Aug

If you had to make a backing plate for this control horn that will be for the ailerons on a 20cc size plane, what would you use for the material?

jester_s1

Are you talking about something to go on the outside of the covering on the other side of the horn or something to replace the balsa wood in the surface itself?

jetmech05

I wouldn't...the plastic horn with the plastic backplate the screws bite into the back plate. The horn you have uses wood screws and glue to bite into the wood of the control surface. A drop of glue on the screw will be good

Aug

Yes it will go over the covering material. I thought of plywood but too much work. How about cutting it out of an credit card type material? How about cutting it out of an old CD?

JohnBuckner

My Feedback: (1)

I would go ahead and use it with a back plate. I of course have used the type that is glued & srewed but just never felt comfortable with them and have experienced failure with both but the difference is I have never experienced the backplate type completely separating but have the glued & screwd.

My first choice would be .050 or less aluminimm but realize you likely don't want to use that so my next choice would be 3/32 birch ply. The reason why I don't like the plastic cc card is it is not as thick a normal control horn back plate and a more brittle plastic material. Remember you may experience more vibration with this 20cc gasser over the glow or electric stuff.

John

Aug

Got it. Thanks. I'll stick with the plywood.

A. J. Clark

I had the same situation with a nylon horn where they supplied wood screws.
I used a strip of brass on the back side with #2x56 screws run from one side
through to the other. The nuts were on the bottom where they couldn't be seen.

Aug

Thanks. I didn't think of using a nice thin sheet of brass.