Ender 3 universal spool holder

This is a redesign of https://www.thingiverse.com/thing:2999446/ by Jaypirnts.

After converting my Ender 3 to direct drive, I had some printing artifacts due to filament tension when using single-arm spool holders, which support the spool through the center hole. This design resolved all my issues. The spool is supported from the bottom and moves easily with very little force needed for unwinding (hence, no artifacts due to filament tension).

I like the idea very much, but the original spool rails are very unstable, and spool could fall easily, for example, if you need to move your printer. This is a complete rework of spool rails. The design is much more stable. I include original 20x20 profile supports and ball-bearing bushing.

You will need:
4 x 608zz bearing (or you can use https://www.thingiverse.com/thing:3295083)
4 x 15mm M3 bolts and nuts (can be longer)

This design works with any 20x20 extrusion profile.
The maximum spool width (outer size) is up to 93mm (the