Plastic Pellet Maker

Getting custom colors for my desktop injection molding machines is a challenge. Most production injection molding machines use a screw to mix and compress (and heat) the plastic before injection. Those machines allow you to use raw plastic along with a colorant called masterbatch to create just about any color you want.

But my machines are plunger-style machines, and therefore do a very poor job mixing the masterbatch into the raw pellets. So I hatched a plan to use a Filastruder to extrude custom filament and then chop it into pellets.

I started by creating the chopper (I still haven't built the Filastruder, for reasons I'll explain below). I have videos below that take you through my development process until the final version.


You can download the STL (for 3D printed parts) and STEP (for machined parts) from here:


Most of the following links are all "Amazon Associate" links, which means I get a small amount from Amazon. This supports my efforts in a small way without any cost to you.

Development Videos

Pellet Maker Part 7

This is the final version, which uses aluminum parts instead of 3D printed parts for the frame (the 3D printed parts tended to break easily). I've chopped quote a few roles of filament using this version.

Pellet Maker Part 6

I create 3D-printed parts that allow for precise speed control of a Chicago Electric 98179 corded drill (available from Harbor Freight). I also ground flats on the shaft of the forstner bit so it doesn't slip in the drill chuck.

Pellet Maker Part 5

This is the episode where I ground a back relief into the forstner bit. This also goes over the wiring for the stepper motor controller I used.

Pellet Maker Part 4

Pellet Maker Part 3

Pellet Maker Part 2

Pellet Maker Part 1


  1. Great work am looking to start a plastic recycling business knowing it can be done is nice though I can't understand any of the gadgets


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