Shredder Version 2.0

The original shredder we used was a modified one which we found somewhere. The outcome of this machine is great (image attached.) However we need to have a DIY version which is easy to re-build anywhere in the world…

There are different techniques to shred plastic. We’re going to prototype and find out.
Here some interesting videos we came along of shredders
shredder 1 shredder 2 shredder 3 shredder 4 shredder 5 shredder 6 shredder 7 shredder 8

First drawing of the shredder. Using low speed and metal blades to shred the plastic into small pieces

This topic got waay to long. So i’m closing it. if you have another question, feel free to start a new topic. This makes it much easier to keep track of them.

Hi Dave,

I was wondering if you could indicate the cost difference in mild steel vs. stainless blades for the grinder? Also is there much difference in water vs. laser cut parts?

I presume stainless would last longer do better etc.

Thanks for your work!

done: http://preciousplastic.com/

Hi, How close are we to final drawings for the shredder? My entrepreneur in Kenya has successfully pitched for 40,000KSH to have the machine built locally!

@davehakkens Hi, i’m from Chile, along with a friend we got inspired in your project, and we want to do something similar: we want to recycle plastic waste. We´ve done some tests, but the the greatest difficulty that we found was the way to crush the material. We looked at some crusher designs, but they are to small. When will you free the design 2.0 of the crusher, so we can use it.
Greetings from Chile

Hi, i’m from Chile, along with a friend we got inspired in your project, and we want to do something similar: we want to recycle plastic waste. We´ve done some tests, but the the greatest difficulty that we found was the way to crush the material. We looked at some crusher designs, but they are to small. When will you free the design 2.0 of the crusher, so we can use it.

Greetings from Chile

@davehakkens Here in the US you can easily find used treadmills on craigslist that are under $100…there is always the option of ebay but they are a bit more pricey. on ebay you can buy just the motors and controller without having to purchase the whole treadmill (although this is the more expensive option).

haven’t tried it, interesting option though. Not sure if they are easily available, lets find out

@davehakkens Have you considered using the motor and speed control out of an old treadmill? that should have plenty of power and speed range

Maybe an input out of arms reach of the blades is in order?

Not mounted on a bike yet. But we did build and test it to shred by hand, which seemed the most difficult one to achieve. But we got that one. so i’m sure bike wouldn’t be a big problem.

@davehakkens have you tried this final set-up with bicycle peddle-power yet? I want to put your V2.0 on a sailing boat crossing the pacific so they can reduce volume of plastic as they pick it up, but the won’t have enough power to run this beast of a motor!

Amazing result guys! I love it. Could the strainer be simply held tightly in place with some cross-bars on the bottom? The size of the parts as @lyricalpolymath said do look bigger, would a smaller mesh size just cause more melting problems with pieces circulating for longer in the friction-induced heat?

Thanks for the feedback and pictures @nieldefize. hehe still some fine-tuning to do there!

Make a protection cap without any screws or bolts that may come off

Usually we have a different kind of input (welded, without bolts/nuts) this one was made last minute for safety reasons for you guys in Delft. Didn’t suspect the bolts to fall out thought. Probably a nut with rubber inside prevents this.

Add a button with which the shredder can turn the other way

Definitely!

Make it easy to remove the strainer so that the plastic (or unwanted parts) can be removed.

This was already our ‘easy to remove’ version. But can always be easier! Do Let me know if you have suggestions

Make some sort of cooling system so that the plastics won’t melt an get stuck.

Not sure if cooling would be the most effective way, perhaps a simple change in the blades setup (not a spiral) prevents the plastic from moving into on area,heating up and sticking together. Will do some test.

See you on Friday!

congratulations! Awesome result and project!

the pellets produced by this grinder V2 look much bigger than the ones produced with the industrial grinder.

  • – what is the effect of using these larger strips of plastic in the other machines?
  • – what happens if you grind again the plastic? does it get smaller?

I’ve seen a link to this refilamenter machine by redetec somewhere else on these forums, and I think that their design can inspire some modifications for the grinder too.
They say it’s open source.
Apparently they are using counter rotating blades very similar to your design

redetec grinder

what is the approximate cost of your grinder /shredder V2?

thanks in advance

Amazing result, can’t wait to try making one of this ! thank you guys

I can see the shredder takes little ‘bites’ from the plastic. Maybe you should look at how many force is needed to take those bites and try to make it work with like a washing machine motor or other motor that is available around the world. If these motors are not powerful enough maybe look at some gears to do the trick?

I don’t know but you could look on Marktplaats or ask at that plant you got the oven from. Maybe they got something for you