The Libro-Struder is an original 3d printer extruder created at the Pueblo City-County Library District. It is part of the RepRap Libro project but is a general purpose filament extruder for all your filament-pushing needs. It uses plastic-on-plastic friction forces rather than toothed-gear biting forces to grip and advance a plastic filament. The Libro-Struder is less prone to jamming and slipping than the more common Wade or Bowden-type extruders. It can also be created with fewer specialized parts. The design explores the idea of using taken-apart pop rivets as tiny bushings on shafts. The current model does require a stepper motor that has an orbital gearbox attached. I have had much success with a Nema 17 stepper with a 27:1 gearbox, Part No. 17HS19-1684S-PG27.
Hackers encouraged to print their own gearbox. :-)
Original design by David Hartkop, Technology Trainer PCCLD.
Hardware:
Nema 17 motor, 27:1 gearbox #17HS19-1684S-PG27
4 x M3x8mm screws
Push-in pneumatic fitting for 4mm od nylon tube
18 gage steel…

An open source filament extruder mechanism for your RepRap 3-D printer. The design uses friction from printed parts to advance the filament, and is less pron...