ORIGINAL: edsplane
You will find a good discussion on CG location at
www.rcaeronauts.com.
You should know that the CG must be located forward of the Neutral Point. The farther forward of the NP, the more stable the plane, but the less aerobatic. So, you must also find out where the neutral point is, as well as the CG. The information at the rcaeronauts website should give you an idea of what to do.
Good luck.
Ouch..........
So the CG information at rcaeronauts is in the form of a $28.95 application.
That's pretty steep for something that is available for free all over the internet. For example, the application at
http://www.geistware.com/rcmodeling/cg_super_calc.htm is free. It figures the NP, which is what every valid CG application would do, while computing all the needed areas and moments for you. All you do is plug in the necessary measurements. The measuring only takes minutes to do.