RE: building 4* 40 wing questions...
hi, before you glue the root (center) ribs, put the wing halves on a flat surface. now take your dihedral tool and that is used to set the angle of the root rib on each wing half. once you have the root rib angle set with the dihedral tool, CA the root rib in place. Make sure the top of the root rib is leaning toward the outside of the wing panel. now after the glue dries butt the two wing panels together. Before you glue the panels together trial fit them to make sure they fit proporly and check the dihedral brace as well.
Hope this helps!!
Jon