This part can be used as a filament roller. Because it is so small, it can also be placed in a box.

I have additional information.

2 of the 4 rollers are 1/2mm shorter, these are the rollers on which the spool will later run. These two shorter rollers each receive two ball bearings.

These 4 ball bearings have the following dimensions:

• inner: 5mm
• outer: 14mm
• width: 5mm

These ball bearings are standard parts, feel free to use high-quality bearings to improve the running smoothness. Please do not use any adhesive on the ball bearings.

The two longer rollers are glued to the frame at the bottom and form the chassis.

To improve the grip of the spool on the rollers, I have shrunk heat-shrink tubing around the rollers. Now the spool rolls more smoothly, quietly and stably.

What do you think of it?