Have not tried it myself, but have heard of guys wh fitted a small dog arrangement on the end of a leadscrew and drove it with a cordless drill. A refinement to this could be to use the motor, gearing and control from old battery drills to make a permanently mounted setup. Sure it's been done before, and most workshops will yield one or two old 14.4v drills which work fine on 12v. A power source can be had from a battery charger or power pack for CB transceivers etc. Plenty of room for ingenuity. Regards, Combustor.