This is a simple filament spool insert to allow a spool to spin on a M8 (or similarly sized) threaded rod. The legs are designed to bend a bit when inserted into the spool to allow for a snug fit. It was designed to fit into a spool with about a 75 mm diameter opening. Print two of these for each side of the spool. Only about 20 mm of the hole is touching the threaded rod which reduces friction and allows the spool to spin freely. SCALE UP BY A FACTOR OF 10 BEFORE PRINTING