ORIGINAL: Flyboy1958
Thanks, it would be neet to mount a servo in the fuselage, put a long arm on the servo and attach a weight to it. Balance the airplane, then with the servo on a spare channel and assigned to a knob, just move the knob which would reposition the weight fore or aft moving the CG. Once the airplane has the right feel, check to see where the balance point is and remove the servo and weight. Then reposition the battery and such to balance in the same spot. I know, it sounds like a radical idea. It's just something I have always thought about trying.
i saw a guy on rcu about 2 months ago who had made a balsa wood sleeve that his battery slipped into and it was on a balsa track (all homemade) and he did exactly what you are talking about, except with his battery! i tried hard to think of a use for that and i guess 3d flight would be the only reason i could think of that you might need your cg to be adjustable like that all the time, unless your battery needed to be back in the fuse where you can't reach and so you use a servo to place it? but it looked really neat, as he had spent a lot of time on it obviously!