CR-10 Spool Holder for Enclosure

I design this thing for hold the spool inside my enclosure. I've got two different diameter of spool so I need a unique adapter. The spool holder supports spool with an internal diameter of 50 mm to 70 mm. I'm using the bracket included with the printer and this pieces:
-> M8 threaded bar 15cm
-> 3 M8 nuts
-> 2 608 bearings

Print all the things (two of spool holder 608), mount the 608 bearings in the spool holder parts, using the nuts to hold the M8 bar on the bar adapter and inse