3D printer filament spool holder-feeder

Assembly manual video: https://www.youtube.com/watch?v=AycjpLIU_gA

This spool holder can be screwed to a flat surface behind or next to a 3D printer and feed directly into the printer or via filament sensor.
It uses two rollers on 4 bearings(19mm OD, 6mm ID, 6mm tall) So that the filament can be fed from the spool with minimum resistance.
The only hardware needed is: 4 bearings per each spool slot you need, and about ~5-8 short wood self tapping screws per each slot depending on how firmly do you want to attach it to the surface.

! not shown in the assembly manual video !
the dovetail joints that keep the parts together are pretty loose so they require some minor glue up, i used CA glue, but hot glue / construction adhesive or plastic hot staples would work as well.

The native version is 3 spool holder, but there is also a 2 spool version and a single spool version
If you want more, you can use the "Custom spool count" back connector and front wall to bind together as many slots as you need.

All parts can be printed with standard filaments but be aware that if you plan to install this holder inside an enclosure, a regular PLA might soften and deform from heat. so PETG/ABS/ASA is reccomended

Do not print rollers out of TPU, it may sound like a logical choice, but soft rollers actually heavily increase the rolling resistance, according to my tests.

If i messed up the part alignment somewhere or some part doesn't slice properly, please let me know