I'm building a Hirobo Cap 232/15 Nitro, The book says to balance the aircarft so the CG is 30-40mm from the leading edge, so far in building i have not used the manual. The placement of my equipment is based solely on my previous knowledge of building. I don't want to find out i have an airplane with a CG out of limits the first time i fly it. I hear the CAp is a very snappy airplane. How can i ensure my self that i have a forward CG, but not too far forward for the first few times i fly it. Anybody have any techniques or calculations to figure this. Is it necessary to buy a CG machine for balancing.