Bearing Spool Holder

This is a filament spool holder where the spool rests on the bearings for a low-friction spin. For at least one of my spools it's too little friction, so I spin it around so the spool rests on the plastic and not the bearings.

It's inspired by a couple of recent finds, but those didn't have the mounting that I needed, and I already have an M8 rod mounted so I can use that for strength and for holding the bearings.

It can be customized; the STL as published will fit spools up to 70mm wide with holes 32mm or larger.

Be aware that some spools don't have their holes the same size all the way through; these might rest crookedly if one edge is on the plastic and the other on a roller. Turn the mount over so it sits straight, but adds friction.

I've added the mount that I had designed; it uses the large nut that originally comes with the printer (my Ender 3 and i3 clone both use the 32mm nut/thread)

Apart from three or four 608ZZ bearings, you will need an M8 rod to act as a bearing spindle and so you can attach it to your mount. You will also need an M8 nut to hold the rod to the mount; I used a nylex lock-nut but a pair of ordinary nuts will do.

The quick-release nut I use that stops it sliding off is https://www.thingiverse.com/thing:2675509. Tighten it a little if you're not using the bearings, so it doesn't rotate back to them. (edit: Also pictured is https://www.thingiverse.com/thing:2387197)

V3 (2019-01-11) Some of my newer spools have a rolling edge only the first 10mm from the outside, so I've moved the first and last rollers closer to the edge.

[2018-07-21] Bonus. It fits my new Ender 3, so I've added that as a tag. Added mount and parts list.

V2 (2018-06-05) I've added a fourth bearing; three left too large a gap for some of my narrow spools. The two-tone result is because I ran out of blue two thirds of the way in.