Ender3 filament guide bearing

The Creality Ender 3 has an issue with filament chafe. With the filament lead coming down from above the machine there is a sharp corner at the extruder that chafes away at the filament. Designed to slide over the existing Z screw nut, the gentle curve of this large radius bearing is one solution to this well known problem.

The assembly is composed of two separate printed parts which snap together. Instead of printing the entire assembly at once, the snap-fit allows for the assembly to be printed without support material.

Here we can see the filament path from the spool mounted aloft, around the filament guide bearing and into the extruder.
Ender 3 continuing to print after ball bearings are inserted.

This design is a caged bearing. The bearings are simple steel balls salvaged from an old bicycle hub, and are to be inserted when the print is slightly over half finished, this allows clearance for the nozzle to prevent collision. A Gcode is applied in the slicer to pause at hight for the ball bearings to be inserted.

Gif illustrating the CAD assembly. Note the bearing cannot be disassembled without destruction after it has been printed.
MaterialPrimaCreator – PrimaVALUE – White PLA
Other Material18 Ball bearings – 4.8 mm
PrinterCreality Ender 3
Print onething:4653380