Everybody has their favorite way to balance a planes, I have tried all kind of contraptions including ropes and pulleys, etc. but the method I described here makes sense to me and works because it simulates the actual flying position of the airplane. The CG machine makes you to balance the plane upside down which normally do not fly that way. I modified my Great planes CG machine by putting two add-on pencil eraser , the type with flat edge, at the end of the rods, then position the erasers at the CG points and lift the CG machine with a home made cam. This set up is more accurate and helps the guys who object using fingers.