A little bit of nostalgia to dress up your printer and provide some visual feedback. This model is based on the old plastic 45 record adapters that were used to make the 45 record holes fit the smaller spindle. Simple to print in standard PLA. No supports needed. You can print this using the standard .2 mm Standard profile from just about any printer. The magnet I used was 8mm height x 2.6mm diameter. The magnet is just small enough to have a very small amount of play so it doesn't rub the motor case. A small drop of Super Glue or CA Glue works well.