Metal 3D Printing Hack Chat

Printing isn't just for plastic

Wednesday, March 9, 2022 12:00 pm PST Local time zone:
Hack Chat
Similar projects worth following

Agustin Cruz will host the Hack Chat on Wednesday, March 9 at noon Pacific.

Time zones got you down? Try our handy time zone converter.


3D printing has been an enabling technology, and the ability to create parts that never existed anywhere before has been a real game-changer. But the cheap and readily accessible FDM and SLA printers we've come to depend on are not without their drawbacks, chief among which is that they only make plastic parts. Wouldn't it be great if we home-gamers had the ability to print metal parts just like they do in industry? Agustin Cruz thinks so, and he's been hard at work on an electron-beam sintering printer to make that dream come true. Dealing with the technical challenges of such a printer hasn't been easy, but then again, squeezing out melted plastic wasn't easy at first either.

Agustin has agreed to take a little time out of his project to talk to us about his progress, and to share what he has learned about electron-beam printing. Along the way, we'll talk about metal printing in general, and perhaps even take a look at where the whole field is going and how -- and when -- it'll penetrate the hobby printing market.

  • Hack Chat Transcript, Part 2

    Dan Maloney03/09/2022 at 21:06 0 comments

    Agustin Cruz12:35 PM
    Q: What type of electron gun is it out of interest, from what i understand there are different types, is it thermionic ?

    A: Yes, there are different types, shapes, filaments, for the electron gun. I´m going to detail this in the project page :)

    burdickjp12:35 PM
    Using the e-beam to keep the whole working volume at an elevated temperature is common practice in commercial e-beam powder bed systems.

    George Albercook12:36 PM
    @RichardCollins Do underestimate people. You ca roll your own oil diffusion pump.

    Thomas Shaddack12:36 PM
    For vacuum class feedthroughs, I heard about active brazes that can braze ceramics to metals (typically titanium is added for oxide ceramics, manganese(?) for graphite). For sealing of the minute cracks, silanols could be used to deposit silicate within in a sol-gel way.

    Agustin Cruz12:37 PM
    Q: Even with your baffle, oil contamination of the vacuum chamber is inevitable. Are you concerned that oil contamination will effect how smoothly the powder move? Can you heat the powder to drive off all of the oil?

    A: Good question George. As soon I get the 0.1mm diameter spot Im going to perform the sintering tests and report the results back to you

    George Albercook12:37 PM
    I think not needing an aneling oven is a small advantage compared to not needing a high powered laser.

    Thomas Shaddack12:37 PM
    Another thought. Thermal camera to watch the powder surface, and feedback to the beam control to deliver just enough energy.

    RichardCollins12:38 PM
    @Al Williams As I recall, one of the problems with a beam onto a complex metal object, is that when it accumulates charge the field calculations get complicated. And there are xrays when you start ramping up the power. Your current is limited by the electron source and that is a materials problem. If you use ions, they are heavier and have a much smaller wavelength for precision, and heavier more momentum and energy per particle. The mass spectrometer guys and accelerator guys have some pretty good methods.

    Agustin Cruz12:38 PM
    Q: If you don't have another source you can get high vacuum electrical feedthroughs from the magnetron tube in discarded microwave ovens. I have dozens of magnetron tubes that I have been saving for the feedthroughs if you want some

    A: Yes please!. I really appreciate it. We can talk later. Many thanks George for your help!

    George Albercook12:39 PM

    Agustin Cruz12:41 PM
    Q: Thought. Can the gun be defocused, resp. the beam spot area regulated? Then it could dramatically lower the time necessary for the rastering over the area. We need to deliver x joules to mm2, so a fat beam with higher current vs thin beam with lower current, switchable/adjustable during process, could give us both higher speed and high details... am I right?

    A: You can defocus the electron beam. This is an advantage over laser. You can control the power and the beam diameter. So, you can defocus to heat the powder, and then you can focus again to sintering the powder

    burdickjp12:41 PM
    @RichardCollins Oh, that's interesting. A big problem with e-beams is that the melt pool gives of gases that cause scattering, so the feature resolution is limited by this scattering.

    I'm thinking that wouldn't be as problematic for heavier particle beams.

    George Albercook12:42 PM
    I'm not an EE but along the lines of accessible technology, you can also get 6000VDC power supplies from old microwave ovens. The last stage is a voltage doubler maybe you could double is again. I don't know how smooth it is and if you can vary it. I know they are typically rated at 1000W of microwave power but I don't know if that means that the power supply puts out all of that, more or less.

    Guru-san12:42 PM
    What do you expect to be the biggest roadblocks and most expensive parts of the system from where you stand?

    Thomas Shaddack12:42 PM
    could the powder be locally preheated, drive out the gasses, and THEN melted?

    Agustin Cruz12:42 PM
    Q: (apologies if I missed the answer):...

    Read more »

  • Hack Chat Transcript, Part 1

    Dan Maloney03/09/2022 at 21:05 0 comments

    Dan Maloney12:00 PM
    OK folks, time to get the ball rolling. Welcome to the Hack Chat, I'm your moderator Dan, along with Dusan. Today we're pleased to welcome Agustin Cruz to talk about what he's been up to with metal 3D printing,

    I think I saw him log in earlier -- are you out there Agustin?

    Agustin Cruz12:00 PM
    Hello everyone

    Dusan Petrovic12:00 PM
    Hello and welcome!

    Agustin Cruz12:00 PM
    A brief introduction. Dan, please stop me anytime you want.

    Nicolas Tremblay joined  the room.12:00 PM

    Dan Maloney12:00 PM
    And apologies in advance if I put a "u" in Agustin. Muscle memory...

    Dan Maloney12:00 PM
    Go for it, I was just going to ask

    Agustin Cruz12:01 PM
    Dont worry. I think Augustine is a girl name

    Agustin Cruz12:01 PM
    My name is Agustin. I'm from Chile

    Agustin Cruz12:01 PM
    I have 2 Sinovac and 1 Pfizer vaccine shots in my body

    Agustin Cruz12:01 PM
    I think this month I will get the second Pfizer

    Agustin Cruz12:01 PM
    I'm an electrical engineer with more than 10 years of experience building laser machines, CNC machines, robots, laboratory equipment among other things. For the last 5 years, I'm working on this 3D Metal Printer.

    Agustin Cruz12:02 PM
    This project consists of an Open source, low-cost 3D Metal Printer for developing and low income countries, using an electron beam to sinter the metal powder

    Agustin Cruz12:02 PM
    So, the goal is to make 3D Metal Printing more affordable to the general public, hospitals, small institutions, organizations and companies around the world. Specifically for developing and low income countries.

    Agustin Cruz12:02 PM
    Dan, you can stop me anytime

    Agustin Cruz12:03 PM
    This printer uses an electron beam to selectively melt each layer of metal powder, causing the powder particles to fuse together.

    Agustin Cruz12:03 PM
    After one layer is complete, the build platform is moved down one layer in height. The re-coater comes in again with a fresh layer of powder, and the electron beam starts to induce the fusion of powder particles, causing the new layer to form.

    Agustin Cruz12:03 PM
    This process is repeated until the entire part is finished, making a solid metal part. Each layer height is around 0.05mm to 0.1mm thickness.

    TheRealDubz joined  the room.12:03 PM

    Nicolas Tremblay12:04 PM
    what kind of X-Y resolution?

    jfpayeur joined  the room.12:04 PM

    Dan Maloney12:04 PM


    3D Metal Printer

    Tired of printing plastic? This is the first Open Source 3D Metal Printer using an electron beam. The goal is to make 3D Metal Printing more affordable to the general public, hospitals, small institutions, organizations and companies around the world. Specifically for developing and low income countries.

    Read this on Hackaday

    Dan Maloney12:04 PM
    For reference

    Agustin Cruz12:04 PM
    I can continue if your prefer

    TheRealDubz12:04 PM
    any issues with cavitation? I assume some kind of flux is involved in the process

    George Albercook12:05 PM
    and x-y velocity?

    TheRealDubz12:05 PM
    in the powder I mean

    Agustin Cruz12:05 PM
    Currently there is an advanced functional prototype, with more than 5 years of research and development with its own capital. This prototype is used to carry out initial tests and verify technical aspects before making larger investments.

    Agustin Cruz12:05 PM
    The most important technical challenges are already 70% solved. The functional prototype is composed of a vacuum chamber made of stainless steel, a vacuum pump system, an electron gun, high voltage power sources, electrical connections, cooling systems, sensors, among others.

    Agustin Cruz12:05 PM
    At this time the prototype is capable of generating a 0.5mm diameter electron beam, focusing it on a metal surface and moving it in XY axis. In this way, it is possible to heat a metal piece using the electron beam.

    Agustin Cruz12:05 PM
    Currently, optimization of the electron gun is being worked on, evaluating different configurations to reduce the size of...

    Read more »

View all 2 event logs

Enjoy this event?



Interested in attending?

Become a member to follow this event or host your own