“An open-source, low-cost, large-format 3D printer that can print directly from shredded plastic trash instead of filament
The Trash Printer is an open-source large-format 3D printer that can print new and useful things directly out of shredded plastic trash. Polypropylene (#5) works best, but I’ve also printed with HDPE and LDPE (#2 and #4) Together, these common plastics make up over 50% of all household plastic waste!
The parts aren’t as detailed as typical 3D printed parts, but they’re incredibly strong, light, and flexible; more comparable to parts made by injection molding than those made by most desktop printers. Skipping the filament-making step entirely reduces the recycling process to just two steps: Shred, and Print.
Version 3 Overview:
Estimated Build Time: 12 hours
Estimated Cost: $1000-1500 or $3000-3500 with solar power
Energy Cost: About 1 watt-hour per gram
Print Area: V3: 22” x 14” x 22” V3 Mini: 8” x 16” x 22”
The Trash Printer was inspired by the Precious Plastic movement, a global, open-source, small-scale plastic recycling movement! It started with 4 open-source machines - a shredder, an extruder, an injection molder, and a compression oven. Since the original designs were published in 2013, a global network of makers has emerged, modifying, improving, and developing the original tools, and adding their own!
The Trash Printer is my small contribution to that global open-source effort. Precious Plastic is one of the most inspiring projects that I know of, and it’s changed the way I look at plastic. For my entire life, plastic was a material that I felt I had zero agency over. I didn’t get to decide what got made out of plastic, and I didn’t get to decide what happened to it after it was thrown away. It felt like all I could do was feel bad about it.
What I love about Precious Plastic is that it’s not about telling people what they shouldn’t do, or what the people in power should do, it’s about what we can do, right now, with our friends and the tools and materials we have around us.
None of the Precious Plastic machines are particularly revolutionary- the technology has existed at an industrial scale for decades. But that technology has always been large-scale, requiring huge facilities, tightly-held patents, highly-specialized skills, and lots and lots of money.
What Precious Plastic did that was revolutionary was take those basic machines and make them accessible to a much wider range of makers, lowering the barriers to entry, by making them smaller, cheaper, and fully open-source, so that people can get together with their friends, and actually DO SOMETHING about their plastic waste, instead of just feeling bad about it!
Like the other Precious Plastic Machines, the Trash Printer isn’t a particularly revolutionary machine. It’s certainly not the first or only pellet/flake extruder or large format printer - I was originally inspired by the RichRap extruder, and the SeeMeCNC Part Daddy, which showed me that printing from flakes instead of filament was possible.
It’s also not the only printer to print with recycled plastic. The PullStruder and PolyFormer Plus can print high-detail parts using recycled PET (#1), and the enormous Bloft MK2 (also inspired by Precious Plastic) can print huge parts! I’ve always wanted print a whole surfboard out of plastic trash!
When you’re up against a challenge as big as global plastic waste, there really isn’t such a thing as competition. The “competition” is the plastic waste problem itself. The waste problem is distributed, and it requires equally distributed solutions, not one single machine or one idea.
Every new open-source tool we can add to our toolkit expands what YOU and YOUR FRIENDS can do with YOUR trash, and ultimately, that’s what Precious Plastic is all about. It’s about what YOU can do about it. The Precious Plastic machines were the first plastic recycling tools that were simple and well-documented enough to make me go, “Hey, I could do that!”
My deepest hope is that the Trash Printer might do the same for you. My primary design goal for this entire project has always been to make the Trash Printer as easy as possible to build, requiring the simplest tools, the most widely available parts, for the least amount of money possible.
I’m not a 3D printing expert, and the Trash Printer was the first 3D printer that I ever built. If you are a 3D printing expert, you can probably tell.
When I first started building the Trash Printer, I knew nothing about how 3D printers worked, and “3D printer people” seemed to possess some magical, mystical, deeply technical knowledge that felt far beyond my understanding.
I didn’t know what I didn’t know, and didn’t know where to start. I didn’t even know what questions to ask. They would say things like, “all you have to do is flash Marlin onto a RAMPS, and then slice an STL into g-code” as if I knew what any of those words meant.
So for this project, I have made every effort, within the limits of my time, budget, and technical skill, to make the Trash Printer as easy for you and your friends to get started as possible; to lower the barriers to entry as much as I possibly can, and make it easier for you than it was for me. 3D printing with plastic trash is kind of an inevitable idea, but it’s an idea that’s only really cool if lots of people can actually do it, everywhere, as quickly as possible.
I call this project The Trash Printer, but it might be better to call it a trashprinter. I want to see trashprinters become common, generic, universal household appliances, like dishwashers. I want our kids to grow up and take the idea completely for granted - “hey honey, can you throw this in the trashprinter for me?”
It doesn’t matter if you use my design, or someone else’s, or if you design your own trashprinter completely from scratch! What does matter is getting as many people printing useful stuff out of their actual trash as quickly as possible.
When a lot of people are engaged in creative problem solving, the impossible can become possible very quickly.
The Trash Printer Version 3 documented here will probably cost you roughly $1000 - $1500 for all the parts new, but many can be found locally and/or used, or scavenged from old 3D printers. The latest V3 Mini build took me exactly 12 hours, over 5 days.
It prints at an energy cost of about 1 watt-hour per gram, or 1 kilogram per kilowatt hour, which means that in most climates, a single 300-400W solar panel will generate enough energy, on average, to recycle 1-2 kilograms of plastic every day, using nothing but trash and sunshine.
It can print all sorts of useful parts- particularly strong, big parts, more comparable to those made by injection molding than by most 3D printers. Considering that most plastic injection molded objects are manufactured in China and shipped across the entire Pacific Ocean, being able to make comparable parts locally, even simple ones, directly out of trash, using only sunshine, is pretty incredible.
Since the material is essentially free, the real benchmarks of performance are the cost to build the machine, the energy it takes to run it, and what kind of stuff you can make with it. Can you lower the cost to build the Trash Printer? Can you make it more efficient? Can you print increasingly useful stuff and share your code, so that we all can too? This is a design challenge that I find endless fascinating, and I invite you to come hack on it with me.
You know that scene in Hackers when all the hackers from all around the world coordinate their skills and knowledge to avert ecological catastrophe and stick it to corrupt and destructive institutions? Of course you do! That’s what Precious Plastic feels like to me in real life.
It feels like a little taste of what we have the opportunity to do with everything - our power, our water, our food, our shelter, our waste - developing and sharing designs for small-scale, open-source, closed-loop infrastructure that puts power directly in the hands of local communities and makers.
Have you ever dreamed of being part of that rag-tag band of misfits who hatch a plan just crazy enough to save the world at the last possible second? Have you ever dreamed of hacking the planet, but for reals? I know I have. And I’m starting to believe it might actually be possible.