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30 Articles

Powercore Aims To Bring The Power Of EDM To Any 3D Printer

March 7, 2023 by 39 Comments

The desktop manufacturing revolution has been incredible, unleashing powerful technologies that once were strictly confined to industrial and institutional users. If you doubt that, just look at 3D printing; with a sub-$200 investment, you can start making parts that have never existed before.

Sadly, though, most of this revolution has been geared toward making stuff from one or another type of plastic. Wouldn’t it be great if you could quickly whip up an aluminum part as easily and as cheaply as you can print something in PLA? That day might be at hand thanks to Powercore, a Kickstarter project that aims to bring the power of electric discharge machining (EDM) to the home gamer. The principle of EDM is simple — electric arcs can easily erode metal from a workpiece. EDM machines put that fact to work by putting a tool under CNC control and moving a precisely controlled electric arc around a workpiece to machine complex shapes quickly and cleanly.

Compared to traditional subtractive manufacturing, EDM is a very gentle affair. That’s what makes EDM attractive to the home lab; where the typical metal-capable CNC mill requires huge castings to provide the stiffness needed to contain cutting forces, EDM can use light-duty structures and still turn out precision parts. In fact, Powercore is designed to replace the extruder of a bog-standard 3D printer, and consists almost entirely of parts printed on the very same machine. The video below shows a lot of detail on Powercore, including the very interesting approach to keeping costs down by creating power resistors from PCBs.

While we tend to shy away from flogging crowdfunded projects, this one really seems like it might make a difference to desktop manufacturing and be a real boon to the home lab. It’s also worth noting that this project has roots in the Hackaday community, being based as it is on [Dominik Meffert]’s sinker EDM machine.

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Building A Plasma Piano Ain’t Easy

February 8, 2023 by 17 Comments

Electronic arcs can be made to “sing” if you simply modulate them on and off at audible frequencies. We’ve seen it done with single Tesla coils, and even small Tesla choirs, but [Mattias Krantz] took this to extremes by building an entire “plasma piano” using this very technique.

The build relies on ten transformers more typically used in cathode ray tubes. The transformers are capable of generating high enough voltages to create arcs in the air. The transformers are controlled by an Arduino, which modulates the arcs at musical frequencies corresponding to the keys pressed on the piano. Sensing the keys of the piano is achieved with a QRS optical sensor strip designed for performance capture from conventional pianos. For the peak aesthetic, the transformer outputs are connected to the metal hammers of the piano, and the arcs ground out on a metal plate in the back of the piano’s body. This lets arcs fly across the piano’s whole width as its played. Ten transformers are used to enable polyphony, so the piano to play multiple tones at once.

Building the piano was no mean feat for [Mattias], who admitted to having very limited experience with electronics before beginning the build. However, he persevered and got it working, while thankfully avoiding injury from high voltage in the process. This wasn’t easy, as Arduinos would regularly freeze from the noise produced by the arcs and the system would lose all control. However, with some smart software tweaks to the arc control and some insulating panels, [Mattias] was able to get the piano playable quite well with a beautiful chiptune tone.

It bears stating that HV work can be dangerous, and you shouldn’t try it at home without the proper understanding of how to do so safely. If you’re confident though, we’ve featured some great projects in this space before. Video after the break.

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Flat Transformer Gives This PCB Tesla Coil Some Kick

June 9, 2021 by 16 Comments

Arguably, the most tedious part of any Tesla coil build is winding the transformer. Getting that fine wire wound onto a suitable form, making everything neat, and making sure it’s electrically and mechanically sound can be tricky, and it’s a make-or-break proposition, both in terms of the function and the aesthetics of the final product. So this high-output printed circuit Tesla should take away some of that tedium and uncertainty.

Now, PCB coils are nothing new — we’ve seen plenty of examples used for everything from motors to speakers. We’ve even seen a few PCB Tesla coils, but as [Ray Ring] points out, these have mostly been lower-output coils that fail to bring the heat, as it were. His printed coil generates some pretty serious streamers — a foot long (30 cm) in some cases. The secondary of the coil has 6-mil traces spaced 6 mils apart, for a total of 240 turns. The primary is a single 240-mil trace on the other side of the board, and the whole thing is potted in a clear, two-part epoxy resin to prevent arcing. Driven by the non-resonant half-bridge driver living on the PCB below it, the coil can really pack a punch. A complete schematic and build info can be found in the link above, while the video below shows off just what it can do.

Honestly, for the amount of work the PCB coil saves, we’re tempted to give this a try. It might not have the classic good looks of a hand-wound coil, but it certainly gets the job done. Continue reading “Flat Transformer Gives This PCB Tesla Coil Some Kick” →

Homemade EDM Machine Moves From Prototype To Production

April 30, 2021 by 40 Comments

Of all the methods of making big pieces of metal into smaller pieces of metal, perhaps none is more interesting than electrical discharge machining. EDM is also notoriously fussy, what with having to control an arc discharge while precisely positioning the tool relative to the workpiece. Still, some home gamers give it a whirl, and we love to share their successes, like this work-in-progress EDM machine. (Video, embedded below.)

We’ve linked [Andy]’s first videos below the break, and we’d expect there will be a few more before all is said and done. But really, for being fairly early in the project, [Andy] has made a lot of progress. EDM is basically using an electric arc to remove material from a workpiece, but as anyone who has unintentionally performed EDM on, say, a screwdriver by shorting it across the terminals in a live outlet box, the process needs to be controlled to be useful.

Part 1 shows the start of the build using an old tap burning machine, a 60-volt power supply, and a simple pulse generator. This was enough to experiment with the basics of both the mechanical control of electrode positioning, and the electrical aspects of getting a sustained, useful discharge. Part 2 continues with refinements that led very quickly to the first useful parts, machined quickly and cleanly from thin stock using a custom tool. We’ll admit to being impressed — many EDM builds either never get to the point of making simple holes, or stop when progressing beyond that initial success proves daunting. Of course, when [Andy] drops the fact that he made the buttons for the control panel on his homemade injection molding machine, one gets the feeling that anything is possible.

We’re looking forward to more on this build. We’ve seen a few EDM builds before, but none with this much potential.

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Fuel From Water Using Only An Arc Welder

April 26, 2020 by 36 Comments

Water, high currents, blinding balls of plasma, and a highly flammable gas that’s toxic enough to kill you in three minutes if you breathe enough of it. What’s not to love about this plasma-powered water gas generator?

In all seriousness, [NightHawkInLight] is playing with some dangerous stuff here, and he’s quite adamant about this one being firmly in the “Don’t try this at home” category. But it’s also fascinating stuff, since it uses nothing but a tank of water and an electric arc to produce useful amounts of fuel very quickly. It’s easy to jump to the conclusion that he’s talking about the electrolytic splitting of water into the hydrogen-oxygen mix HHO, but this is something else entirely.

Using a carbon electrode torch connected to his arc welder, a setup that’s similar to the one he used to make synthetic rubies, [NightHawkInLight] is able to strike an underwater arc inside a vessel that looks for all the world like a double-barreled bong. The plasma creates a mixture of carbon monoxide and hydrogen which accumulates very rapidly in the gasometer he built to collect the flammable products produced by a wood gasifier.

The water gas burns remarkably cleanly, but probably has limited practical uses. Unless you live somewhere where electricity costs practically nothing, it’ll be hard to break even on this. Still, it’s an interesting look at what’s possible when plasma and water mix.

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Mr. Carlson Gets Zapped By Snow

January 25, 2020 by 47 Comments

As a Canadian, [Mr. Carlson] knows a thing or two about extreme winter weather. Chances are good, though, that he never thought he’d get zapped with high voltage generated by falling snow.

[Mr. Carlson]’s shocking tale began with a quiet evening in his jam-packed lab as a snowstorm raged outside. He heard a rhythmic clicking coming from the speakers of his computer, even with the power off. Other speakers in the lab were getting into the act, as was an old radio receiver he had on the bench. The radio, which was connected to an outdoor antenna by a piece of coax, was arcing from a coil to the chassis in the front end of the radio. The voltage was enough to create arcs a couple of millimeters long and bright blue-white, with enough current to give [Mr. Carlson] a good bite when he touched the coax. The discharges were also sufficient to destroy an LED light bulb in a lamp that was powered off but whose power cord was unlucky enough to cross the antenna feedline.

Strangely, the coil from which the arc sprang formed a 36-ohm shunt to the radio’s chassis, giving the current an apparently easy path to ground. But it somehow found a way around that, and still managed to do no damage to the sturdy old radio in the process. [Mr. Carlson] doesn’t offer much speculation as to the cause of the phenomenon, but the triboelectric effect seems a likely suspect. Whatever it is, he has set a trap for it, to capture better footage and take measurements should it happen again. And since it’s the Great White North, chances are good we’ll see a follow-up sometime soon.

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Improbably Cheap Pocket Welder Gets An ESP32 Makeover

November 4, 2019 by 25 Comments

If you move in certain shady circles, you may have noticed the crop of improbably cheap “pocket welders” popping up on the market these days. They’re all variations on a theme, most with wildly optimistic specs minimal accessories of the lowest possible quality. But their tiny size and matching price make them irresistible to the would-be welder, as well as attractive to hardware hackers.

With a 220-V outlet in the garage waiting to be filled and well-knowing the risks, [Mr. RC-Cam] purchased one of these diminutive welding machines. Its shortcomings were immediately apparent, and a complete rework of the welder was undertaken. After addressing safety issues like the lack of a ground connection, [Mr. RC-Cam] added a color-matched 3D-printed hood to house a fancy new LCD touchscreen display. Backing that up is an ESP32 with Bluetooth, which supports remote control via a key fob. He also added a current sense board that uses the welder’s current shunt to measure welding current. Expediently calibrated using a waffle iron and a milli-ohmmeter, the sensor showed that the 200A max advertised for the welder was more like 100A. He tried adding some big electrolytics to fix the current issues, but no dice. With a decent stinger and ground clamp, the modified welder is good enough for his needs, and much was learned in the process. We call that a hacking win.

As an aside, [This Old Tony] recently did a review on a similar welder if you want more details on the internals. We also covered the conversion of a buzz-box to a TIG welder recently, should that be more your style.

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