Here are some pictures of my 2 meter Pulsar Pro in the final stages of its build. I have a weight scale suspended from the overhead with a very small pulley attached. I run a cord through the pulley and tie it to the front and back of the fuselage just behind and ahead of the wing so the sailplane can move freely along the two axes. I then use a carpenter's plumb bob suspended from the center bottom of the overhead pulley. The suspended plumb bob always points to the current CG. I then suspend a small container, taped, to the nose of the plane and add the necessary bird shot until the plumb line points to the CG. When you take the plane to the field you have a very good starting point that you can work with, doing the dynamic CG location for your flight preferences.