This is what it looks like. The vertical part is poplar 1 x 2 x 8 inches long. The dowel is 1" but a piece of a broom handle would work, about 14" to 18" long. The hole should be made to allow the dowel to slide easily through the vertical part. A slit is sawed from the hole to the bottom and a bolt hole cross drilled to allow adjusting the tension of the dowel. It needs to rotate but with some resistance. Theres a hook in the top to hang it from a little homemade block and tackle I made from hardware store pulleys so I can set it up on the bench then hoist it up easily. I use 550 paracord for the suspension harness but any nylon cord or even cotton sash cord will work fine. the suspension harness doesnt have to be any place specific, Ive moved it all the way to the tail and under the landing gear and it works the same. Make a plumb out of a sharpened bolt with a hole or find a small plumb at the iron mongers. I hang mine from the tension bolt so it is off just a tad but I can figure it out. Use at least three turns of cord around the dowel so it has a grip, you will rotate the dowel to raise or lower the nose/tail if the model and when you get it level (or a tad nose down) where the plumb is pointing is the CG. It's fool proof easy to make and accurate, balancing models with your finger tips is for trainers NOT SCALE AIRCRAFT. Build one you'll love it.