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Looking to Construct a Shredder out of Plastic!

This topic contains 3 replies, has 2 voices, and was last updated by  Tyler Linner 2 days ago.

Tyler Linner tylerlinner

Looking to Construct a Shredder out of Plastic!

02/09/2018 at 05:40

Hi everyone,

I am a graduate student pursuing a Master of Arts in Sustainable Communities at Northern Arizona University in Flagstaff, Arizona, USA. My thesis project is centered on the circular economy, and I feel Precious Plastic is a great tool to explore this.

I’m researching the feasibility of building a Precious Plastic shredder while replacing as much steel as possible with cheap recycled plastic. The idea would be to reduce the cost of new shredders as well as put our plastic waste to a good use.

I have secured $7500 in funding through two grants (NAU Center for Ecosystem Science and Society and the City of Flagstaff) and one private donation. This has paid for a human powered shredder, compression oven, two molds, and an extruder, along with minimal wages.

I’ve got the shredder mechanism from Precious Plastic USA and will be ordering the extruder soon. The shredder will be mounted onto a Schwinn Exerciser stationary bike converted to 4.6:1 gearing (28T to 28T then 14T to 65T). I am working with the local bike shop to make that all work on the stock flywheel. I also got a used oven from Habitat for Humanity and will soon have a car jack from my uncle. I got the same oven controller that is used in the Precious Plastic build video. I’ve also been collecting discarded bed frames for building tables. It’s looking pretty good!

Anyway, I wanted to reach out to you all and let you know what I’m doing. I’ve got a potential source for ABS locally, which I suspect will be a good start for building the shredder parts. Of course the blades will still be steel.


Check out my progress at the Praxis Plastics blog! I would love to work with a machine builder (ahem Justin) or even Precious Plastics itself. I would also love to be involved in prototyping V4 using plastic parts! So please let me know if there is any interest. My school email is [email protected].

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05/09/2018 at 06:37

Hey @tylerlinner,
Your project seems very interesting, I wish you all the best, and congrats on the funding. I will be closely following your progress. Make sure you post regular updates to this forum as well as your blog! 😀

I currently have an exercise bike I too would like to convert, but for now, the hand-cranked version is what we use.


09/11/2018 at 01:19

Hi all,
Quick update. I don’t know if image uploading is working so I’m adding links too. Shredder is almost done. Here is a video before the chain tension has been figured out.

Oven is 95% done now as well. Just need to find a control box, mount the controls, and also possibly move the thermocouple.

As I await the shredder’s completion, I am working with the shop that worked on the oven to build a sheet mold based on this: https://davehakkens.nl/community/forums/topic/slow-molding-sheet-making/

The idea is to  experiment with making multiple sheets of different materials and thicknesses, and building a shredder out of them! No idea how it will work.

16/11/2018 at 21:50

Shredder is home. It’s working but needs some tweaks to be ready to do real work. The main issues are gearing and a too-light flywheel. I’ll be investigating today. To avoid copying/pasting everything, check out my blog for the rest of the updates:


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