Still looking for a cheap-ass polisher for safe-and-easy knot-cup-brush use? Here’s one similar to the one I have, and it’s $30 right now at Harbor Freight. As I’ve said before, I like these for knot-cup brush use because they spin slow enough to keep the wire in the brush — and out of your belly/arms/etc.
This one features a cheap-plastic housing, a motor of unknown manufacturing and durability — though I’ve been using mine for four or five years now — and a 300-3000 rpm variable speed setting.
It also ships with a 7″ hook-and-loop backing pad, but you can pitch that.
7″ Variable Speed Polisher/Sander [Harbor Freight]