Another Tinkeriffic Spool Bearing. I *know*, right? This one is designed to fit a **60mm** spool. I designed it to go with this spool of PLA http://amzn.to/1nPycNz , which appears to have a bore that's just wider than 60mm. There are a couple of STL's in the archive, one that's 60mm and one for the in-real-life spool I have. This three-part solution (thirteen parts, if one counts the 4.5mm BB's http://bit.ly/1ngex61 is designed to use a Tinkertoy rod as an axle and is a much, much smoother ride for your filament spools. I found inserting BB's into the original 608 bearing to be frustrating so I split the bearing in two and left it to the end user to super glue the parts together. The walls of the inner spool are by necessity quite thin; I recommend multiple shells or high infill for that part.