57 mm spool hub

Hub for 57 mm filament spools (I've had good experience from Excelvan filament, no affiliation otherwise).
Two versions supplied, both will do the job, but the B version makes for a more secure fit - use this if there are no side supports (other spools close by).
Insert a 608 ball bearing after printing and you are done.
Sketchup files supplied - reported to be manifold.