This is a test hypocycloid gear for aprox 64:-1 reduction on a NEMA 17 stepper motor.
The extra components needed for this are:
- NEMA 17 stepper motor
- Metric 608ZZ bearings
The output has 3x M3 holes with hex heads for coupling.
The planet gear may require a little sanding to make the bearings fit inside it, as will the offset shaft.
The slot in the offset shaft is for a tiny woodscrew or self tapping screw in case you need more friction against the stepper shaft. If the stepper has a flat section on it, make sure it's facing away from the bearings so the spacing isn't affected.
I have tested this design though not thoroughly. Also I've tweaked the design from the first print, still need to test changes.
Video of an earlier version working: http://youtu.be/D_uAb-iEb_Q
Updated to put parts centered and correct way up for printing.
Added a zip of the original Solidworks files (sorry, the naming doesn't match up)
Added zip of STL files and Parasolid - this set does not include the backlash required for extrusion printed parts.
Thanks to Alex Lait who wrote the python Hypocycloid cam generator: http://www.zincland.com/hypocycloid
(My copy is now horribly mutilated with metric and automatic naming)