July 4, 2017
Description
Yet another 608 bearing. 11 4.5mm (.177 caliber) BB's fit inside. After 5-6 BB's are added, align and use the little channels to force in the rest. I use the the butt of a screwdriver or large pliers to force them in part way then rotate the bearing to seat the BB in the raceway. Naming convention: raceway_offset-3.85mm_raceway-InnerRadius-2.3mm_OuterRadius-2.275mm
Relatively tight clearances but very free and smooth movement. I've used them in fidget spinners and my spool hubs.
Update: I tried printing 608_Bearing_BB_3.85_2.3_2.25 at .1 mm layer height but 25% of them came out too tight and I had to loosen them up with a high speed drill so I replaced it with 608_Bearing_BB_3.85_2.275_2.275 and printed at .15 mm layer height with .25 mm and .40 nozzles. Also, inspect the raceways for defects or extra filament.
Added another bearing with slightly looser tolerances: 608_Bearing_BB_3.90_2.3_2.25 and the various iteration parts so you can mix and match so long as the raceway offset is the same.
License:
Creative Commons - Attribution - Non-Commercial - Share Alike