefits of the PBF without the pitch sensitivity. It's smooth, in a dive or a climb, but it still loops in almost it's own length. It's just as wild as a PBF but it's easier to fly. I love it. Don't think I'm going back.

Pardshaw raves about it, and I think I recall Goldguy saying that "next to a UFO, the PBF" provides the most fun-per-buck. I think I agree.

That huge tail is odd looking but MAN does it keep this thing straight, even in wind. I bet the Pi Yak is a hoot (it's this thing with a fuselage and a functioning rudder). 

The only problem is that when you see it in profile all you see is tail. The wing turns invisible. It's a little disconcerting if you're far away.

Very pleased. It's my new favorite.

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PS: The fuse and tail are all one piece and L-shaped. The fuse on mine is 1.75 inches tall. The tail is 9 inches tall and 4 inches wide. The whole thing is 12 inches long. 

PPS: Built it out of Model Plane Foam, which I love.