Wankel Rotary Engine

This remix
* combines the main rotor with the larger tooth outer gear (no more gluing)
* increases the size of the mounting holes for the back-plate (less likely to snap)
* replaces the round handle fitment to the engine shaft with a hexagonal one (no more slipping)
* adds an adapter for connecting a power drill to the model in place of the handle

The model should not require any gluing, unless you feel the press fit is not enough. I have made the handle to shaft fitment slightly loose so the handle can be removed for easy disassembly.