Hi, I’m designing a custom gearbox for the Pololu 20D 25:1 Metal Gearmotor, 6V (#3450).
I need the dimensions or CAD model of the small front motor shaft and the 10-tooth pinion gear directly attached to it.
I am not looking for the large 4 mm D-shaped gearbox output shaft or the rear encoder shaft.
The official STEP model only shows the complete assembled gearmotor, so I cannot isolate the bare motor/pinion geometry.
Specifically, I’m looking for:
- motor shaft diameter
- shaft protrusion from the motor
- 10T pinion outside diameter
- pinion width
- pinion position relative to the motor face
- module/pressure angle, if known
- preferably a STEP/CAD model
I want to reuse the original gears and build my own gearbox while keeping the 25:1 ratio.
If anyone has disassembled a 20D gearmotor and can provide measurements or a CAD model of the motor + pinion, I would really appreciate it. Thanks!
