Make Your Own Plasma Cutter

Of all the tools that exist, there aren’t many more futuristic than the plasma cutter, if a modern Star Wars cosplay if your idea of futuristic. That being said, plasma cutters are a powerful tool capable of making neat cuts through practically any material, and there are certainly worst ways to play with high voltage.

Lucky enough, [Plasanator] posted their tutorial for how to make a plasma cutter, showing the steps through which they gathered parts from “old microwaves, stoves, water heaters, air conditioners, car parts, and more” in the hopes of creating a low-budget plasma cutter better than any on YouTube or from a commercial vendor.

The plasma cutter does end up working up quite an arc, with the strength to slice through quarter-inch steel “like a hot knife through butter”.

Its parts list and schematic divide the systems into power control, high current DC, low voltage DC, and high voltage arc start:

  • The power control contains the step down transformer and contactor (allows the DC components to come on line)
  • The high current DC contains the bridge rectifier, large capacitors, and reed switch (used as a current sensor to allow the high voltage arc to fire right when the current starts to travel to the head, shutting down the high voltage arc system when it’s no longer necessary)
  • The low voltage DC contains the power switch, auto relays, 12V transformer, 120V terminal blocks, and a terminal strip
  • The high voltage arc start contains the microwave capacitor and a car ignition coil

At the cutting end, 13A is used to cut through quarter-inch steel. Considering the considerably high voltage cutter this is, a 20 A line breaker is needed for safety.

Once the project is in a more refined state, [Plasanator] plans on hiding components like the massive capacitors and transformer behind a metal or plastic enclosure, rather than have them exposed. This is mainly for safety reasons, although having the parts exposed is evocative of a steampunk aesthetic.

In several past designs, stove coils were used as current resistors and a Chevy control module as the high voltage arc start. The schematic may have become more refined with each build, but [Plasanator]’s desire to use whatever components were available certainly has not disappeared.

[Thanks to jafinch78 for the tip!]

31 thoughts on “Make Your Own Plasma Cutter

  1. That is pretty impressive. I guess the concept is quite simple I assumed not overloading the lower voltage was the complex part, start a high voltage spark, keep enough voltage and amps to melt metal, spray air through it. The low amperage is painfully slow to watch. Some commercial options just to have the higher amperage would be worth it. That propane tank is far from 1/4 inch steel… it might do it but he would be there all day.

    1. I guessed you missed the isolation transformer?

      Great project, and it demystifies the process of plasma cutting. It got me wondering whether anyone had tried to make a plasma cutter using a stick welder as the DC source… there were some Google hits but none seemed definitive, or were just discussing cutting with a stick welder (no air, no HV arc-starter). Anyone know of a decent plasma cutter that does start with a stick-welder?

      1. don’t get me wrong, I am totally into DIY; but here I don’t see the point. You can buy a cheap entry level plasma cutter for under $250 and it comes with hoses,cables,nozzle and accessories. Why bother making one yourself? The most interesting parts like the nozzle and pistol you have to buy off the shelf anyway.

        1. >> I am totally into DIY; but here I don’t see the point. … Why bother making one yourself?
          DiY is usually all about saving money. But hackers make things for all sorts of reasons. Saving money isn’t always the end game. In this case, the fellow states he likes to make tools and machinery; The reward is doing what you love.

          1. Agree, not a lot of cost/benefit unless everything but the torch/consumables/work clamp is on hand or free, but then there is the thrill of DIY. But my personal thrill factor goes down with any project of high current at anything over 12 volts…

        2. Also cheaper Lidl Parkside PPS 40 A1 plasma cutter cost less and its available cross the Europe. It’s working fine and its also safer
          but this plasma cutter diy concept is showing simplicity… for some locations such like India/Africa or Amazonia where is
          homemade plasma from junkyard only the solution. (price is priority safety minority :P and package from china is cost like plasma cutter)

        3. Some people like myself already have the vast majority of parts shown. Speaking for myself specifically, I’d need the ignition coil, auto relays and reed switch. Everything else, I’ve got – usually multiples of. I want a plasma cutter – and will be buying a plasma cutter in the future. But I can’t swing that today. I was considering picking up an ignition coil for other possible experiments, so this sounds like an interesting band-aid for the time being. And maybe upon building it, I’ll see some simple ways that I could upgrade it to become a potentially permanent solution. Because, ideally, I’d like to have 2 plasma cutters – one dedicated to a plasma table (CNC) and one in my welding cart for quick manual use. So even if the odds are slim that I’ll be able to build one capable of that kind of use, it still seems worth trying. Plus, I might learn something about plasma cutters that I otherwise wouldn’t have that might help me to maintain/repair one that I’ve purchased. So, there may not be a point for everybody, but to me it makes a good deal of sense.

        4. Because sometimes people need to put things together theirselves to fully grasp the concept of how it works and it’s components. And it’s better to make one from the ground up then to take one apart.

    1. Cannot agree more, as it comes with a box, not a ratsnet waiting to catch fire.
      I’m totally in the DIY too, but I favor project not available to consumer, so you can focus more, not trying to make a dremel or any other cheap tools.

    2. I just bought a Cut50 off a guy who got it on ebay… didn’t work out of the box and the vendor refused to replace or refund…So I basically paid him for the whip and the filter, to build my own…

  2. Interesting comments. Lately I’m seeing more feedback on HAD that insist that the project should/could have been store bought. But HAD is a place for sharing hacks. And reading about the project is the very reason I visit HAD.

    And we can be assured that these builders know they could have bought what they built and saved money and time. Thank goodness the don’t or HAD would be mostly black space framed with Google ads.

    Maybe there should be a HAD spinoff that reports on ready to use products instead. We could call it AAD (AmazonADay).

    1. I couldn’t agree more Thomas!

      I love making things for the sake of making things, I see it as my creative outlet.
      I think people are seeing these articles thinking “why should I do that”. HaD is not trying to tell you what projects you should undertake, and HaD is not saying that these are necessarily good ideas either.

    2. Agree fully. It’s not about the end product. Sometimes the learning process is what is enjoyable. The, not having to buy it part is relevant in many third world countries. It is relevant to people that may only need a portion of the build to improve something they are working on. Also, this is the classic, car, built it bought it vs. both have merits. Glad you have 200$ to throw at a machine. (Gonna just buy one) not everyone does(24yo me.)

      1. Totally true in general. But not for this particular project. The most important (and interesting) thing in/on/of a plasma cutter is the hose/cable/pistol assembly and the nozzle. If you buy that stuff and DIY the power supply; that is like buying an iPhone, build a USB-charger for it with off-the-shelf parts and call it “make your own iPhone”.
        Thats the point.

        1. You obviously understand very little about plasma cutting and or welding processes in general. Your analogy should be it’s like building the iPhone and charger and buying the usb cable. the handpiece just get the energy to the work, it’s most certainly not the most interesting part of things. All the work really happens in the power end of things (the part he built).

    3. I’ll add is nice to critique and have offered areas of opportunity for improvement also in cost effective ways and means as is noted an isolation transformer and other suggestions help make the cost effective system from salvaged and maybe even free parts safer and more effective.

      1. Wondering what the best tip and handle to use is? Seems I recall the cheapest effective bought plasma cutter reviews has one or more that recommend investing in a more common, with better quality consumables, plasma cutter torch. Last I left off on this project (besides looking into making an arc/ICP spectrometer source potential)… the torch was what I wanted to look back and see which review recommended a better torch.

  3. A lot of comments mentioning that it would be better to buy, since there are cheap units out there. Well — if you watch the video, you’ll note the date on it is 2014, and in the description the guy says he made the thing 5 years before that. 10 years ago, there weren’t a lot of cheap units on the market if any. Hackaday has just taken its time covering this build, is all.

  4. Why build this? Why build anything. Why build a ship in a bottle when you can purchase it already finished. Who needs a stove or oven to cook breakfast lunch and dinner when you can buy it already made? Who needs to build their own fence when they can hire someone else to do it for you. If you need to ask why build this DIY plasma cutter I need to ask why are you here reading about DIY? I won’t ever build this because I don’t need a plasma cutter and would probably buy one if I did. But I am as fascinated and awe struck by this as I was by a Forrest Mims DIY published in the 1980’s that used a Heath Kit laser to build an eavesdropping device (ethics notwithstanding) that bounced the laser off a window pane which was modulated by the sonic vibrations of the window created by conversations nearby. I didn’t build that either. Thanks Sharon Lin.

  5. Thanks for the good tutorial on making a plasma cutter! I think if one wants to make it then he/she has to invest too much money to build it. So it is very simple to buy rather than build.

    However, in some situations, you have to build your owns of premade machines are not helpful. I think it is useful in that situation.

  6. I would find it quite handy to integrate with my truck for onboard mobile plasma cutter. Which would be nice to work into the body of the vehicle as opposed to strapping a premade box one to it somewhere and figure how to get the power to it.

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