A ring of tetrahedra that can be rotated in on itself through its center.Here is a short video (not mine) of a kaleidocycle in action: http://www.youtube.com/watch?v=4owFczeqqMQNOTE: Unless you have super awesome resolution on your printer, you will not be able to throw this file at it and get a working kaleidocycle. I'm putting this forward hoping someone might make a derivative with hinges a makerbot can handle.I initially tried to print one tetrahedra segment, but my printer's resolution is not fine enough for the hinges. So I put all six together hoping that the hinges, printed together, would support each other, but they welded together instead.As for the design, one of the six linked tetrahedra is different from the others as one of its hinges needed to be inverted to connect properly.