The March Toward A DIY Metal 3D Printer

[Hyna] has spent seven years working with electron microscopes and five years with 3D printers. Now the goal is to combine expertise from both realms into a metal 3D printer based on electron-beam melting (EBM). The concept is something of an all-in-one device that combines traits of an electron beam welder, an FDM 3D printer, and an electron microscope. While under high vacuum, an electron beam will be used to fuse metal (either a wire or a powder) to build up objects layer by layer. That end goal is still in the future, but [Hyna] has made significant progress on the vacuum chamber and the high voltage system.

The device is built around a structure made of 80/20 extruded aluminum framing. The main platform showcases an electron gun, encased within a glass jar that is further encased within a metal mesh to prevent the glass from spreading too far in the event of an implosion.

The design of the home-brewed high-voltage power supply involves an isolation transformer (designed to 60kV), using a half-bridge topology to prevent high leakage inductance. The transformer is connected to a buck converter for filament heating and a step up. The mains of the system are also connected to a voltage converter, which can be current-fed or voltage-fed to operate as either an electron beam welder or scanning electron microscope (SEM). During operation, the power supply connects to a 24V input and delivers the beam through a Wehnelt cylinder, an electrode opposite an anode that focuses and controls the electron beam. The entire system is currently being driven by an FPGA and STM32.

The vacuum enclosure itself is quite far along. [Hyna] milled a board with two outputs for a solid state relay (SSR) to a 230V pre-vacuum pump and a 230V pre-vacuum pump valve, two outputs for vent valves, and inputs from a Piranni gauge and a Cold Cathode Gauge, as well as a port for a TMP controller. After demoing the project at Maker Faire Prague, [Hyna] went back and milled a mold for a silicone gasket, a better vacuum seal for the electron beam.

While we’ve heard a lot about different metal 3D printing methods, this is the first time we’ve seen an EBM project outside of industry. And this may be the first to attempt to combine three separate uses for an HV electron beam into the same build.

20 thoughts on “The March Toward A DIY Metal 3D Printer

      1. Mods deleted. Mine’s gone as well. No biggie, project is still cool even though we’re not going to be making anything significant for awhile. More proof of concept and hopefully safety.

  1. Not sure what side of the camp you’re on, but as I see it, here is the issue – Once you restrict knowledge, any knowledge, you’re on a dangerous path. People with CNC’s have been able to create items from ‘certain CAD plans’ for DECADES. There have been more books published on the subject than you can count. Even modelling up your own and machining is a daily occurrence. Being able to 3D print said CAD plans is in many ways significantly harder than to machine the object on a CNC or mill/lathe since it will STILL require post processing for good functionality.
    In reality, you dont even need fancy equipment to create objects. Just a little research and effort will yield you results.
    I believe that all knowledge should always be free or else setting the precedent for criminalizing or preventing one drawing or plan will inevitably lead to other things that ‘someone’ other than you labels as dangerous and so on and so forth.
    Plenty of the projects here on Hackaday could easily be seen as totally dangerous – including this piece, so where would the information restriction stop once the censorship ball starts rolling?

    1. ^100% agree

      I also believe that the number of illegal & ghost guns already on the street is the real problem, but instead we have people fear mongering about the fact that someone COULD make something dangerous.

      1. ” As the Americans learned so painfully in Earth’s final century, free flow of information is the only safeguard against tyranny. The once-chained people whose leaders at last lose their grip on information flow will soon burst with freedom and vitality, but the free nation gradually constricting its grip on public discourse has begun its rapid slide into despotism. Beware of he who would deny you access to information, for in his heart he dreams himself your master.

        Commissioner Pravin Lal
        ‘U.N. Declaration of Rights’ ”

        Is the exact quote.

        http://www.generationterrorists.com/quotes/smac.html

    2. Agreed 1000%. I run a CNC EDM, and CNC die mills, and standard manual machinery. Anyone who knows how to shape the world around them can make a dangerous item of any kind quite trivially. Its all just knowledge, knowledge is power.

      Now Im also a blacksmith, and if theres anyone you should honestly seriously fear, its a blacksmith. No other skill allows someone to take a broken axel on the side of the road, or any other small lump of any steel, and forge it into a sword. Or a shovel. In fact, start with axel, forge to shovel, then forge the shovel into a working AK-47.

      Im not kidding, at all. Guy in Russia did it, it was on Hackaday previously.

      Blacksmiths are a tyrant’s nightmare. You can’t outlaw fire, hammers, and steel.

      This technology is more refined, buts its all the same-applied knowledge. Try outlawing thinking if you want to stop all danger. You still won’t succeed

  2. This project seems like it could be used in a von neumann probe. Is there a website for those interested in the subject? Even a limited non reproducing dumb remote controlled probe could have applications in asteroid mining, or off planet solar cells.

  3. One of the immutable rules of hacking, anything that has to be built in a vacuum inside an olde timey bell jar inside of a wire cage is automatically an extra 10 cool points.

  4. Everything about this project just screams amazing at me. Really impressive! I would pay to sit down with the creator and just ask questions about it for hours.

    Really inspiring to see someone setting out at work on something this technical and ambitious with a solid skillset

  5. There’s an opportunity to make this into a universal metal recycler, by combining subtractive and additive manufacturing into a single machine. If an electro-discharge machine were added as a tool option, its swarf is fine metal powder, feedstock for e-beam. The venn diagram of materials that can be processed by EDM, EBM, and the electron microscope, is just one big circle, anything electrically conductive. Insert a scrap of metal, let EDM spark it off, settle out the swarf, drain the dielectric and run the vacuum, then e-beam the swarf back onto it, in some new configuration.

    Ben Fleming’s got a book on how to DIY an EDM, and it’s pretty good, except you’ll need to find replacements for all his RadioShack parts.

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