I'd like to design flaps into my "scratch" built astro-piglet, using robart hinge points to get a pseudo-fowler-effect. What shape would you suggest for the wing-flap interface? I'm assuming I need a clean surface on the top of the wing, is the bottom also critical? The easiest thing would to just make it a flat junction, perpendicular to the plane of the building board when I assemble the wing. I was wondering if I should try an angled LE with the flap kind of "pointy" on top (such that when they mate in the closed position there is no break in continuity of upper or lower wing surface) so that the slot will be angled rather than just perpendicular to the wing when the flaps go down.

thanks,
Rick