About three years ago I made this X axis power feed for my mill. The motor is from a small battery drill and when locked in low speed they have enormous torque, certainly enough for my Optimum BF20 mill. I locked the gear box with a hose clamp. The motors are easy to get at by dis-assembling the drill. For a clutch I just made a sliding brass dog which I flick in or out with my finger, it is very simple and has never given any trouble. Speed control is by a 10 amp DC speed controller from a local electronics shop, cost was around $A20. For the power supply I used one from a wrecked computer, they have a range of voltages and can generally supply 10 amps/ 12 volts. I made a case for it and included an ammeter. The motor draws around 6 amps at max load. Google offers plenty of advice on using these as a power supply. In the three years this has been in use it has never given a moments trouble, the power available from these motors through the planetary gears is astonishing. I might add that battery drill that it came from was of the cheaper brand. Cheers, Peter