Betta Aims To Bring Wire EDM To The Desktop

Just as practical nuclear fusion has been “only 20 years away” for the last 80 years or so, the promise of electrical discharge machining (EDM) in the home shop seems to always be just around the corner. It’s hard to understand why this is so — EDM is electrically and mechanically more complicated than traditional subtractive manufacturing techniques, so a plug-and-play EDM setup seems always just out of reach.

Or perhaps not, if this 3D printed 4-axis wire EDM machine catches on. It comes to us from [John] at Rack Robotics and is built around the Powercore EDM power supply that we’ve previously featured. Since wire EDM is a process that requires the workpiece to be completely immersed in a dielectric solution, the machine, dubbed “Betta,” is designed to fit inside a 10-gallon aquarium — get it?

A lot of thought went into keeping costs down. for example, rather than use expensive sealed motors, [John] engineered the double CoreXY platform to keep the motors out of the water bath using long drive shafts and sealed bearings. The wire handling mechanism is also quite simple, at least compared to commercial WEDM machines, and uses standard brass EDM wire. The video below shows the machine going to town of everything from aluminum to steel, with fantastic results on thin or thick stock.

While Rack Robotics is going to be offering complete kits, they’re also planning on open-sourcing all the build files. We’re eager to see where this leads, and if people will latch onto EDM with the same gusto they did with 3D printing.

35 thoughts on “Betta Aims To Bring Wire EDM To The Desktop

  1. Don’t really know much about manufacturing so its the first I’ve heard of wire EDM. Seems pretty cool.

    As I grow older and my projects start getting more complex, I am realising that a “good” design is one which can be manufactured with the most ease. Manufacturing techniques are very interesting!

  2. Some electrical info on the necessary power supply for EDM from a project I did years ago:

    I never got that one finished–i got stuck on the mechanical side. The entire workspace need to be not just wet but /flowing/ in order to properly flush chips and prevent bridging between the tool and the workpiece, which (combined with the primitive state of rep raps at the time) was a substantial barrier for me. So I’m most excited about the mechanical parts of this project! If those can be solved, there’s a lot of fun you can have on the drive electronics side, and these days those electronics once perfected can be easily mass produced for cheap. Ah the march of progress.

    1. There’s a better way. Find a project she wants and point out how much cheaper you can do it if you had a wire EDM machine. You’re doing her a favour by buying one and the first project is for her.

      The first thing I printed on my 3d printer was a love symbol to my wife. Nothing fancy, but believe it or not she keeps it in a safe place because of what it means to her.

  3. Two thousand US Dollars for a preorder. Plus another 400 for the power supply?

    Dare I say that’s a bit steep? I could sell the wife on it if they kept to the high-three-figures…

      1. I worked on an Agie wire edm about 30 odd years ago, the part was not submerged, only a gentle flow of dialectric down the wire to flush debris and cool, too much flushing pressure could influence the wire. The wire had weights to tension, brass wire for roughing and stainless wire for finish with greater weight. It ran from punched tape. Good luck with your project. the only drawback to wire edm may be the wire, I used tons of it, although you could weigh in the brass.

    1. “I could sell the wife”

      I don’t think that would be legal,
      If it is, we’d probably want to see some photos before bidding.

    2. It’s early days. This is pretty dang cheap for advanced metalworking tools. It’s only due to the miracle of EDM that the frame alone doesn’t weigh 2000 pounds, which would cost more than this just for the shipping.

      Give it some time. Also economy of scale hasn’t kicked in yet; fairly quickly the Shenzhen factories will copy it.

  4. I ordered a portable EDM when I worked at a factory for about $4k in yr 2000 dollars. It only had an active Z axis and was designed for burning out broken taps and bolts. The work didn’t have to be immersed though. The flush fluid was pumped through the hollow carbon electrode and you’d recover it whatever way you could. Actually used it to burn out broken taps overhead several times.

  5. 6:10 in the video – that gear isn’t even close to correct, but I assume that’s because he didn’t take the time to setup the cut correctly.

    The machine overall is a huge step forward from previous attempts. I’ll definitely be following this.

  6. Would be great to have it at 48v rather than 65v. That would make it far easier to get into small labs and schools. 65v unfortunately trips the HSE brigade into overdrive

  7. The idea for building Iter has been conceived in the ’80-ies or ’90-ies, and back then it was already clear it would be ready to do it’s thing somewhere between 2025 and 2035. Iter was also never meant to be practical for energy delivery. Iter is “only” for research and figuring out how such a thing works. After Iter comes Demo. Demo is also not intended for practical / cheap nuclear fusion. Demo is meant as a demonstration that it’s possible to create a nuclear fusion reactor that economically viable. After Demo it’s expected more practical fusion plants can be built somewhere in the 2050-ies. And this timeline has been established over 30 years ago. Nuclear fusion has never been a short time goal. If you’ve been listening to the “practical fusion in 20 years” then you really have been listening to the wrong people, so please finally stop parroting that nonsense.

    Because of this ridiculous opening statement, my motivation for reading anything about EDM plummeted to below 0.

  8. Really, really awesome work, but it is limited to laser-cutter style through-cutting, even though it can ofcourse do so at a considerable angle. If you want to fabricate something like a compound gear, or any other stepped part this won’t, excuse the pun, cut it. Might “Morlock” here be working on any way to make this more like a typical 3-axis mill, sinker EDM perhaps?

    1. Their first release, alongside the Powercore v1 power supply, was a sinker build on an ender 3 frame. My understanding is that it may be returning in a future release, but you could always build the original edm setup with the new power supply, unless I’m mistaken. It’s like $500-600 between the power supply, the ender 3, and other parts.

  9. I like the initiative by the creator of this project, however i have a huge problem with the writer of the article. If you dont mind older machines which HAD Hates with a passion. I mean stuff with serial ports on them (HAD writers seem to think if it is not made in the past 5 minutes it is garbage) you can get these machines for pennies on the dollar. I picked up an older wire EDM form a local shop getting rid of it and they threw in a sinker. Both in working condition and the iron on them is great and for all practical purposes blows this project out of the water for $500. Again i like this project but people need to look at reality if you dont mind drip feeding code you can get freaking amazing machines for very little.

    1. Not saying you’re wrong – old machines are often great and far better than anything you could make or buy – but with a lot of old industrial machines they’re either too big for the home or need 3-phase power, or are just stuffed full of really arcane closed-source controls with no documentation.

      I can buy a used Bridgeport mill for pennies on the pound but if I want something that fits in my garage and runs on my household mains supply I’m paying 2-3x that for a small hobby machine that doesn’t require a forklift to move or a reinforced floor to stand on.

      That said – using the bones of an old machine and modifying or upgrading is a very overlooked approach, and the hobby community seem to be intent on making wobbly things out of 2020 extrusion and totally ignoring the reasons industrial machines use huge heavy castings.

      1. > the hobby community seem to be intent on making wobbly things out of 2020 extrusion and totally ignoring the reasons industrial machines use huge heavy castings.

        At least around here I expect that is simply being practical rather than ignoring the benefits. As AL extrusion are light, and you can always flatpack the thing you built. Where the huge heavy castings are heavy and huge, so terrible for anybody that doesn’t have a very settled job and a home they actually own with a large accessible space to put these huge machines. Once you have such a machine and you are suddenly kicked out of ‘your’ house or the very fluid job market pushes you to move somewhere else what do you do with a huge machine? And that lack of certainty does seem to be approaching fact of life for folks under 40 at least across much of Europe.

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