I thought up this idea of how to prevent or even eliminate flutter. Could you make an overhang on the wing that goes over the aileron so that the airflow goes right over the wing then right into to aileron instead of making a stop in the crease of the aileron and wing. Would it work or not?

But...............then the aileron would not have any deflection, or very little!

Hmm, one solution ive heard of to balance the surfaces.

Tom.

This is frequently done on full-scale airplanes. The control surface leading edge is a circular arc, with the hinge axis located at the center of the circle. Sheet metal strips extend from the wing, stab, or fin, almost touching the surface of the control surface. Cuts drag quite a bit.

I have used a simplified version quite often. I hinge the control surface near its upper surface, and angle its leading edge to fit into a Z-shaped gap in the wing or stab - something like a Frise aileron. Probably cuts drag by 75% or more, compared to the gross gaps often seen on models having thick control surfaces with lots of deflection.

Here's a photo of the bottom of the aileron on a King Air. There are trailing edge extensions which come out a few inches, (top and btm) and due to the pivot point of the aileron. (You could use Robart hinges.) there's plenty of control surface freedom.

If you use up-only spoilers you can have zero gaps (if you can build your wing true enough to not require "aileron trim".

Position them at 70% of chord or behind - max angle of deflection - you need at least 45 degrees of up - 60+ is better.

you can make them out of trailing edge stock - they should be 10%+ of chord in size.

Advantages:-

1. they do not require balancing

2. you can put a smaller servo on them: they are light

3. they work right up to the stall

4. you can have full span flaps as well as spoilers (if you need them)

5. They have no adverse yaw - only proverse yaw.

Disadvantages:-

1. For true axiality in say an aerobatics aircraft, you are better off with ailerons

2. If your plane needs aileron trim, you may be flying around with one spoiler up - which could be draggy I suppose.

3. You have to work out how to get them to be up-only. I have succeeded with mechanical mixing (extreme differential), and also with transmitter mixing.


I can't really see how to make the Z gapped aileron option you mention, Rotaryphile - can you draw a diagram and post? Would be very interested...

A lot of the sailplane guys use Gap tape. Its a stiff piece of tape with adhesive only on one half of it. The tape sticks to the wing and then covers the gap for the control surface. When the control surface moves, the tape just slides to allow for up andown deflection. All it really does is prevent the airflow from going between the wing and the control surface at the hinge point. This usually stops flutter.