Thanks, Bruce! I already glued in dihedral in my wing, but your changes could allow some one else to make a flat one. I like the idea of outward-angled tip ribs (plates, whatever).

I drew it in Deltacad (.dc extension). It exports to .dxf ok except line weights don't get preserved very well. Splines, text and circles seem to export fine, though.

I'll PM you for your email address and send you both versions.