RE: CMPro Lancair
Hot Rod Todd,
You speak truth, kemosabe. I ran the numbers tonight, and 72mm corresponds with a 30%MAC balance point, which is about where you would want it in most cases. In addition, the Lancair has a symmetrical airfoil, with no pitch moment, so you might want the CG even a bit forward of that, assuming a zero-zero decalage setting. Your 67mm is making more and more sense to me.
I installed my battery pack back behind the trailing edge of the wing, on the fuselage floor, and my CG is right at 72mm now. I think I'll try that, and see how it goes. Should be close enough for starters, anyway. It still sits pretty solid on the nosewheel, so the mains are plenty rearward on this model. I'm betting you really have to rotate to get it to unstick on the take-off.
Don.