The Mini Mill is a fun little weekend project, and can be used to light a LED, small light bulb, or even charge a couple of NiCad batteries.

Parts Required

Stepper motor from old FDD or Printer. The square type is easier to mount. 25mm PVC pipe, about 200mm long 90mm PVC pipe, about 350mm long 4 of 3mm diameter 30mm screws 200 * 150mm piece of 3mm ply wood Stainless Steel hose clamp to suit stepper motor diameter + 10mm Double AA battery holder and lead Veroboard 2 full wave bridge rectifiers 47uF 63volt capacitor 10ohm 5 watt resistor hookup wire
First up remove the stepper motor from the old FDD or printer. The square type, as shown here, are preferred for this project as they are easier to mount.
Next you will need to remove the aluminium wheel from the stepper motor shaft. Easiest way I've found is to mount the stepper motor in a vice with the wheel up, then quickly heat the wheel with a small gas flame ( blow torch ) while prising upward with a couple of screw drivers or long nose pliers.
As soon as the wheel is free spray the stepper motor with water to cool it off. Excessive heat in the stepper motor will damage the magnets.

Next - Putting it all together