[Jason Knight], an intern at FabLab RUC, has worked hard for 9 months to make a sheet plastics shredder for HDPE and LDPE from things like plastic bags, bubble wrap and air cushion packaging with the goal of recycling the shredded plastic. Why shred these things? When broken down to smaller pieces they can be melted in a consumer grade oven (like where you cook your frozen pizzas) then molded into new objects or extruded into 3D printing filament.
We especially like his big homemade 1.1 inch (30mm) thick wooden gears, for transferring the rotation from the motor to the cutting shafts while giving a step up in torque. As you can see in the video below, the gears definitely add an extra look of power to the machine.
The blades are the shape you most often see in shredders, gear-like disks side-by-side with teeth cut from them that pull the plastic in while shredding it (in contrast to this lower-throughput experimental DIY shredder made with two steel pipes). [Jason’s] multiple teeth are a bit of work to fabricate — not only were all the teeth milled from sheet metal but they then had to be individually sanded to remove burrs from the edges. It was worth it, as this has no problem chewing waste plastics to pieces.
Shredders can be dangerous machines for wandering fingers so [Jason] added a few safety features. Those include a drawer that you open to insert your plastic into the shredding area and a guard that completely surrounds the gears. And both features include transparent plastic areas so that you can still watch the impressive working parts in action.
Continue reading “Scratch-Fabricated Plastic Gobbling Shredder Brings Recycling Home”
Saturday was the first Madison Mini Maker Faire. In this case, it’s Madison, Wisconsin (sorry Madison, SD I didn’t mean to get your hopes up) where I live. Of course I’m not the only crazy hardware hacker in the area. As soon as I got there I almost tripped over Ben Heckendorn who also lives in the area.
Check out that incredible Giant Game Boy the he was exhibiting. Okay, you think to yourself: Raspberry Pi and an LCD. Wrong! He’s actually using an FPGA to drive the LCD. Even cooler, it’s using an original Game Boy brain board, which the FPGA is connected to in order to translate the handheld’s LCD connector signals to work with the big LCD.
Continue reading “Madison Maker Faire”
Walk on almost any beach or look on the side of most roads and you’ll see the bottles, bags, and cast-off scraps of a polymeric alphabet soup – HDPE, PET, ABS, PP, PS. Municipal recycling programs might help, but what would really solve the problem would be decentralized recycling, and these open-source plastics recycling machines might just jump-start that effort.
We looked at [Precious Plastic] two years back, and their open-source plans for small-scale plastic recycling machines have come a long way since then. They currently include a shredder, a compression molder, an injection molder, and a filament extruder. The plans specify some parts that need to be custom fabricated, like the shredder’s laser-cut stainless steel teeth, but most can be harvested from a scrapyard. As you can see from the videos after the break, metal and electrical fabrication skills are assumed, but the builds are well within the reach of most hackers. Plans for more machines are in the works, and there’s plenty of room to expand and improve upon the designs.
We think [Precious Plastic] is onto something here. Maybe a lot of small recyclers is a better approach than huge municipal efforts, which don’t seem to be doing much to help. Decentralized recycling can create markets that large-scale manufacturing can’t be bothered to tap, especially in the developing world. After all, we’ve already seen a plastic recycling factory built from recycled parts making cool stuff in Brazil.
Continue reading “Think Globally, Build Locally With These Open-Source Recycling Machines”
Legend has it that Henry Ford would send engineers out to junkyards all over the US looking for Fords. They were supposed to study each one they found and make note of any parts that had not failed. But it wasn’t so that he could start making all of those parts stronger. Instead, Ford allegedly used this data to determine where he could cut corners in future production runs so as not to waste money by making any part last longer than any other part.
Most things tend to break down rather than completely giving out. Usually it’s only one or two components that stop working and the rest of it is still serviceable. And this is a good thing. It’s what lets us repair PCBs or scavenge parts off them, drive our cars longer, and help save each other’s lives through organ donor programs. Can you imagine how different life would be if each part of every thing failed at the same time?
Continue reading “One Hoss Shay and Our Society of Obsolescence”
All over the world, mountains of polyethylene terephthalate (PET) plastics are available for recycling in the form of soda bottles. And wherever there is enough cheap raw material, a market is sure to emerge for it. One brilliant inventor in Brazil has decided to capitalize on this market by building a magnificent factory to turn PET bottles into threads, rope, and other products.
Not a word of English is spoken in the video, and our Portuguese stops at obrigado, but you don’t really need to understand what’s being said to know what’s going on. Built from what looks to be the running gear of several bicycles and motors from various cast-off appliances, our nameless genius’ machines slit the PET bottles into fine threads, winds the thread onto spools, and braids the threads into heavier cords. We love the whole home-brew vibe of the machines; especially clever is the hacked desk calculator wired to a microswitch to count revolutions, and the salvaged auto jack used to build a press for forming the broom heads. All in all it’s a pretty amazing little factory cranking out useful products from zero-cost raw material.
We’d love to have more context about what’s being said in the video, so we’ll put this one out there for our Portuguese-speaking readers. Maybe we can get a partial translation in the comments? If so, then obrigado.
Haven’t you heard? You can make your own 3D filament nowadays from plastic granules (10X cheaper than filament), or even by recycling old plastic! Except if you’re recycling plastic you will have to shred it first…
[David Watkins] came up with a different way of shredding plastic. Typically we’ve seen shrunken versions of giant metal shredders used to dice up plastic into granules that can be melted down and then extruded back into filament. These work with a series of sharp toothed gears that kind of look like a stack of circular saw blades put together inside of a housing.
But that can be rather pricey. [David’s] method is super cheap, and you can do it at home with minimal tools, and maybe $10 or less worth of parts?
Continue reading “A Different Kind of Plastic Shredder for 3D Filament Making”
When most people think of 3D printing, they think of Fused Deposition Modelling (FDM) printers. These work by heating a material, squirting it out a nozzle that moves around, and letting it cool. By moving the nozzle around in the right patterns while extruding material out the end, you get a part. You’ve probably seen one of the many, many, many FDM printers out there.
Stereolithography printing (SLA) is a different technique which uses UV light to harden a liquid resin. The Chimera printer uses this technique, and aims to do it on the cheap by using recycled parts.
First up is the UV light source. DLP projectors kick out a good amount of UV, and accept standard video inputs. The Mitsubishi XD221u can be had for about $50 off eBay. Some modifications are needed to get the focus distance set correctly, but with that complete the X and Y axes are taken care of.
For the Z axis, the build platform needs to move. This was accomplished with a stepper motor salvaged from a disk drive. An Arduino drives the motor to ensure it moves at the right rate.
Creation Workshop was chosen as the software to control the Chimera. It generates the images for the projector, and controls the Z axis. The SLA process allows for high definition printing, and the results are rather impressive for such a cheap device. This is something we were just talking about yesterday; how to lower the cost of 3D printers. Obviously this is cheating a bit because it’s banking on the availability of cheap used parts. But look at it this way: it’s based on older technology produced at scale which should help a lot with the cost of sourcing this stuff new. What do you think?