Sector67 interns, Mitch and Kyle, already have their main summer project in working condition. Their new filament extruder is able to take plastic pellets, and convert them into plastic that can be fed into Sector67’s 3D printers. The main motivation for the extruder (other than awesomeness!) is that extruding plastic pellets costs about a third of what filament does. “Cheap ABS pellets can be put in, and a more valuable product comes out,” says Mitch.
Kyle (left) and Mitch (right) in front of their filament extruder
Not only the does the extruder work, but the interns have already successfully used their filament to print plastic parts on Sector67’s 3D printers. And as long as Sector67 doesn’t try to fund the next addition by selling filament, Mitch and Kyle’s extruder should have plenty of throughput. “This extruder will be able to extrude 5-7 pounds of plastic per day—far more than we use in the printers”, says Jim, a long-time Sector67 member and 3D printing entrepreneur. Jim is also responsible for building the hopper using his patent-pending interlocking container design.
How it works
1) ABS pellets are fed into the hopper. The hopper was made by Jim using his patent-pending interlocking container design.
2) Pellets flow into a heated column where they melt.
3) An auger applies a constant pressure to the liquid plastic to extruder it at a constant rate.
4) A height sensor keeps the filament at a constant height above the ground.
5) The variable speed winder responds to the height sensor to maintain the filament at a constant tension as it cools.
6) A guide arm moves back and forth more and more slowly as more and more filament is wound onto the spool.