DIY Shredder Creates Insulation

October 23, 2023 by Bryan Cockfield 28 Comments

Plenty of us have experience with paper shredders, but there are all kinds of machines designed to completely destroy other materials as well, from metal and plastic, to entire cars. [Action BOX] built their own heavy-duty shredder capable of dismantling things like cell phones and other robust handheld objects, but after seeing what it would physically shred they decided to give it an actual job creating insulation for the attic space in their garage.

The shredder itself uses opposing metal plates arranged on sets of two cylinders, with each cylinder powered by it’s own large motor. In total, the entire system uses around 1.5 kW, so to make their green insulation project as green as possible they decided to power it with an equivalent amount of solar panels. For the insulation they’re using a year’s worth of boxes from various deliveries, and after a time-consuming process preparing the boxes for the shredder, shredding the strips of cardboard, and packaging it in garbage bags their efforts netted them enough to partially fill the space between four ceiling joists. Continue reading “DIY Shredder Creates Insulation” →

Getting Shredded Plastic…and Legs

September 23, 2023 by Navarre Bartz 10 Comments

While electric motors have taken the drudgery out of many tasks, human power has its advantages. [Precious Plastic Torino] has developed a human-powered plastic shredder for those times when an electric motor just won’t do.

Designed primarily for educational purposes at venues where electricity can be difficult to source, but also useful for off-grid environments, this exercise bike-based shredder can take small pieces of plastic and shred them into tiny pieces suitable for use with any of the other machines in the Precious Plastics ecosystem like their injection molding machine. As with all [Precious Plastics] projects, the files ~~are~~ will be open source; however, there is a six month exclusivity period for Patreon subscribers to help fund development efforts.

The build is relatively simple: take an old exercise bike, remove the unnecessary bits, and run the chain up to drive a shredding mechanism mounted on the front of the bike. We think they should’ve kept the flywheel to help keep the momentum going while shredding but can’t fault them for wanting to keep the prototype as simple as possible. Maybe the next step is getting these in spin classes around the country so people can get their exercise and help recycle in their community at the same time!

If this shredder doesn’t suit your fancy, maybe recycle your plastic with SHREDII or this other DIY effort. If you’d rather generate electricity on your exercise bike, then try building this bike generator.

Continue reading “Getting Shredded Plastic…and Legs” →

An aluminum box sits on a workbench. It is open and has a message saying "I Love You!" inserted in a wooden slot. There is a switch with a yellow LED on the front and a small compartment to the left of the wooden slot to store paper.

Share Your Feelings Like A Spy

September 8, 2023 by Navarre Bartz 13 Comments

While hackers can deftly navigate their way through circuit diagrams or technical documentation, for many of us, simple social interactions can be challenge. [Simone Giertz] decided to help us all out here by making a device to help us share our feelings.

Like an assignment in Mission: Impossible, this aluminum box can convey your confessions of love (or guilt) and shred them after your partner (or roommate) reads the message. The box houses a small shredder and timer relay under a piece of bamboo salvaged from a computer stand. When the lid is opened, a switch is depressed that starts a delay before the shredder destroys the message. The shredder, timer, and box seem almost made for each other. As [Giertz] says, “Few things are more satisfying than when two things that have nothing to do with each other, perfectly fit.”

While seemingly simple, the attention to detail on this build really sets it apart. The light on the front to indicate a message is present and the hinged compartment to easily clean out shredded paper really make this a next-level project. Our favorite detail might be the little space on the side to store properly-sized paper and a marker.

While the aluminum box is very industrial chic, we could see this being really cool in a vintage metal lunch box as well. If you’re looking for other ways to integrate feelings and technology, checkout how [Jorvon Moss] brings his bots to life or how a bunch of LEDs can be used to express your mood.

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3D-Printed Shredder Eats Lettuce For Breakfast

March 19, 2023 by Lewin Day 15 Comments

Shredding things isn’t just good for efficiently and securely disposing of them. It’s also very fun, as well. [Joonas] of [Let’s Print] didn’t have a shredder, so set about 3D printing one of their very own.

The design apes that of the big metal trash shredders you’ve probably seen in videos all over the internet. They use a pair of counter-rotating drums with big teeth. As the drums turn, the teeth grab and pull objects into the gap between the drums, where they are duly torn apart into smaller pieces.

In this design, plastic drums are pressed into service as [Joonas] does not have a metal 3D printer. A brushed DC motor is used to drive the shredder. A large multi-stage gearbox is used to step down the motor’s output and provide plenty of torque to do the job.

The shredder gets tested with plenty of amusing garbage. Everything from old vegetables, to paper, and rock-hard old cheeseburgers are put through the machine. It does an able job in all cases, though obviously the plastic drums can’t handle the same kind of jobs as a proper metal shredder. Harder plastics and aluminium cans stall out the shredder, though. The gearbox also tends to strip gears on the tougher stuff. The basic theory is sound, but some upgrades could really make this thing shine.

Is it a device that will see a lot of practical use? Perhaps not. Is it a fun device that would be the star of your next hackerspace Show and Tell? Absolutely. Plus it might be a great way to get rid of lots of those unfinished projects that always clog up your storage areas, too! Video after the break.

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Vicious Little Desktop Shredder Pulverizes Plastic Waste

May 15, 2022 by Dan Maloney 20 Comments

We’ve all likely seen video of the enormous industrial shredders that eat engine blocks for lunch and spit out a stream of fine metal chips. The raw power of these metal-munching monsters is truly fearsome, and they appear to be the inspiration for SHREDII, the miniature plastic shredder for at-home recycling of plastic waste.

The fact that SHREDII isn’t all that large doesn’t make it any less dangerous, at least to things smaller and softer than engine blocks, like say fingers. The core of the shredder is a hexagonal axle carrying multiple laser-cut, sheet steel blades. The rotating blades are spaced out along the axle so they nest between a bed of stationary blades; rotating the common axle produces the shearing and cutting action needed to shred plastic.

On version one of the shredder, each blade had two hooked teeth, and the whole cutting head was made from relatively thick steel. When driven by a NEMA 34 stepper — an admittedly odd choice but it’s what they could get quickly — through a 50:1 planetary gearbox, the shredder certainly did the business. The shreds were a little too chunky, though, so version two used thinner steel for the blades and gave the rotary blades more teeth. The difference was substantial — much finer shreds that were suitable for INJEKTO, their homebrew direct-feed injection molding machine.

There’s a lot to be said for closing the loop on plastics used in desktop manufacturing processes, and the team of SHREDII and INJEKTO stands to help the home gamer effectively reuse plastic waste. And while that’s all to the good, let’s face it — the oddly satisfying experience of watching a shredder like this chew through plastic like it isn’t even there is plenty of reason to build something like this.

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The shredder after being rebuilt, on the bench top, with the washing machine pulley driving it spinning. It has not yet been fed, but that's about to happen.

Shredder Rebuilt From The Ashes, Aims To Produce More Ashes

April 8, 2022 by Arya Voronova 16 Comments

What do you do when you buy a broken shredder and, upon disassembly, find its gears in pieces? You might reach towards your 3D printer – this one’s not that kind of shredder, however. [New Yorkshire Workshop] gives us a master class on reviving equipment and putting it to good use – this one’s assigned to help turn their cardboard stores into briquettes for their wood burner.

But first, of course, it had to be fixed – and fixed it was, the crucial parts re-designed and re-built around a sturdy wooden frame. It was made into a machine built to last; an effort not unlikely to have been fueled with frustration after seeing just how easily the stock gears disintegrated. The stock gear-based transmission was replaced with a sprocket and chain mechanism, the motor was wired through a speed controller, and a washing machine pulley was used to transfer power from the motor to the freshly cleaned and re-oiled shredder mechanism itself. This shredder lost its shell along the way, just like a crab does as it expands – and this machine grew in size enough to become a sizeable benchtop appliance.

After cutting loads of cardboard into shredder-fitting pieces, they show us the end result – unparalleled cardboard shredding power, producing bags upon bags of thinly sliced cardboard ready to be turned into fuel, making the workshop a bit warmer to work in. The video flows well and is a sight to see – it’s a pleasure to observe someone who knows their way around the shop like folks over at [New Yorkshire Workshop] do, and you get a lot of insights into the process and all the little tricks that they have up their sleeves.

The endgoal is not reached – yet. The shredder’s output is not quite suitable for their briquette press, a whole project by itself, and we are sure to see the continuation of this story in their next videos – a hydraulic briquette press was suggested as one of the possible ways to move from here, and their last video works on exactly that. Nevertheless, this one’s a beast of a shredder. After seeing this one, if you suddenly have a hunger for powerful shredders, check this 3D printed one out.

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Building A Lego Paper Shredder

March 11, 2022 by Lewin Day 3 Comments

Sometimes we need to destroy documents before throwing them away for security reasons, and shredders are a primary way of achieving that. If you don’t have your own, you might consider building your own, like [Brick Experiment Channel] did using Lego.

First attempts at shredding a small slip of paper with interlocking gears were a failure, merely crumpling the paper in an attractive rippled manner. As the “Top Secret” piece of paper says, “If you can read this, the shredder didn’t work.” Adding more gears managed to gouge a couple holes in the paper, but it was still far from effective. Continuing down this path further only stalled the Lego motor.

A redesign with different sized gears did eventually manage to tear the paper into large chunks. One set of gears would hold on to the paper while a following set would tear away a section. A further modification combined this method with using bevel gears as a sort of blade, and improved shredding performance further, to the point where the paper was torn into satisfyingly tiny fragments.

It’s a fun little build, even if it won’t come close to taking on a full page of A4. It’s a great example of what can be achieved when you set a simple goal with readily measurable outcomes, in this case, the legibility of the original message on the paper.

We’ve seen a few shredders around here before too. Video after the break.
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