Don't print one yet! The friction is too high. I'm working on fixing this.
This is a remix of the LibroStruder, but done in OpenSCAD, so it can be easily changed.
I've remodelled it for 3mm filament, and using Greg's Wade Reload gears for the NEMA to drive bolt gearing. I've added them here for ease of finding :)
It uses two grub-screw modded M8 nuts to couple from the drive bolt to the drive gear.
Partially threaded M3 bolts instead of rivets
3mm/4mm brass tube bushes
Needs some kind of mount