My newest addition to my homebrew line. I tried to justify buying an RCBS Trim-Mate but don't have an extra $100 sitting around. I got this idea from the Sinclair Intl catalog/website, but again, didn't want to drop $395 on that one either.
So I dissected an old Craftsman 7.2 volt drill whose batteries went dead years ago. Hooked it up to my homebrew bench power supply (old computer power supply) and found it turned at about the right speed with good torque. A little felt on the base makes it slide easy enough on the bench.
I can also use it independently like a Trim-Mate prep center by unchucking the trimmer.