Tippe top

Tippe top, also called inverting top or flip top. Known to have amused nuclear physicists, namely Niels Bohr and Wolfgang Pauli. For more details, check the top's Wikipedia page: http://en.wikipedia.org/wiki/Tippe_top.

Getting the top to invert was a little tricky. I couldn't find the right proportions for the top online, so I tweaked the parameters in the openscad script until the top started working. It can probably be improved, tippyness-wise.