Summary

A bearing with the same form factor as the 608 which uses 3mm-lengths of 2mm filament as rollers. A more refined version of my previous one, it actually has slightly MORE friction, but much better tolerances -- I'd estimate 0.5mm thrust and wobble. Careful sanding and cleaning might reduce that more.

Instructions

Your ability to make this work will depend on your ability to cut and manipulate dozens of tiny rollers out of ABS filament. Fill each of the holes on the jig with slightly more filament than needed then sand them flat. This is NOT a waste of time! Pointy rollers vs flat ones is the difference between a bearing that goes crunch vs one that goes whirr. If it goes clatter, you may not have put enough rollers in it, leaving a big gap inside.

Depending on the tolerances of your printer, the jig may be slightly too short or tall. Scale as appropriate.

Stick maybe 2 dozen on a piece of scotch tape, and curl it around the inside of the tall large piece. Insert the tall core, and add more rollers until it's full. Glue on the short large piece with ABS cement, carefully remove the tape with needlenose pliers, glue on the short center piece.

Weigh down the center piece with something while the glue sets. You want it relatively tight.

A drop of oil inside goes a long way.

Printable 608 Filament Bearing