Precious Plastics Builders Meetup


This is great news @rustyfundi!

Now we need community assistance with machine redesign for motor re-use.


Many thanks @rustyfundi! That means we’re covered for the frame, we’ve got a rough cost of the motor down to ~35,000 KSh, and I hear the laser cutting of the stainless steel is coming to ~35,000 as well. Add the electronics and other incidentals, and we’re looking at a total cost of ~100,000 KSh?

Unfortunately, this does seem to match what I’ve found digging deeper into the Precious Plastic project details. The rough costings provided with the videos don’t seem to match reality. Most people on this thread say their build has ran from 700 - 1000 Euros:

I think we can definitely get those costs down if we reconsider some crucial elements of the design:

  1. Reusing one motor to power multiple machines
  2. Using a smaller motor, depending on the type of plastic we want to be able to shred
  3. Using mild steel instead of stainless steel for the shredder knives

There’s a lot to reconsider here, so I think our next meeting (on the 17th) will need to be more of a design discussion than actually building the thing.


Yeah. I agree. The costs are getting high. Let’s meet up and see if we think we can redesign the other machines to run off of one motor.


Awesome, I believe that’s a solid agenda for this weekend’s meetup - to review the equipment and redesign for motor reuse …

Hopefully we can also inject some rigor into the process by adopting a structured approach


Meetup is this saturday, let meet to redesign and think through the models.


Hey, what time’s the meetup?


Hey Clement,

10:00am to 1.00pm.

See you then.


Thanks, see you then.


Its was a pleasure meeting with you guys. very interesting conversations. Am looking forward to more things to come. Looks like work is now cut out. Thanks


Hi all,

Thanks again everyone for coming and contributing on Saturday! I’m really excited to build this thing.

Like we discussed, I’ll handle the finances and overall coordination. To that end, I’ve put together a Google Sheet to track everything. On it, you’ll find:

  • My contact info. Don’t hesitate if you have any questions, or need to send me mpesa.
  • The schedule. We’re looking to assemble in two weeks!
  • The teams and roles we agreed to yesterday.
  • A link to specific forum topics for each team (knives, motor/gearbox, etc.).
  • The budget and finance tracking (on a separate tab).


Hi all! Excellent meetup today. We have our motor, gearbox, and electrical box all ready to go. I took the liberty of taking measurements of each of them to help with drafting the frame (I shared these in the frame discussion, too).


The pieces remaining to be procured are:

  1. A 12" pulley to connect the motor to the gearbox
  2. A belt for that pulley
  3. A couple to connect the driveshaft to the gearbox
  4. The driveshaft
  5. The knives
  6. The frame and hopper

The knives team are still working on sourcing material to determine if it will be cheaper to machine it ourselves or to have it laser cut at Pipeman’s. The frame team can start designing that using the dimensions above.

We haven’t set a date for the next meetup, but I’ll follow up shortly both here, on Gearbox’s main website, and on as soon as we know a bit more about the timeline for the knives.

A huge thanks to everyone for coming together and building something amazing!


hi guys sorry I have being missing in action school has me tied down…
Anyway I have a friend who is looking for a plastic plate with the dimensions below…
3m x 2m x 0.15m

If anyone has an idea on the price and where to get it it would be really helpful…
Thank you and have a blessed day


That’s a massive plate, @dunkan502! What kind of plastic do you need? I’ve bought 8’x4’ sheets of acrylic before, but never thicker than 15mm.


I don’t know of a place which stocks such massive plastic. May be if i knew the application i could recommend alternative material


Hi everyone, I’m very happy to be able to join your group!
Brief info about me: My name is Katharina Elleke and I’m studying industrial design in Munich.
This semester (so since October) I am in Kenya doing a project about waste and recycling and when I figured out that shredder is quite a big issue and started researching - I found you!

Can someone tell me shortly, what still needs to be done and if the next meeting is in sight?
Best regards!



Is anyone still active on this?

Mattia from Precious Plastic.
We would need a little parts built for a partner in Kenya.
We’re looking for the lathed axe for the shredder.

Anyone able to help us with that?
Job would be paid.

Let us know.


Hello Mattia, yes we are still working on it.

We are aware that we needed 15 knives and our team is making the rest of the knives.

However we still need the pulley belt,a couple to connect the shaft to the Gearbox among others.


The precious plastic project is still on!!


Hi Brenda, it was great meeting you a few days ago and glad that the plastic project is still on. Is anyone who is interested free to do a Meetup soon?

Also I’m looking at building a shredder soon, so if anyone is interested in collaborating/building one, let me know :slight_smile: