Hypocycloid gearbox for Nema 14/17

thingiverse

This 1:56 speed-reducing gearbox is designed for Nema 14 or Nema 17 stepper motors. It requires specific ball bearings including 2 x 10x15x4mm, 1 x 5x10x4mm, and 1 x 8x22x7 (608zz). The case measures approximately 40mm in length, so use at least 45mm long M3 screws. Assemble it with an M8 bolt, washer, and nut for the output shaft. The Nema 14 excenter can be press-fitted without glue or a set-screw. The gearbox aims to replace the large Nema 17 motor extruder mechanism on a printer, using a smaller Nema 14 motor instead. The M8 bolt output may be helpful for attaching a hobbed bolt or a larger feed wheel for better filament grip.