Filament holder no rollers, slim

Overview

I was trying different holders to fit into my Heated Drybox but the best one I could find (it was this one, v2) still had issues. Namely after several hours of printing the  spool movement would loosen up some moving parts, then the spool made it's way between them, got pinched and as a result a printer jam.

After some trying out of various other solutions on printables I've decided to design my own. It got to hold the spool close to it's center - this way it could not get pinched. Plus it needs to be slim enough to fit 5-6 of those into the drybox. It got to hold spools from various vendors I have - they use different width and different internal spool diameter.

My first design used bearings. But it turned out they allowed the spool to rotate so well that after a slight pull from the printer it could do few rotations, that formed loose filament strands and they could form a knot and as a result printer would jam. You could actually see how this happens on one of the photos with 2 spools. The left one uses roller, the right one doesn't. The left one has some loose filament strand on it.

So I present here my second version without rollers here. It it slim enough, the hub doesn't move but that's a feature, the hub has some curvature to auto-center the spool during unwinding, the holder doesn't need any supports and the hub's supports are very easy to separate.

Printing

Since heated drybox temperature can get high, use PETG. If you don't use a heated drybox then PLA should be fine. I've used 0.4 nozzle and 0.2 layer height (structural). Hub 3mf file has some additional support drawn in, they are needed for robust print and are supper easy to separate.

Remixes

I designed it in Fusion, but not sure how to export it. It looks like step file should be as close to lossless export as possible, attaching it. It has two hub designs - without bearings and the one for standard roller bearings.