In this video I assemble a 12 speed Tamiya 70190 Mini Motor Multi-Ratio Gearbox which will become the drive motor for my radio controlled Liebherr A900C Litronic model. This range of speeds and torques should come in handy in the final set up of the model, particularly when trying to get enough torque for the dozer blade. The only issue is the gears are all plastic so they may break when subjected to stress of dozing gravel or sand.