Simple holder for a bit of sponge to remove dust and hairs etc from filament before it goes through the feeder and extruder.
It may be a good idea to... lead your filament through a sponge to automatically clean off dust, hairs etc. Couldn't find one for my Ultimaker, so I made a very simple one with OpenSCAD. I think the sponge causes very little friction, so no issues with printing and retraction. I'll see how it goes, maybe change the design a bit.
Using the scad-file it's very easy to change dimensions if it doesn't fit your printer or if you want a different thickness etc. I made some stl-files with and without screw attachment and square cutouts.
cleaner.stl - simplest one, just clamp it on the filament feeder
cleaner_screw.stl - can be attached to the feeder using a screw that's already there
cleaner_squares_screw.stl and cleaner_squares.stl are the same with some squares cut out in sides and back to make it even lighter. More difficult to print though.
Cut a piece of sponge and feed the filament through.