Large-format flake-extruding 3D printer prototype

Hi all, for the past year or so I’ve been working on a large format, low resolution 3D printer that can print directly from recycled plastic flakes from the shredder, as an alternative to making filament. I keep forgetting to actually make a post about it here, and it’s about time I did!

There’s still a lot to do, but initial tests have been very promising! I am convinced that this can be done well and at low-cost.

More info/documentation can be found at:
Sketchup 3D warehouse Model
MPCNC documentation
Amazon Buy-list (use a reference, you can get most parts locally)

Cost to build: $500, +/- $100
Nozzle size: 3-4mm
Software Used: Repetier-Host
Control Board: Rambo 1.4 from V1 Engineering

Basically I just built an MPCNC and then strapped this extruder I designed onto it. It’s pretty ugly, but it works at least as a proof of concept. I’ve not tested it very much, but one major discovery I made is that I can use cheap 4mm coroplast (corrugated polypropylene) sheets as the build-plate. This eliminates the need for a custom heated bed to get good adhesion, since PP is highly self-adhesive.

We did one layer-test, and it seemed like thermal-warp was a bit of an issue, but the final “part” was VERY solid and VERY strong, which is promising. Desktop 3D printing is already highly advanced for small, highly detailed parts, and in my opinion doesn’t lend it’s self well to the limitations of recycled material.

So instead my goal is be able to 3D print large, relatively low-resolution, but still geometrically complex 3D objects, on the scale of furniture, bike frames, and surfboards.

I will be working to get some better documentation up, but I wanted to make this post to share what I have, and most importantly, to confirm that I think this is possible and worthy of further development. I’m not a 3D printer person so my progress has been quite slow, I would love to see others hacking on this!

Sam Smith

Repetier Build Settings for technical folk. Most of these were set by a friend of mine, so they are provided for reference but I probably can’t answer questions about them. Actual size is 2′ x 4′ x 1′, effective build area is about 300mm (X) x 900mm (Y) x 150mm (Z).

@samsmith, please keep us posted. this is pretty much the best achievement since long here, it would pave the way to lots of more precious things 🙂 For now we take your drawings, links, etc… for granted and try to replicate it here. Hope to hear soon from you!
thanks a million

Great work, they look really good.
Definitely interested in giving this a go.
What size mesh do you have on your shredder?

I made some really major progress just in the past few days, and was able to produce my first truly “3D” prints!

The print quality isn’t great compared to desktop printers, but that was never the point. The parts are strong, and light, and flexible, and the prints are fairly tolerant of variations in the size of the bead. There are a lot of things that could be improved, but the system is definitely useful and effective as-is.

The real challenge now is dialing in the settings, and just figuring out what we can print at this scale/resolution that is useful. I just re-did my sketchup model of the extruder, and I’ll be posting full documentation shortly. Stay tuned!

Great work Sam.


Been thinking about how to utilise the recycled plastic in 3D printing. I had started to look at first making pellets and then using a pellet style extruder – this way inconsistencies in the filament diameter / filament manufacturing process could be eliminated. I had not considered using flakes directly in the 3D printer extruder due to size inconsistency.


Did you find much variation in the extruded plastic size?


Would it be possible to print some test pieces to measure print quality? I generally print cubes for setting up printer geometry as they are easy to draw, print and measure.




(love your project BTW 🙂 )

wow . I like this concept alot ! Please send updates more and more 🙂

amazing work, thanks for sharing, please keep updating this post 🙂