The front balance point was already determined (there was only one place to mount the front bolt), but where should I drill the 3/8" hole for the aft pivot/balance point? That was determined fairly easily by putting the front bolt on a stand (actually, I used a jack-stand from a car) and then putting the rear 4"x4" flat (horizontal) on a small pipe that could be rotated either in or out (ie: towards the top of the fuselage or towards the bottom of the fuselage) until the 4"x4" floated on the pipe; that's the balance point.
Once I had this point determined, I needed a way to keep the fuselage locked into a rotated position. For that, I mounted a plywood disk on the 4"x4" post at the balance point. The 3/8" bolt will go through both the center of the disk and the 4"x4" post.
Laying the fuselage on its side in preperation for finding the aft balance point.
Note the line drawn on the 4"x4" post and marked CG...that's the balance point.
