Keep moving the CG back until the planes does not dive or climb during a 45 degree inverted upline. Fly straight, pull up to 45 degree climb and roll inverted. Plane should track striaght on previous path. If it dives, add more tail weight, trim and try again. I had mine flying real nice when the CG was 6mm behind the recommended CG.

If the tail drops and the plane stalls when you are landing then you may be too tail heavy. Make changes slowly so that you don't get yourself way out of wack.

"i have flown it and had to give a touch of neg trim to fly level," This is typically good. It should help the inverted flight and the knife edge.


Chuck is right, there is already a thread that is a few hundred comments long at the 3D section.