Assembled extruder.jpg
Project data
Authors Nick Dubiel
Completed 2014
Made? Yes
Replicated? No
Export to Open Know How Manifest
Page data
Type Project
Keywords extruder, filament, plastic, recycle, metal, motor, wire
SDGs Sustainable Development Goals SDG09 Industry innovation and infrastructure
SDG12 Responsible consumption and production
Authors Nick Dubiel
Kathy Nativi
Published 2014
License CC BY-SA 3.0
Affiliations MTU
Michigan_Tech's_Open_Sustainability_Technology_Lab
Language English (en)
Page views 1,772


Filament is expensive. Recycled plastic is cheap. This extruder allows you to create cheap filament from ground/pelletized plastic. Important!!!! You will need metal working tools to make this properly, a lathe and mill are highly recommended but it is possible to get a way with an angle grinder and drill press. This is a very early prototype. It functions but is not ready for the mass market more work is needed.

Bill of Materials[edit | edit source]

The STL file for the part and openSCAD file can be found here:

File:Coupler.stl

File:Bearing block.stl

Tools needed for fabrication of the extruder[edit | edit source]

  1. Lathe
  2. Mill
  3. Drill Press
  4. Files
  5. Wrenches
  6. Allen Wrenches
  7. Screwdrivers

Skills and knowledge needed[edit | edit source]

  • Machining
  • Basic circuity
  • Basic knowledge of plastic Extrusion

Technical Specifications and Assembly Instructions[edit | edit source]

  • Grind/mill 2 inch slot into 1/2 npt x 6 inch pipe so that plastic pellets can enter the feed screw.
  • Drill 1.25mm hole into center of brass cap to make nozzle.
  • Need to remove paint from ship auger bit use oxy/acetylene torch and hit with a burst of oxygen while moving along the bit. using the motor to turn the bit is very effective. Do not get bit too hot or it will warp!!
  • Machine remaining metal parts to prints provided.
  • Wrap 2 layers of Kapton tape around the barrel end closest to the nozzle. Then wrap nichrome around barrel making a 2 inch long coil without letting the individual coils touch, can be done in one layer no more than 2. Wrap coil in a second layer of Kapton to keep coil in place. total resistance should be more than 120 ohms more is okay less means you need to redo the coil or risk fire hazard.
  • Assemble similar to filastruder instructions.

Common Problems and Solutions[edit | edit source]

PLA has low melt strength and makes a small coil when extruding. Filament winder is needed. When changing filaments material is caught between two sections of pipe in floor flange necessitating removal of barrel to remove previous plastic. Crystalline plastics(PET,PE,PP,etc) can cause catastrophic failure. Extrude at own risk! Do not extrude indoors!

Cost savings[edit | edit source]

Abs is available for $3.00 a Kg compared to $20.00 for mystery ABS. PLA is available for $4.50 a Kg compared to $22.00 poor tolerance filament. Polycarbonate is available for $20.00 Kg compared to $75.00.