Sanding Disk holders

Added a third sanding disk holder, for 5 inch disks, total of six slots, with sets of three side-by-side. I have not printed this yet but thought others might find it useful.

two different sandpaper holders I designed for my son and myself. one holds 5" and the other holds 6" disks. the 5" design will fit on a Bambulabs X1C plate. the 6" needs to be cut. I test printed that one with a dovetail joint and it works fairly well.

Both designs have holes for screws for wall mounting