I have a U-Can -Do 46 that has needs Aileron differential in order to fly straight, the wing looks straight from the naked eye, the other thing about this wing is, it is hard to tell where center is because of the wing shape, should I try to recenter the ailerons in diffferent position and see what happens? I am out of ideas, it flies ok with the differential but not to good when I start doing manuvers.....thanks in advance.


Mike Hoffman

Mike :
What does it do, or not do during maneuvers. might be able to help there. If I remember ,Ucando has a full symetrical wing, so differential should have no, or little affect on it, unless it is changeing something else that is out of wack.

I’m assuming that by differential you mean that one aileron is trimmed up and the other is down to maintain level flight. A couple things I’d check are as follows:
-check the lateral balance (hang the plane by the spinner and tail wheel and make sure it hangs level. Add wingtip weight as necessary)
-make sure your elevator halves are aligned.
-try to borrow an incidence meter to make sure the wing isn’t warped. If it is seriously warped, you might be able to bug great planes into sending you a new wing

Tom

Thanks for the great replies, Tommy what happens is when I give it full down to tumble or full up to tumble it does like a corkscrew type manuver, or when I try to hover it fall off into a corkscrew thing, I checked the lateral balance and it is dead nuts, you dont think the differential would cause that?? Any help is appreciated thanks to both you guys .....really.


Best Regards,
Mike.

Sounds like a wing warp, as Tom says, causing one wing to stall before the other. If you don't have an incidence gauge, stick pins in the centre of the leading edge and trailing edge, at the root of both wings. Do the same at both tips. Prop up the tail till the root fore and aft pins measure the same height from the table. Now do the same measurement at the tips. The fore and aft pins at the tips should be the same height from the table. A little washout wouldn't hurt, but wash in is a no no. Hopo this helps. Can be done without the fuse. if you prop the wing up level on the table.

Sounds like there might be flex between the elevator halves too. How are the 2 elevators driven?

The elevators each have their own servo with a y reverse they are moving the same distance as far as I can tell, a funny thing happened yesterday, a new wing showed up from Great Planes, I never asked for it, maybe I'll build a new wing and see what happens. The wing shape is hard to see where to center the aileron also there is no no real line to follow so how should I set them up???

I bet what happened was that GP realized that one of their wing jigs was warped, and so they sent new wings to people who got models from that jig as a pre-emptive, keep-customer-satisfaction move.

As for setting up the ailerons, just eyeball them as best you can, and you should be fine. THe key is to try and get each wing half to be as close to mirror images of each other as you can. This way the two wings should produce the same lift right up to stall, and they should stall at the same time. Turn your radio on, center your ailerons, and look at each wing tip. The ailerons should be an extension of the an imaginary line drawn from the leading edge to the center of the wing hinge line. Then look at the center section of the wing from behind the wing. The inboard trailing edge corner of each aileron should line up with each other.

While you're at it, do the same for the elevator halves. Make sure everythings lined up nicely.

And you *SHOULD* be fine...
...famous last words... I know

Tom