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help whith simetrical wing

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Old 01-06-2003, 03:52 PM
  #1  
jimpies1935
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Default help whith simetrical wing

Hi

I need urgent help. I bought an advanced trainer, which look's almost exactly like most trainers but have a symmetrical wing. The problem is that the wing has no self-correction
And it turns extremely quick, I was wondering if I could build a wing with a flat bottom,
And just use it on my current plane or should I build an entirely new plane.

Thank
Jimmy.

Ps plans for a wing would be much appreciated .
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Old 01-06-2003, 04:58 PM
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banktoturn
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Default help whith simetrical wing

Jimmy,

I'm not sure what you mean when you say that the plane turns extremely quick. If the problem is that a very small motion of the stick gives you lots of roll very quickly, that is fairly easy to fix. If the plane has ailerons, reduce the throw ( the amount of aileron motion ), either by adjusting the linkage or by reprogramming your radio, if your radio has that feature. If your plane is rudder-only, then use one of those methods to reduce your rudder throw. As far as self-correction, that is affected by the dihedral angle of the wings. I can't tell from the picture how much dihedral the plane has. If you look at the plane from the front, the dihedral angle is the angle between the two wing halves. If you don't see enough self-correction, it is probably because the dihedral is insufficient. If you are comfortable building, then the wing can be cut apart and reassembled with a little more dihedral. The plane should have come with a range of recommended dihedral angles. This is usually described in terms of how high one wing tip will be from a flat surface if the other wing-half is held flat on the surface. It is also possible that you have the center of gravity too far back. The plane should have come with suggestions for this as well. Ideally, you should be flying at a club, with access to an instructor, or experienced club member, who can help you with these issues.

The symmetric airfoil of the wing does not have a significant effect on stability, regardless what some 'experts' might say or imply. I would not recommend rebuilding the wing to get a flat bottom, as there is no special advantage to it. Bear in mind that you are likely to get advice to switch to a flat-bottomed wing, as the effects of the flat bottom are commonly misunderstood, even among modelers with a lot of experience. As you gain more flying experience, the characteristics of a symmetric airfoil will actually be better for you.

Good luck,

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Old 01-06-2003, 08:37 PM
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MinnFlyer
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Default help whith simetrical wing

As well as cutting down the aileron throw, learn to fly with less than full throttle. You'll probably find that 1/2 throttle (or less) combined with a little up elevator trim will give you a much more forgiving airplane.
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