better way to balance a plane from side to side. fishing line. with the engine, radio, and all hardware mounted tie the fishing line around shaft on your engine. Pull out enough line to have it about 2-3 feet above your plane, and then tie the other end around the tail as close to the rear of the plane as possible (you can put some foam or paper towels under the line to keep it from cutting into the wood). then just simply lift the plane from the approximate middle of the line. you'll get an immediate answer to the side to side balance. or if you need to leave it suspended while you balance it. you can use more fishing line and suspend it from the ceiling.

hope this helps