Magnetic Rack for 8, 1.5mL Tubes

thingiverse

This magnetic rack accommodates eight 1.5mL tubes, with each tube held securely by small arm holders, even when turned upside down. The cost is mainly due to the magnets, which are approximately 70 cents apiece. For optimal performance, use these recommended magnets from KjMagnetics and apply epoxy for a strong bond. To attach the magnets, start with an outer magnet, position a tube inside as a guide, then glue the next magnet in place followed by the second one. Repeat this process until all magnets are secured. The design minimizes plastic usage and warping during printing; however, printing a raft is advised for smoother operation. An updated model features a roomier base and tube grabbers without overhangs, as suggested by comments. For graduate students trying to convince their PIs of the benefits of 3D printers, creating a few of these racks can demonstrate its value.