This one prints up without supports and the mounting magnet is optional. The plastic cutter works ok, but making one out of brass or aluminum would be better.
The magnet cutout is for a 12mm round magnet of any depth from 2-12mm. I used a 3mm deep x 12mm round, glued in after printing.
ProTip: Paint a swatch of slow-setting super glue on the round part of the cutter where the tape meets it to provide a better surface area for the tape to stick to. Scotch tape does not stick to PLA very well, but it will stick very well to the cured super glue.
maker geeks, inland htpla
mixed batch, black