Just mentioning - I used an ozito electric drill last night on some copper work for my brewery, and the bit got stuck, with the motor running but stalled. Within 2 seconds massive amounts of smoke came out of the unit and set the smoke alarm off. These cheap drills have no stall protection, so I would not leave this unit unattended on a mill incase you do stall it, based on the amount of smoke i saw, it will likely set on fire very quickly.