Simple Filament Pelletizer

Uses a 7/16" drill bit, small piece of aluminum bar stock (available at lowes), drill press, C Clamp and Chinese soup container to chop up filament. Also needs 4 M3 X 25 mm bolts with nuts/washers. Most of the pellets come out real small, some are longer, but still mostly broken so they break easy in your hand. If the piece of metal was brought closer to the drill bit the larger pieces would probably be eliminated, but at the risk of any drill bit wobble making metal bits (experiment and let me know what you find). A drop of mineral oil prevent heat build up from the shaft of the drill bit rubbing along the plastic. Move the devices all the way up on the drill bit so the cutting section stops below where the abs rubs the drill bit. If you don't, pellets will ride up into this cavity and generate heat and melt, causing issues.

One benefit of this design is that its very easy to remove the piece of metal and examine it to be sure there has been no metal shavings created.

Update #1: If you chamfer the hole in the aluminum bar with a larger drill bit, the filament will feed much easier. Without this, filament with bends/curves can catch on the edge.

Update #2: I drilled it out to 1/2" so there is less space between drill bit and the aluminum piece. If there is too much room, abs won't chip, it just chews at it and leaves it intact. I found it works much better if you actually use push to connect fittings. Tap the aluminum block and drill out the upper plastic piece so the fitting fits. I also finally got my setup motorized. See video: https://youtu.be/G9oXTAJCpPA