Marble Exercising Machine - Part 3 - Motor and electrics

This part includes the motor assembly, battery holder clamp and blanking plate.

Parts needed:
One of each of the parts printed from the stl files in this part.
Five M6x15 cap screws (see part 1).
Four M8x7 medium thumbscrews (see part 1).
One M8x7 large thumbscrew (see part 1).
Two 8-tooth pinion gears (see part 1).
One 16-tooth spur gear (see part 1).

The following non-3d-printed parts:
The 12v 50rpm electric motor. This can be sourced on Ebay etc - search for "XD-37GB520 Brushed