parametric gearbox module v2

There is a newer version in https://www.thingiverse.com/thing:2392281

Parametric gearbox module used to construct gearboxes in toys.
Gears with simple support to be cut off.
Example of two stage gearbox build using the module.
Small gear to be driven by motor with 2mm axis.
Output set on hexagonal 4mm shaft.
Everything customizable in .scad
Engine mount module for standard DC 6V motor with 2mm shaft.