Thought I better add something about this plane and flutter.

Apparently the shape, size, weight, and location of the elevator in the Sportster series of planes is conducive to flutter. Your horizontal stab and elevator assembly may seem secure, but if flutter occurs, something is going to give. It would be a really good idea to look into the "fixes" that I believe Great Planes published for the other Sportsters. Fixes for problems like this generally include sealing the hinge gap, setting up the ideal control linkage hookup, and in some cases mass counterbalancing the control surface. You might also add simple cable bracing to the horizontal stab and vertical fin, or some streamlined aluminum tubing below the horizontal stab to the fuselage as bracing.

AV8TOR