Ender 3 V2 Filament Roller

This design needs 2 x 628 bearings which sit on an axle that recesses into the roller shaft. The internal diameter hole in the bearings are 8mm, so I made the axle diameter 7.8mm as it does not need to be tight. If using bearings with a smaller diameter hole, you could make a smaller diameter axle, and it will be ok. You cannot go bigger, however as the axle will not fit into the recess. The maximum width spool that this roller will fit is 90mm. I'm currently using 60mm wide spools, so I printed 2 x 10mm spacer washers that fit either side of the spool and keep it central. It works really nicely, I printed a separate washer that sits on top of the roller before it is fitted through and fastened with the nut. I did this to make it easier to print without supports. You will need to print all parts once, except for the 10mm spacers, which you will need 2 of if you plan to use them.