Fail Of The Week: Supercapacitor Spot Welder

[Julian] needed to weld a bit of nickel to some steel and decided to use a spot welding technique. Of course he didn’t have a spot welder sitting around. Since these are fairly simple machines so [Julian] set out to build a spot welder using a charged supercapacitor. The fundamentals all seem to be there — the supercap is a 100 Farad unit and with a charge of 2.6V, that works out to over 300 joules — yet it simply doesn’t work.

The problem is in how the discharge energy is being directed. Just using the capacitor would cause the charge to flow out as a spark when you got near the point to discharge. To combat this, [Julian] put a microswitch between the capacitor and the copper point he expected to use as the welding tip. The microswitch, of course, is probably not the best for carrying a large surge of current, so we suspect that may be part of why he didn’t get great results.

The other thing we noticed is that he used a single point and used the workpiece as a ground return. Most spot welders use two points near each other or on each side of the workpiece. The current from the capacitor is probably just absorbed by the relatively large piece of metal.

The second video below from [American Tech] shows a 500F capacitor doing spot welding with little more than two wires and it seems to work. Hackaday’s own [Sean Boyce] even made one out of some whopping 3000F caps. It did work, although he’s been pursuing improvements.

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Russian EBike Goes Everywhere, Possibly Legal

Electric bikes may be taking the world by storm, but the world itself doesn’t have a single way of regulating ebikes’ use on public roads. Whether or not your ebike is legal to ride on the street or sidewalk where you live depends mostly on… where you live. If you’re lucky enough to live in a place where a bicycle is legally defined as having fewer than four wheels and capable of being powered by a human, though, this interesting bike from Russia might be the best homemade ebike we’ve ever seen. (Video embedded below the break.)

While some of the details of this build might be lost on those of us who do not know any Slavic languages, the video itself shows off the features of this electric vehicle build quite well. It has a custom built frame with two wheels up front, each with its own independent suspension, allowing it to traverse extremely rough terrain with ease even a mountain bike might not be able to achieve. It seems to be powered by a relatively simple rear hub in the single rear wheel, and can probably achieve speeds in the 20 km/h range while holding one passenger and possibly some cargo.

The impressive part of this build isn’t so much the electrification, but rather the suspension components. Anyone looking for an offroad vehicle may be able to take a bit of inspiration from this build. If you’re more interested in the drivetrain, there are plenty of other vehicles that use unique electric drivetrains to check out like this electric boat. And, if you happen to know Russian and see some other interesting details in this build that the native English speakers around here may have missed, leave them in the comments for us.

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Hydraulic Bench Vise A Masterpiece Of Scrap Metal And Angle Grinding

For most of us, a vise is the sort of thing you clamp onto the edge of a workbench and crank down by hand. It might even be made of plastic, depending on the kind of work you find yourself doing with it. But it’s safe to say that [WorkshopFromScratch] won’t be soldering any PCBs in the jaws of this nearly 100 lb hydraulic vise that he built from, well… scratch.

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.

Being able to work with metal is a fantastic skill to have, and we’re always impressed to see what folks can produce with a welder and some scrapyard finds. Especially when they build tools and equipment that can be put to practical use.

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Nanoparticles Make Mega Difference For “Unweldable” Aluminum

Though much of it is hidden from view, welding is a vital part of society. It’s the glue that holds together the framework of the cars we drive, the buildings we occupy, the appliances we use, and the heavy machinery that keeps us moving forward. Every year, the tireless search continues for stronger and lighter materials to streamline our journey into the future of transportation and space exploration.

Some of these futuristic materials have been around for decades, but the technology needed to weld them lagged behind. A group of researchers at UCLA’s Samueli School of Engineering recently found the key to unlocking the weldability of aluminium alloy 7075, which was developed in the 1940s. By adding titanium carbide nanoparticles to the mix, they were able to create a bond that proved to be stronger than the pieces themselves.

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This Beer Keg Is A Side Car

Bikes are a great way to get around. They’re cheap compared to cars and can be faster through city traffic, and you can get some exercise at the same time. The one downside to them is that the storage capacity is often extremely limited. Your choices are various bags strapped to the bike (or yourself), a trailer, or perhaps this bicycle side car made from a beer keg.

Sidecars are traditionally the realm of motorcycles, not bicycles, but this particular bike isn’t without a few tricks. It has an electric motor to help assist the rider when pedaling. With this platform [Laura Kampf] has a lot of potential. She got to work cutting the beer keg to act as the actual side car, making a hinged door to cover the opening. From there, she fabricated a custom mount for the side car that has a custom hinge, allowing the side car to stay on the road when the bike leans for corners.

For those unfamiliar, [Laura] is a master welder with a shop located in Germany. We’ve seen some of her work here before, and she also just released a video showing off all of her projects for the last year. If you’re an aspiring welder, or just like watching a master show off her craft, be sure to check those out or go straight to the video below.

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Plastics: Acrylic

If anything ends up on the beds of hobbyist-grade laser cutters more often than birch plywood, it’s probably sheets of acrylic. There’s something strangely satisfying about watching a laser beam trace over a sheet of the crystal-clear stuff, vaporizing a hairs-breadth line while it goes, and (hopefully) leaving a flame-polished cut in its wake.

Acrylic, more properly known as poly(methyl methacrylate) or PMMA, is a wonder material that helped win a war before being developed for peacetime use. It has some interesting chemistry and properties that position it well for use in the home shop as everything from simple enclosures to laser-cut parts like gears and sprockets.

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Welding Robot Takes On A Hot, Dirty, Dangerous Job

They used to say that robots would take over the jobs too dirty or dangerous for humans. That is exactly what [Joel Sullivan] had in mind when he created this welding robot. [Joel] designed the robot for the OSB industry. No, that’s not a new operating system, it’s short for Oriented Strand Board. An engineered lumber, OSB is made of strands (or chips) of wood. It’s similar to plywood but doesn’t require large thin sheets of lumber. To make a panel of OSB, a 5-inch thick matt of wood chips is mixed with glue and compressed down to 5/16″ at 7500 PSI and 400° F.

The presses used to make OSB are a massively parallel operation. 20 or more boards can be pressed at once. Thy press is also a prime area for damage. A nut or bolt hidden in the wood will dig into the press, causing a dent which will show up on every sheet which passes through that section. The only way to fix the press is to shut it down, partially dismantle it, and fill the void in with a welder. [Joel’s] robot eliminates most of the downtime by performing the welding on a still hot, still assembled press.

The robot looks like it was inspired by BattleBots, which is fitting as the environment it works in is more like a battleground. It’s a low, wide machine. In the front are two articulated arms, one with a welder, and one with a die grinder. The welder fills any voids in the press platen, and the die grinder grinds the fresh welds flat.  An intel NUC controls things, with plenty of motor drives, power supplies, and relays on board.

[Joel’s] bot is tethered, with umbilicals for argon, electricity and compressed air. Air travels through channels throughout the chassis and keeps the robot cool on the hot press. Everything is designed for high temperatures, even the wheels. [Joel] tried several types of rubber, but eventually settled on solid aluminum wheels. The ‘bot doesn’t move very fast, so there is plenty of traction. Some tiny stepper motors drive the wheels. When it’s time to weld, pneumatic outriggers lock the robot in place inside the narrow press.

Cameras with digital crosshairs allow the operator to control everything through a web interface. Once all the parameters are set up, the operator clicks go and sparks fly as the robot begins welding.

If you’re into seriously strong robots, check out trackbot, or this remote-controlled snow blower!

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