You are right about how to operate the hanging type CG Machine. With the rope that the plane is hanging from looped around the dowel, you just rotate the dowel until the plane is level (checked with a bubble type level). You can get the plum bob to hang fairly steady in a short period of time. So the mechanics of operating the hanging CG Machine is easy. Establishing a hook to hang it from is normally not a problem in most work shops.

I don't sell these things so I am not trying to push them on anyone. I just think it is a safe, easy, accurate, and cheap method to find AND adjust the CG of a plane of any configuration. From what you wrote, Mr. Gravity will make the plum bob point to the correct CG no matter whether the plane is inverted, upright, single wing or bipe, 2 pounds or 40.

You answered my question about why it works with "Mr. Gravity". I guess there is really no need for any more details.
Thanks