I made a slo-motion video of a Hoberman Flip-Out wobbling between blue-in and blue-out states: https://m.youtube.com/watch?v=VC_KKTGWIOY Has anyone tried to analyze this phenomenon? Qualitatively it seems clear what's going on: centrifugal force (or whatever we're supposed to call it since it's not "really" a force) causes the thingies to spin out, and they overshoot, so then centrifugal force spins them the other way, and so on. But that's only a crude sketch of the dynamics. The Flip-Out has only one configurational degree of freedom, so it might be possible to solve it analytically and figure out the period of the oscillation (as a function of the position of the axis and the angular velocity), at least if it's rotating about some axis of symmetry. Jim Propp