Stick Jammer: I hear what your'e saying, however, after constructing two other GSP models and having no prior warning per instructions, I had no reason to suspect that the underlying substructure was inadequate. I think that my problen in detecting anything wrong has to do with my using a power screw driver. GSP clearly intended to have the servo screws attach to the balsa, and though the balsa was of good quality and hard it was not an adequate support. Had I realized this earlier, I surely would have added support.