Low Friction Sideways Filament Roll Holder for Prusa I3

This project started when I got into printing flexible materials. Apart from reworking my extruder with this excellent design by Petehagoras, it also required a low friction, straight path feed of the filament into the extruder head. It had also always bothered me that the filament roll axis was perpendicular to the movement path of the extruder head. I found this spool holder design by HugoHuge, who was kind enough to provide STEP files of his design, and set about making my own version.

There are a few things to watch out for when orienting the spool this way: Clearance of the extruder head to the frame of the printer is critical, so there isn't much room to fix the spool holder arm to the frame. I had a snap in design that was working nicely, but it had clearance issues. So I switched to a pretty thin design around the frame, held in place by zip ties. The zip ties are the regular Prusa issue ones (2.5 mm width, 1 mm thickness).

I changed HugoHuge's design of the roll holder for easier printing. It still requires supports on one end.

To complete the build, you will need 2 608 bearings. You can get a 10 pack off Amazon pretty cheap, or if you have old skateboard wheels, these are pretty standard.

Print Settings

Printer Brand:

Prusa

Printer:

I3 MK3S

Rafts:

Yes

Supports:

Yes

Resolution:

0.2 mm

Infill:

20%

Filament: Prusament PETG black

Notes:

The roller itself needs to be printed upright and requires supports. I recommend adding a brim/perimeter in the slicer. Print together with the roll holder with setting "support on print bed only" that should suffice.
The arm should be printed lying on the side and need no supports. See screenshot from Slic3r for orientation.