Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4862712.

This is a filament feed pulley system for the Voxelab Aquila 3D printer. The brass feed hole in the extruder will become worn from the filament without something like this. There are other designs out there, but they all require a ball bearing. My feeling is this is overkill. My design uses no bearing and all you need is your printer to create it. The tolerances are very sloppy and the pulley moves freely. Wear is not a problem as the movement is very slow. The bracket mounts in the existing holes on the extruder bracket with two M3 screws.