For eons, hacker minded people have looked at various items their pile of stuff, came up with an outlandish idea and thought “I wonder if it would work?” Some of us stop there, convincing ourselves that it’s a bad idea that could never work. Others of us such as [Peter Sripol] are well known for not just having those thoughts, but for having the grit to explore them to their impractical limit, such as is shown in the video below the break.
Peter begins by adapting a model airplane propeller to his 9500 RPM battery powered grinder, and then checks thrust with different propellers to see which seemed most efficient. Then [Peter] did what any aerospace engineer out of their right mind would do: He had his brother design the resulting aircraft, which was inspired by an obscure German WWII asymmetric aircraft design.
Did it fly? It did, and you can see a couple of iterations of it tooling around in the video. But what happened next was equally interesting: First, a grinder powered single bladed helicopter and its subsequent hilarious failure, and its slightly more successful successor.
We’ve of course covered many angle grinder hacks, such as this fixture for perfect cuts (something notoriously difficult to do with a handheld grinder), but this is the first time we’ve seen an angle grinder fly out of more than frustration. Do you have your own angle grinder hack to spin our way? Be sure to let the Tip Line know!
[JSK-koubou] is no stranger to making tools to improve their work, and this latest video is yet another in a long list of such builds, just checkout their YT channel to see the many other examples. The tool being highlighted this time is a semi-automatic grinder (Video, embedded below) which could be very handy in many situations.
Many of us struggle a little to get straight cuts with an angle grinder, especially with softer materials, as it is sometimes hard to get a good ‘feel’ of how the cut is proceeding. Once the cut is started, thin blades will tend to ‘track’ in the slot, so if it starts off a little bit, the whole cut will be off. Most annoying. Anything to help keep things straight and square would help a lot, with the extra feature of a motorized drive enabling a constant cut rate, and presumably giving an increase in the cut quality.
Since operation is hands-off, you could set it up, and leave it to do its thing, whilst you step aside, away from flying sparks, noise and the remote possibility of getting a splintered blade in your face, should the unthinkable happen. All good things.
The detailed build video shows what looks like a pretty solid construction, there are plans available on the accompanying website, but they do request a small donation of ¥1000 (less than $10 USD) to download them. Given the usefulness of the tool, this seems like a small price to pay. We quite liked some sections of the build video, where the tool is used to cut its own components, as it is built-up sequentially. Clever stuff! Another interesting technique to see was the use of a flame-heated (Stanley) knife blade as a drive belt end-jointer. Somewhat tough on the blade, but it’s a consumable item and gets the job done, so that’s good enough for us!
Parts wise, there’s nothing special at all here, with most easily sourced via the usual mechanical suppliers, but we reckon you’d be able to find most of it on eBay as well. We think this is exactly the sort of build that would work well in your local Makerspace, so perhaps give that a thought?
Bored with manually cutting off? Need an overkill solution for a mundane job? How about an Automatic Cut-Off Saw? If you need some defense against the mighty angle grinder, then perhaps Proteus is just the ticket?
How cool would it be if there was a material that couldn’t be cut or drilled into? You could make the baddest bike lock, the toughest-toed work boots, or the most secure door. Really, the list of possibilities just goes on and on.
The material is made of aluminium foam that’s embedded with a bunch of small ceramic spheres. It works by inducing retaliatory vibrations into the cutting tools, which turns the tools’ force back on themselves and quickly dulls their edges.
The creators have named the material Proteus after the elusive and shape-shifting prophet of Greek mythology who would only share his visions of the future with those who could get their arms around him and keep him still. It sounds like this material could give Proteus a run for his money.
The ceramic spheres themselves aren’t indestructible, but they’re not supposed to be. Abrading the spheres only makes Proteus stronger. As the cutting tool contacts them, they’re crushed into dust that fills the voids in the aluminium foam, strengthening the material’s destructive vibratory effect. The physical inspiration for Proteus comes from protective hierarchical structures in nature, like the impact-resistant rind of grapefruit and the tendency of abalone shells to resist fracture under the impact of shark teeth.
How It’s Made
At this point, Proteus is a proof of concept. Adjustments would likely have to be made before it can be produced at any type of scale. Even so, the recipe seems pretty straightforward. First, an aluminium alloy powder is mixed with a foaming agent. Then the mixture is cold compacted in a compressor and extruded in dense rods. The rods are cut down to size and then arranged along with the ceramic spheres in a layered grid, like a metallurgical lasagna.
The grid is spot-welded into a steel box and then put into a furnace for 15-20 minutes. Inside the furnace, the foaming agent releases hydrogen gas, which introduces voids into the aluminium foam and gives it a cellular structure.
According to their paper, the researchers tried to penetrate the material with an angle grinder, a water jet cutter, and a drill. Of these, the drill has the best chance of getting through because the small point of contact can find gaps more easily, so it’s less likely to hit a ceramic sphere. The researchers also made cylindrical samples without steel cladding which they used to test the compressive strength and prove Proteus’ utility as a structural material for beams and columns. It didn’t fare well initially, but became less compressible as the foam matrix collapsed.
The creation process lends some leeway for customization, because the porosity of the aluminium foam can be varied by changing the bake time. As for the drill bit problem, tightening up security is as easy as adjusting the size and/or density of the ceramic spheres.
In the video after the break, you can watch a chunk of Proteus eat up an angle grinder disc in under a minute. Some may argue about the tool wielder’s technique, but we think there’s something to be said for any material that can destroy a cutting disc that fast. They don’t claim that Proteus is completely impenetrable, but it does look impressive. We wish they would have tried more cutting tools like a gas torch, or experimented with other destructive techniques, like plastic explosives, but we suppose that research budgets only go so far.
For poor [workshop from scratch], winter brings the joy of a cold workshop. Since the building is structurally made from tin, warming up the room is difficult.
Naturally, the solution was to construct a homemade wood furnace. The build starts off with an angle grinder being taken to a compressed air tank. After sawing off the top and sanding down the edges, the builder slices out an opening and welds together some rods into a stand for the center. He then proceeds to weld some external frames for the furnace, as well as a chimney stack, some nifty covers joined by hinges, and a fan/temperature regulator to keep the fire going.
Most of the pieces seem to come from scrap metal lying around the workshop, although the degree to which the entire project comes together is quite smooth. Some filter and spray paint do the trick for cleaning up the furnace and making it look less scrappy. The last step? A stack of wooden logs and a blow torch to start the fun. Outside of the furnace, an LCD screen keeps track of the temperature, giving some feedback and control.
The result is perhaps a too effective at warming up the workshop, but the problem sure is solved!
Angle grinders are among the most useful tools for anyone who’s ever had to cut metal. They’re ergonomic, compact, and get the job done. Unfortunately, one of the tradeoffs you usually make when using them is precision.
But thankfully, there’s a DIY solution. YouTuber [workshop from scratch] demonstrated the build process for a sliding angle grinder in a recent video, welding steel beams into a flat frame and attaching fitted beams on top to slide across the rows. Where necessary, spacers are used to ensure that the slider is perfectly fitted to the beam. The contraption holding the angle grinder – a welded piece of steel bolted to the sliding mechanism – has a grip for the user to seamlessly slide the tool across the table.
The operation is like a more versatile and robust chop saw, not to mention the customized angle references you can make to cut virtually anything you like. The build video shows the entire process, from drill pressing and turning holes to welding pieces of the frame together to artfully spray painting the surface a classy black, with familiarity enough to make the project look like a piece of cake.
As the name implies, [workshop from scratch] is all about building your own shop tools, and we’ve previously taken a look at their impressive hydraulic vise and mobile crane builds. These tools, largely hacked together from scraps, prove that setting up your own shop doesn’t necessarily mean you need to break the bank.
In the video after the break, he takes an array of scrap metal including what appears to be a chunk of racking from the Home Depot and a rusted plate that looks like it could be peeled off the hull of a sunken ship, and turns it into a monsterous vise with five tons of clamping force. Outside of a handful of bolts, a couple of gas struts, and the hydraulic bottle jack that that provides the muscle, everything is hand-cut and welded together. No fancy machining here; if you’ve got an angle grinder, a welder, and of course the aforementioned stock of scrap metal, you’ve got the makings of your own mega vise.
The piece of racking is cut down the center to form the base of the vise, but most everything else is formed from individual shapes cut out of the plate and welded together. Considering the piecemeal construction methods, the final result looks very professional. The trick is to grind all the surfaces, including the welds, down until everything looks consistent. Then follow that with a coat of primer and then your finish color.
While the whole build is very impressive, our favorite part has to be the hand-cut cross hatching on the jaws. With the workpiece in one hand and angle grinder in the other, he cuts the pattern out with an accuracy that almost looks mechanical. If we didn’t know better, we might think [WorkshopFromScratch] was some kind of metalworking android from the future.
If there’s a small power tool as hackable as the angle grinder, we haven’t found it yet. These versatile tools put a lot of power in the palm of your hand, and even unhacked they have a huge range of functionality, from cutting to grinding to polishing and cleaning, just by choice of what goes on the arbor.
With a simple homebrew attachment, [Darek] turned his angle grinder into a micro-belt sander that’s great for those hard-to-reach places. The attachment that clamps where the disc guard normally lives adds a drive roller to the grinder’s arbor; idler rollers ride on the end of a small pneumatic spring that keeps the belt under tension. The belts themselves are cut down from wider sanding belts, and the attachment can take belts of various widths. And best of all, he did it all without any fancy machine tools. No lathe? No problem – the drive roller was ground to the proper crowned profile needed to keep belts centered using the angle grinder itself. The only problem we see is that the attachment can’t be easily removed from the grinder, but that’s OK. Grinders are like potato chips, after all – you can’t stop at one.