Adjustable Printrbot Simple Metal spool holder

Modified the Printrbot laser cutting files to make this adjustable spool holder to put on the top of the Z-axis rods. In addition to fitting on the top of the Z-axis rods it also has expanded capability for larger spools that wouldn't fit on the stock spool holder from Printrbot.

The bearing holes are for the 8mm screws that come with the acrylic cut version sold by Printrbot. The tolerances were a little off so I made a second version but have not tested it with a print. Suggestions and i