Hypocycloid reduction drives

I love the idea of hypocycloid reduction drives, or cycloidal reducers, because of they symmetry, their simplicity, and their promise of inexpensively using speed to get more power.

Some links I found about hypocycloids include http://www.thingiverse.com/thing:3617 and http://www.zincland.com/hypocycloid/

I’ve rediscovered – and written about – why cycloidal reducers aren’t commonly available.