RCU Forums - Wing rock

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- - Wing rock (https://www.rcuniverse.com/forum/3d-flying-82/626602-wing-rock.html)

What exactly causes it? I don't want to know cures, but I would really like to know what causes it. Why do some rock upright, but not inverted?

Thanks! :)

Good questions! I have found that my lighter planes (wing loading / cubic loading) are much more steady in elevators and harriers than the contrary. As much elevator throw as possible is a must also. Interested to hear what others have to say_bob

yup.. with low elevator throw you migth aswell give up. with an unstable model 45degrees is minimum.

high wing loading and tapered wings tends to cause it.

What you guys are saying really doesn't stand to reason. At least, that's the way I see it.

My profile has a really thick wing. It is constant chord, so there is NO taper. The wing loading is very low and I have AT LEAST 45 degres of throw both ways. What gives? It does not matter how high the nose it, it wants to dip a wing. Then she dips the other wing...

If what you guys are saying IS correct, it does not explain why some airplanes will do it inverted, but not upright.

Thanks for the replies. More are welcome! :)

I would really like to get this figured out...

I think he means tapered leading edges.?.?

Quote:

Originally posted by BotleRocketWar
What you guys are saying really doesn't stand to reason. At least, that's the way I see it.

My profile has a really thick wing. It is constant chord, so there is NO taper. The wing loading is very low and I have AT LEAST 45 degres of throw both ways. What gives? It does not matter how high the nose it, it wants to dip a wing. Then she dips the other wing...

If what you guys are saying IS correct, it does not explain why some airplanes will do it inverted, but not upright.

Thanks for the replies. More are welcome! :)

I would really like to get this figured out...

I think when he is talking about low wing loading he is talking about extra's and edge's etc. around 28-30 oz/sq. ft. is good.

Your profile is going to be around 12-14 oz./sq ft. Just depends on your plane. Add some spoilerons (reversed flaps) about 10-20 degrees and that should make your extreamly light plane loose some of that unecessary lift from the wing and keep it from rocking.

Depends on your plane. The Fazer needs spoilerons to do it and the sledge doesn't need anything.

My thinking was in fact for larger sized planes. As a rule of thumb, the larger the plane, the easier they are to elevator and harrier. I do have two Morris profiles that will hover all day long, are light etc, but won't elevator or harrier at all. That is, a true elevator. Never had any luck with profiles or my Aeroworks Freedom 3D in an upright elevator. Can't explain why it did a sort of inverted on though :confused: