Thanks for the reply Cafeenman. It's an 8' span B-2 bomber with an OS70x4 stroke on the nose. All up weight should be 9lbs. The control surfaces are scale to the real thing and are pretty big. The plan shows hinge location but I think I will put in an extra hinge on each surface. I don't know if the plan conforms to you're 3" rule but it sounds good. I definitely plan on pinning using tooth pics. Considering that I closed everything up how can I add another 1/4"of balsa? If I pin through the 1/16" top and bottom sheeting just inside of the 1/4" hinge surface do you think it will be ok?