I'm working on my F-86 and want to use "scale" control surface hinging. I'm using Robart hinges.

I've used the 1/64" ply method on the trailing edge and really didn't like it.

So, the other method I've seen is uses a concave cavity on the trailing edge of the wing and a convex surface on the leading edge of the aileron. How do you put the concave surface in the balsa of trailing edge of the wing with any accuracy over that long length?

Thanks