David Watkins is a Pennsylvanian maker and 3D printing enthusiast who’s skilled in electronics, mechanics, kinematics, and data analysis, and he wanted to take on a problem he faced after purchasing his printer – the ongoing cost of materials.
Watkins says that while 3D printers continue to decrease in cost, “purchasing plastic filament still remains a costly affair.”
He was taken by the ongoing efforts in the 3D printing community to produce filament, and he was struck by the number of companies and individuals who have designed filament extruders. He believes that at some point, there will be “settings and methods for printing (which) will allow for almost any type of plastic to be used, making any recyclable plastic a source of printing material.”
“If a person could shred waste plastic or failed prints to feed into an extruder, the cost of printing material would be greatly reduced,” Watkins says. “Searching the internet reveals some impressive and well-built plastic shredders, but the complexity and cost are significant.”
So Watkins took on the task of building and documenting “a proof-of-concept of a simple, low-cost, hand-operated plastic shredder for starting the process of reusing waste plastic for printing.”
Most of the structure of the shredder is composed of wood, and a few pieces of pipe and some readily available tools are about all you need to make it happen in your own garage or workshop.
It’s a pretty simple design in which two pieces of steel pipe are set up coaxial and used as the cutting mechanism. As the outer cylinder remains fixed in place, the inner cylinder rotates within it and a slot cut into both cylinders acts as both a blade and a hopper. By mounting the cylinders on an incline, Watkins says the milled pieces can fall through the cylinders and into a collection container.
According to Watkins, the whole project’s tools and materials are so cost-effective the project can effectively be free, or very close to it:
“Depending on what tools and materials you have on hand, or your level of resourcefulness, this device can be built for anywhere from free, to about $30!”
You can check out Watkins’ Instructable project here for full details on how to create your own shredder.
Will you use David Watkins’ design for a plastic shredder or can you refine his idea for a design of your own? Let us know in the Home Built Plastic Shredder forum thread on 3DPB.com.