A filament guide with a retaining roller.

This filament guide has a main roller built around a standard 608 bearing, and a secondary retaining roller to prevent filament from jumping out of the guide. It also attaches to a standard 2020 rail with drop-in t-nuts, so it's compatible with all printers (or projects in general) with that type of construction.

Additional Materials

• 1x Standard 608 bearing (8mm ID, 22mm OD, 7mm thickness)
• 1x M5 screw, 10mm long
• 1x M5 drop-in t-nut
• 2x M3 screws, 16mm long
• 2x M3 nuts

Assembly

1. Print the "roller_body_right", "roller_body_left", "idler_strut", and "roller_shaft_collar" in black.
2. Print the "roller" and "idler" in an accent color.
3. Press the 608 bearing into the roller.
4. Press the roller_shaft_collar into the inner hole of the bearing.
5. Place the M5 screw through the left half of the roller body, then through the right half, and add the M5 t-nut and fix to your printer.
6. Slide the roller assembly between the sides of the body, and fix with an M3 screw/nut.
7. Slide the idler onto the idler strut.
8. Slide the idler assembly between the halves of the body, and fix into the slot with an M3 screw/nut.
9. Adjust the idler so it's at a suitable angle to allow filament to go easily onto the roller.

Usage

If you have a rack of filament (like I do), run your filament through this filament guide to prevent the filament from dragging on the frame of your printer!