Finished building


1 – Send us a picture
It would be really great if you could share a few pictures of the things you made here in the community.This is SUPER valuable feedback for us and probably an inspiration for others

*As an inspiration you can have a look at @mattia-io post on his Hacked Extrusion Machine. We love long and detailed articles like that one but we’re generally very happy to see even shorter version with a few images, reflection and considerations.

2 – Join the Precious Plastic map
We started to gather all worldwide development. Add yourself so others can find you!

3 – Show off
Use hashtag #preciousplastic to share your updates on social media, we love to see this!

3 – Sell on the bazar
Sell you products, machine parts or entire machines on our online bazar. Start your little business around plastic recycling 🙂 visit


Gruppo lame ✅

Hello! I am new here, I want to know where you can buy the components for the processing machine.

@renanfablabnewton can you open a dedicated topic for your question ? this post is for ‘finished’ builds. thanks, also try to use the forum search.

Hi everyone! We are eager to build the shredder and the extrusion machines. We have 2 electric motors, both with 0,75kW and 1725 RPM. Worm gears are pretty expensive around here in Brazil. Any of you have the experience about building a reduction by yourself? Using chains, or pulleys or something like that?


Thank you all!

@malyboa, happy to seeya back in the forum, congrats! i think we could need your help on the extruder → filament story sometime soon 🙂 will ping you via pm.

hours: 40
power: 0.75kw at 20:1
machines: lathe & CNC/Mill, drill press, angle-grinder (3000e)
skills: advanced but not expert
materials : 300e for Motor/Reducer, 70 Speed Variator (VFD), 50 for the Chrome, 30 for the brass adapters, 100 for the heat bands, 15 for the small stuff, 20 for the aluminium, 5 for the drive shaft, 40 euros for electricity, 20 for PIDs & SSRs,  20 Euro for standard suppliers such ass grinding papers (lots), drills, …
in bazar : yes, see “catalonia connection”

hello, please send me info about machines, step-by-step. specifications…i want to built on my own. thanks

HI I’m looking for some information about extruders?
how to make one?
I just saw Dave Hakkens video but I couldn’t download the technical information.

Good day people.

I need to start recycling too.
I need a supply of the four machine.
If possible I would also want to join Plastic V4 war,From Mozambique.

Looks very pretty!


I like the use of a bearing between the arm and push-rod, there’s a lot of force on all the pivot points and this will reduce wear, especially with aluminium. But that little bolt it’s connected to looks like it will just bend backwards, have you tested this?

Nice work! Great idea with the aluminum channel frame. That motor and worm-drive are nice an quiet.

@xxxolivierxxx Do you think I can improve it by using A4-80 steel screws and add something under the side blades to hold it up?

@simeng do you mean that the shredder’s enclosure is not made out of steel? if that’s true then I don’t think there’s much you can do to solve your bending problem. The frame is meant to absorb a great amount of the shredding torque so wood or other non-ferric materials will hardly resist the forces generated when shredding


I built a shredder in International School of the Hague. It took me two years. The box and framework are not steel though, because we don’t have any equipment to work with metal in school. But it works! (Apart from 3mm thick acrylic, the screws which hold side blades are bent after shredding) Is there anyway to prevent the screws from bending?

@faridahmadsofizada part of it is because the oven has to be preset to the right melting point temperature. If you overheat the oven, plastic will melt faster and will also burn producing toxic gases.

Also, you want to take your time to make sure the plastic flows to every corner of your mould.

Hi dave, thanks for this big project.
I wanted to ask something about compression:
Why does the compression process take so long. Is that because oven heats up slowly or what?

hi all. last week we started building the precious plastic machines (shredder, extrusion and injection molder) with a dozen art and design students. the injection molder is now working, the shredder and extrusion machines should be done next week. you can see our current status at: or follow us at for the next steps… best from germany! aart & team

I actually think Dave’s V2.0 shredder is a very good balance of simplicity and performance, which is what you want for an open source anybody-can-build-it design. Of course you can always make improvements, but a lot of them are down to personal taste and wouldn’t suit everybody.

I built my shredder just to suit my own needs, not to propose it as a better version PP shredder. I think it would be less suitable as it’s more technical and contains some custom components that the average person would not be able to make/buy. Some of the ideas I’ve used people might like to incorporate into their own machines as add-ons to the basic design. I think the best way is to take something simple and adapt it to suit yourself using what resources you have available.

I would love to see the double-axe design of andyn make it to the next version of the PP-Shredder. Very goog job. I still beleive though that the motor is too weak. Profressional small size shredders (feed-port-dimension 110mm x 180mm, so slightly bigger than the PP-Shredder) are powered with a 2.2kw motor. I would be mad if i put all that effort in building a shredder, which clogs with milkbottles. But then, the revverse-procedure is very intelligent.