Vicious Little Desktop Shredder Pulverizes Plastic Waste

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.

Continue reading “Vicious Little Desktop Shredder Pulverizes Plastic Waste”

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

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.

Continue reading “Shredder Rebuilt From The Ashes, Aims To Produce More Ashes”

Building A Lego Paper Shredder

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.
Continue reading “Building A Lego Paper Shredder”

A man watching money being shredded in a picture frame

Banksy-Like Stock Tracker Shreds Your Money When The Market’s Down

For anyone playing the stock market, and perhaps even more so for those investing in cryptocurrencies, watching the value of your portfolio go up and down can be a stressful experience. If you’d like to have a real-time display of your investments that adds even more stress, [Luis Marx] has got you covered. His latest project is a plexiglass case (video in German) that fills up with banknotes when your portfolio is up, and shreds those same notes when it’s down.

Inspired by an infamous Banksy artwork, [Luis] began by building a wood-and-plexiglass display case suitable for hanging on the wall in his office. He then installed a small paper shredder, modified with a servo so that it could be operated by an Arduino. Unable to find an off-the-shelf banknote dispenser, he designed and 3D-printed one, consisting of a spring-loaded tray and a motor-driven wheel.

A plastic box that dispenses a banknote

The project also includes a Raspberry Pi, programmed to fetch market data from online sources and calculate the net profit or loss of [Luis]’s portfolio. The resulting system is a rather disturbing visualization of the ups and downs of the market: having to sweep strips of green paper off your floor adds insult to the pain of losing money.

If you want a less painful way to keep track of your investments, try this Rocketship. For those interested in  traditional stock tickers, this ESP32 based one might be more to your liking.

Continue reading “Banksy-Like Stock Tracker Shreds Your Money When The Market’s Down”

3D Printer Lets You Play “Will It Shred?”

[Brian Brocken] is at it again, building mechanisms that are as striking in their aesthetic as they are in their function. This time around, he’s extended a project we recently featured by adding a menacing 3D-printed shredder attachment. When you hear “3D-printed shredder” you think that paper is all you’ll be able to feed it, but this beast can eat its own by shredding parts from failed prints.

His original goal in building the high-torque 3D-printed gear box we looked at back in August was to show that 3D printed parts can be functional and not merely decorative. Using it as a winch to pull a car did a good job of that, but this goes much further. The very nature of shredder blades is to tear apart objects, but the forces that destroy those things are also present on the shredder parts themselves. Still, as you can see in the video below, the counter-rotating twin-shaft shredder mechanism does its work without catastrophic damage to the blades which were printed with “least 25 percent infill for the structural parts”, and up to five outer perimeters.

The result is a shredder that can gobble up small pieces of failed prints, in addition to chewing on paper, cardboard, and polystyrene with ease. [Brian] does show a few failures along the way, all in the gearbox itself. The first was a defect in the housing that let an gear shaft pop loose and was fixed up with a reprint. The second is a catastrophic gear failure when trying to shred a soda bottle. This is not surprising as PET is quite tough and not brittle like the waste prints were. The shredder teeth got bogged down, and the power of the motor strips teeth from a few gears. But when working, it’s oddly satisfying to watch that powerful gear ratio chip away at sacrificial materials.

If you’re more on the prowl for a way to usefully recycle your plastics, set the 3D-printed stress test of this one aside and take a look at the plastic shredder Fablab RUC built out of metal and plywood a few years back.

Continue reading “3D Printer Lets You Play “Will It Shred?””

Banksy’s Barely Believable Batteries

Nearly a decade ago my friend [Dru] gave me an unforgettable tour late at night of Stokes Croft, the inner suburb of Bristol known at the time for its counterculture and artistic scene. It’s a place dominated by building-sized graffiti and murals, and it has a particular association with the Bristolian street artist [Banksy]. If you’ve not seen a Banksy in the wild, the place to do it is by Bristol Saturday night street lighting to the sound of passing revelers and traffic on the A38.

[Banksy] is famous aside from his anonymity, for his pranks upon the art world. The (real) elephant in the room or the Dismalland theme park are his stock in trade, and you may have seen another prank of his in the news in the last day. One of his paintings, the 2006 Girl With A Balloon sold at auction for over a million quid, and as the gavel fell a hidden shredder in the picture frame sprang into life and partially shredded the canvas. The report suggests that a number of [Banksy]’s associates were present at the event, and that one of them was detained with a device that might have been a remote control trigger for the shredder. The quote from Sotheby’s Europe head of Contemporary Art, [Alex Branczik] says it all: “We got Banksy’d”.

The interior of the Banksy shredder frame, taken from a frame of the video.
The interior of the Banksy shredder frame, taken from a frame of the video.

[Banksy]’s cool and all that, but where’s the hack? The artist briefly put up a video with a few details, but aside from showing us a row of craft knife blades and a tantalizing but fleeting glimpse of a few equipment enclosures, it’s short on technical details. We can see what appears to be at least one motor, and those white boxes may be batteries, but that’s it.

This hasn’t stopped some fevered speculation as to how the feat was achieved. A home-made shredder would require a significant amount of readily available power, and since this one has seemingly lain undetected within the frame since 2006, that power source needs to have possessed both exceptional  energy density and retention. We can’t imagine many consumer grade batteries in 2018 being able to retain a charge for twelve years, so how on earth did he do it? Our best guess is that a primary battery was involved, as anyone who has found a neglected Duracell in a box of electronics from their youth will tell you it’s not unknown for decent quality alkaline cells to live well beyond their shelf lives, and other chemistries are specifically designed with that property in mind. Even so, for the cells to power a receiver circuit in standby for so long would certainly tax their capabilities, so it has also been suggested that a concealed switch could have been flipped by a [Banksy] accomplice during the viewing phase to activate the system. There are still so many unanswered questions that it’s certainly piqued our technical curiosity. Sadly we don’t know [Banksy] to ask him how he did it, but we welcome speculation both informed and otherwise in the comments.

Our own [Joe Kim]'s tribute to the work in question.
Our own [Joe Kim]’s tribute to the work in question.
Meanwhile the piece itself lies half shredded and protruding from the base of the frame. On the face of it that’s ruined the painting as an artwork, but of course this is a Banksy. Normal rules seem not to apply, so the notoriety it has received will no doubt mean that its shredded remains are an artwork in themselves, and possibly even one worth more.

Banksy owners worldwide are no doubt now paying a huge amount more attention to the artist’s frames than previously, but Hackaday readers need not worry. Our London Unconference logo and stickers featured a [Joe Kim] homage to the Banksy in question, which we can guarantee does not incorporate an artist’s shredder.

 

DIY plastic shredder with gears and safety

Scratch-Fabricated Plastic Gobbling Shredder Brings Recycling Home

[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”