Filament Pelletizer Cutter, Pellet Maker, Filament Recycle

thingiverse

This device turns 3D printing filament into uniform pellets. Produces about 2 to 3 kg/hour of 1.75mm pellets or 6 to 7 kg/hour of 2.85mm pellets. I built this pelletizer entirely from parts I had on hand, with the exception of the 3D printing housing, of course. It uses a 1/2 inch four flute end mill (or two flute if you wish to produce longer pellets) (McMaster-Carr part# 8918A53) as a cutter. This end mill is supported by two R8 2RS ball bearings. (McMaster-Carr part# 60355K704) You may have to sand the ID of these bearings just a touch to allow them to slide easily onto the end mill. The filament is fed into the pelletizer by a 3D printer Bowden drive. The stepper on this drive is controlled by an Ardunio Mega running a a4988 Polulu stepper motor driver on a RAMPS board. (Any stepper motor driver set up will do.) The filament transport tube and fitting on Bowden drive have been removed and the hole drilled and tapped for M8. A ~30mm M8 threaded rod was center drilled with a 3mm drill to make a hollow tube. This tube connects the Bowden drive to the pelletizer. The threaded rod is screwed into a tapped hole in the side of the pelletizer housing and is adjusted to _just_ touch the side of the 1/2 inch end mill. A nut is tighten on the rod against the housing to hold this adjustment. A second nut is threaded on the rod and then the Bowden drive is threaded on the rod. The second nut is tightened against the Bowden drive to hold it in place. I used a 1/12 HP (60 watt) variable speed motor I had on hand. You can edit the flange on the housing file to suit whatever motor you may have. A drill press or a 1/2 cordless drill could be used. Even motor from a desk fan would likely do. I have provided the housing file in STP, STEP, and Inventor IPT format so you can modify the motor flange to suit your specific motor. I made a simple motor coupling by boring a 1 in aluminum rod to fit the motor shaft and the 1/2 end mill. I then drilled and tapped a few holes in the side for set screws. It would likely be superior to use a flexible coupling. Select almost any flexible coupling to suit your motor shaft and to connect to a 1/2 inch end mill. You need to control the speed of either the motor or the Bowden drive to set the pellet size to some reasonable length. >>>>> Why make pellets from 3D filament??? <<<<< It turns out there are a lot of reasons to chop up filament. If you are extruding your own filament, you get filament that just doesn't come out quite right. It might be a bit to big or small in diameter, or the color is not quite what you want. You might also wish to create your own "master batch" to color your filament or your injection molded parts. You mix pigments and blend this with plastic in your extruder, then pelletize the resultant filament to make pellets with the exact combination and concentration of pigment you want. You can remix the pellets so the color is more evenly blended if need be.