JollyPopper

My Feedback: (6)

I've read here on RCU a couple of times about a machine that you can hoist your airplane in and a plumb bob would point to the center of gravity. I could not visualize how the thing would work so I built one. And I still can't figure out what it is telling me. If I hoist a plane in the loops of this machine and then manually level the horizontal stabilizer using a carpenter's level, the plumb bob actually does point diredtly to the center of gravity. However, if I rotate the dowel around which the loops are wrapped, raising or lowering the nose of the plane, the pointer points at another spot. This seems to be telling me that the CG changes with the attitude of the plane. It moves back a little bit as the nose rises and vice versa. That doesn't seem right. The CG should remain constant regardless of the attitude of the plane, right? What did I do wrong? This thing looks like a really neat contraption if I can figure out how it works.