KD310 polishing helper

Use a m3 spacer and fasten the steelball or the magnet with it in your in your drill.
Polish the parts with a sheet of fabric and a polishing agent utilizing the drill. I've used Autosol metal polish.
The ball is 9.25mm and the holes are 10.5mm and 10.25mm. Depending on the thickness of your sheet you may need to change dimensions (fusion file included).