Well here goes... Aluminium frame router design

[Neale]

Quick answer to your question about "2 volt motors". Ignore motor voltage ratings. For all practical purposes, they are irrelevant. The control electronics are driving short pulses through the motor windings and include some clever controls on motor current, which is the important bit. The motors work using magnetic fields; the higher the current the stronger the field and the more torque you get out of the motor. However, the motor windings are coils of wire which have inductance. In this situation inductance is a bad thing because it slows down the rate of increase in current at the start of each pulse so you lose power. To get round this, you drive the coils with many times their rated voltage - maybe 60-70V for a nominal 2-3V motor - so the current builds more quickly. Then the current limiter in the driver reduces the applied voltage automatically during the pulse so the motor isn't over-driven. This all happens like magic and all you need to know about is the current limit setting in the driver module which should match the motor.