Replicator (dual) step-struder flex filament feeder

When browsing for some filament, found the 1.75mm FPE Naturel Filament Shore 40D

Could not resist getting a roll and trying some things out.

My replicator however did not want to feed the stuff through, so needed a simple modification for my printer.

What do you need:
- 2 ball bearings (ID 4mm OD 8mm)
- 4 mm screw