This is derived from Surajmal's 'Internal Geneva Mechanism' posted on GrabCAD. Made in DiamondAge PLA on an Ultimaker 1. Makes a neat model but I've not seen one in real life. Suffers from the big disadvantage that the wheel in not locked in position during the dwell part of the cycle as is the case with conventional external genevas.Check the orientation of the parts before printing. For tall narrow parts suggest 0.2 mm layer and 220C. The fit of the indexing pawl in the geneva slots took quite a bit of filing etc. Once movable I found wetting with water make it easier to operate and soon it was nicely 'run in'.