The idea is to use a crossed belt with a mass and turns it like the first image. If Ω=0 all centrifugal forces cancel themselves. But if Ω is not equal at 0, the support receive a net force (red). This can be used for move the center of gravity without an external force. In one turn the red force cancel itself, but there is a delay and this delay can move the CG I think. I added a Pulley3 for have the mass than Pulley2, The Pulley3 don't turn, it's only for have the mass.