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Video 3-D Printing with Molten Steel (Video) 104

Steve Delaire is making a 3-D printer that uses steel instead of plastic. Specifically, he's using TIG welding to build up layers of steel, just as most 3-D printers build up layers of plastic. He says he's "still working it out," but eventually hopes to use 3-D welding to make larger than life art pieces that are strong enough to be placed safely in public areas such as parks, where children are likely to climb on them. Steve's blog is called Molten3D, and it's a diary of his work, including the problems he encounters and how he overcomes them. He's not the only one doing metal 3-D printing; a Texas company has even made a printed metal gun. So there's plenty of people working in the field of what we really should call "additive manufacturing" instead of "3-D printing." But whatever you call it, every year we see this kind of process being used to make stronger and more complicated shapes, using an ever-increased variety of materials in ways that have been developed since this seminal paper, Liquid Metal Jetting for Printing Metal Parts, was written in 1997. (Alternate Video Link)

Tim: Steve, here at Maker Faire you have on display a machine that’s a little bit unlike most of the 3D printing equipment that I’ve seen here—because it’s a welding machine. Talk about the reasons for that.

Steve: Okay. Well, what I’m trying to do with this is copycat a typical plastic printer and use a welder instead and metal materials. So it is a TIG welding process, which is very common, and I am feeding cold wire feeding material into the weld puddle. To create a metal object instead of plastic. The end goal of what I am trying to do is to make public sized art with welded steel. As it turns out most public art has to be shown to be structurally sound. And so by using the welded process I’ll be able to show the engineering behind the product and it will be approved by the cities to be out in the public. A very important part, the key, in the process is being approved. So that’s the end goal. This is the bench test model—I am still working it out. The challenge is using open source slicing software in my application—it doesn’t quite exactly blend over perfectly. So I have to learn how to change the software for my needs. The welding equipment confuses the motion drive. So there are some lessons to learn there on how to solve that problem. But by and large it looks like it’s going to work. We’re getting some welding samples that are starting to look promising.

Tim: Can you show us the machine itself?

Steve: Sure. So the machine itself really copycats what’s called the gantry style printing machine. I’ve done it in steel because of the heat requirements. Being in a welded environment I can’t have a wooden structure—it’s going to burn. And I’ve eliminated as much plastic as I could for the same reason. So it’s mostly metal construction. In my drive system I’m using a cable to make the movement work because it will scale up. If I use the standard gear and rack system or pulleys and belts it doesn’t scale as well. With this I can get any length cable I want and it scales easily.

Tim: And the feedstock is pretty standard stuff?

Steve: Yes, absolutely. The feedstock is just standard MIG wire that you can get at Home Depot or Lowe’s or any welding supplier. It’s easily obtainable, and it’s not expensive. If you just use a steel wire for 2 lbs it is $12, $13; 2 lbs in plastic actually is considerably more money. I think it will match in the actual volume. My slicing heights for this particular machine is about 1 mm whereas in plastic it’s very common to see 0.2 mm. So my stack height is five times bigger per pass, so that 2 lbs of material will actually go quite a way.

Tim: How about the power requirement? I think you’re hooked up to some pretty hefty looking batteries back here.

Steve: Well, the battery, all of them here those particular batteries are recycled from an electric car that we have. It’s actually a 24 volt input for the motion control. And what I’m doing is, I’m separating out the power requirements of the motion control versus the power requirements in the welder. I want them to come from two different sources, to try and isolate some of the crossover electronic problems that this machine currently has.

Tim: Could you talk briefly about those problems you mentioned before?

Steve: The microcontroller has been quite robust but when the welding process starts up it creates a high frequency radio wave that then passes across that board and freaks it out. So my fix at this point is to start the welding and then start the motion. Separate the two things and it’s working. Ultimately, I need to solve this problem.

Being here at the Maker Faire I’ve had enough interest from people coming to see what I’m doing that I think I found somebody that knows what to do to solve this problem. And that’s been really good—I’ve made some good contacts for solving my software problems. So that’s been the real asset for coming here is to find people to help support this project. Ultimately, I hope this to be an open source thing. It’s called Molten3D and I’ve created a BlogSpot to share my ideas. I’m sure by me sharing other people will chime back in with “You could solve that problem by doing this”

Tim: To be clear, I want to make sure people realize that the size we’re standing next to is not the final size what you want to do, you want to scale this up, 2, 3, or 4 times.

Steve: Yes, absolutely. I want to be able to make public art pieces that are 8’, 10’ tall all welded sculpture type thing....

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3-D Printing with Molten Steel (Video)

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  • Some meta (Score:3, Insightful)

    by Anonymous Coward on Wednesday June 18, 2014 @03:35PM (#47265513)

    Some Meta

    The good:
    This isn't some naval gazing blog post by someone whos opinion we don't care about babbling about how 3D printing will change everything. In fact, I didn't see anything about future implications of this technology. This is just a blog by a guy building something really cool in his garage, and I like this.

    Maybe it won't pan out. Maybe it will be impractical. Maybe he'll hit some insurmountable wall. It doesn't matter, he's actually doing something! He has actually got a physical thing in his garage that he's tinkering with, and that's cool in my books.

    The bad:
    Bold comic-sans esq font. I'm not usually a font snob, but this is really hard to read. I actually copy+pasted the contents into a text editor to read it.

    • In fact, if you're working with molten steel, you're already into a level of industrial effort where casting is almost certainly a cheaper and faster choice.

      • It means materials in the device need to be resistant to temperatures exceeding 1370 celcius... probably exceeding somewhere between 1500-1700 celcius to be on the safe side.

        • Among other things. Safety, cost, energy requirements. Other things that basically say "Yeah, this requires substantial industrial planning and equipment"

      • by Anonymous Coward

        In fact, if you're working with molten steel, you're already into a level of industrial effort where casting is almost certainly a cheaper and faster choice.

        Yeah do sand-tray casting of complex shapes, you need expert casters and pattern makers. They are very hard to find these days. (In the U.K. when they recently built a replica of a 1940's steam locomotive, originally built in Doncaster, they had to hire a German company to cast the cylinders.) It would be much easier to find somebody who could set up a 3D printer.

        • So 3D print the casts?

          • I've always been a little surprised there isn't more talk about "lost wax" style casting with PLA prints. Does it fundamentally not work, or are most 3D printer people just generally not involved with metal casting (which would be understandable, it's a whole extra level of dangerous and prep-work to do at home)?

            • by laird ( 2705 )

              There are lots of people doing casting from 3D prints. You can 3D print the master in PLA, then make a plaster cast, burn out the PLA, and pour in metal. For example, [] . It works, it's just more dangerous and complex than most people want to deal with.

      • In fact, if you're working with molten steel, you're already into a level of industrial effort where casting is almost certainly a cheaper and faster choice.

        If you're mass-producing the same part, undoubtedly. But casting means you have to have a mold, which means a considerable overhead if you switch parts. At the limit, if you only produce a given part once, it makes much more sense to 3D print it.

  • This will suck. Some blotchy metal will come out. This will just be a welder with a robotic arm.

    Why not a real printing process, like powdered metal layed down and lasers? Or something.

    • Everyone makes awful, sputtered welds on their first few tries. Being able to lay down a good bead is not a skill that comes easily, not least of all when you're trying to build a machine that can do it from scratch.
  • Good luck (Score:5, Insightful)

    by Charliemopps ( 1157495 ) on Wednesday June 18, 2014 @03:53PM (#47265615)

    Good luck.

    I was a welder for quite a while. Molten steel behaves more like water than plastic. Steel "beads up" as you heat it. Being precise with welding is very hard. Plastic behaves more like frosting when molten so it's easier to use in a printer scenario.

    I think his big mistake is taking the ID of 3D printing and applying it to a martial for which it wasn't intended. I'd think he'd have better luck if he instead looked at Powdered metals: []

    In industry, they design a part, make a mold for it, press a mixture of powdered metals into the mold and then sinter it (basically the same as firing ceramics)

    ooo... hey look, I tried looking it up and that's exactly how they 3D print metal: []

    anyways, yea, that's the direction he should go. I'd use electro static charge to hold the shape and then use something like an Xray laser to melt/fuse/sinter it.

    • Re:Good luck (Score:5, Insightful)

      by CaptainLard ( 1902452 ) on Wednesday June 18, 2014 @04:13PM (#47265765)

      I think his big mistake is taking the ID of 3D printing and applying it to a martial for which it wasn't intended

      Maybe he just wasn't aware "they" have already chosen all of the materials which are allowed to be used in 3D printing and that no further attempts at innovation are necessary. He probably doesn't even know that no useful knowledge ever comes out of an experiment that fails at it's original intent.

      Or maybe the opposite of all that....

    • by unrtst ( 777550 )

      I think his big mistake is taking the ID of 3D printing and applying it to a martial for which it wasn't intended. I'd think he'd have better luck if he instead looked at Powdered metals: []


      anyways, yea, that's the direction he should go. I'd use electro static charge to hold the shape and then use something like an Xray laser to melt/fuse/sinter it.

      There is room for more than one tech.

      Sintering *may* make a more detailed final part, but this may make a stronger part.
      This machine is very likely to be less expensive in all aspects:

      * cheaper to build with more readily available parts (fairly standard welder rather than xray laser, for instance)
      * cheaper and more readily available feedstock (simple spools of mig wire)
      * much easier to work with on a large scale (filling a 10'x10'x10' box with powdered metal will be HEAVY, and clean up will be a bitch; this

    • by hey! ( 33014 )

      Molten steel behaves more like water than plastic. Steel "beads up" as you heat it.

      I wonder if this isn't a function of the high temperature you use welding. At lower temperatures iron alloys can be extruded and of course shaped by forging, neither process which would work with water.

      Most people don't realize, but the technology to melt iron didn't exist in most of the world until the early modern era. Only China had furnaces hot enough to reach the melting point of iron. European ironworkers used a "bloomery" furnace in which they roasted ore. Bits of solid but red hot iron would drop to

  • Well, besides confused microcontrollers? From his blog, he's using a 3D plastic printer to prototype the parts for this printer. Cool. Some test pieces in the blog photos, but let's see the sparkenmaken!
  • by Registered Coward v2 ( 447531 ) on Wednesday June 18, 2014 @04:02PM (#47265673)
    I saw a demo, around 2003, of a sintering machine the military used to build prepare parts in the field. Rather than shipping a part they could produce and machine it as needed remotely; all they needed was the appropriate instruction set and they were good to go. When I asked abut the strength and durability of the parts they said it was as good or better than normal spares.
    • It's as good or better than those other parts we're not using.

    • by Guspaz ( 556486 )

      While 3d printers that use sintering have their uses, the huge cost/weight and low speed of the 3D printer mean that you can ship a traditionally manufactured cost to wherever it needs to go faster and more cheaply than printing it in the field.

      • Define in the field. The GP stated for the military. putting a needed part on a special plane and flying it around the world is definitely more expensive and time consuming. If a part breaks at Sea for a Naval Vessel I would like to see Fedex get the part there faster. If the Part is in California, and you are in New York then yes you are correct.

        • by Guspaz ( 556486 )

          It's not like you're dispatching the part on a plane all by itself. The military has their own transportation network, moving all sorts of stuff, and unless you're on the front somewhere, shipping companies can do it too.

          Naval use, though, that's a pretty good counter-example, particularly on submarines where resupply is less frequent. It's much easier to ship something to a base somewhere than it is to ship something to a moving target.

      • by laird ( 2705 )

        You're right that SLS printers are slow and expensive, but they're still faster than physically shipping parts (hours vs. days), and if the value of time is high then it's worth using an expensive process to get the part faster. And it lets the unit be more self-sufficient, which is valuable when traditional shipping breaks down - many wars have been lost over control over supply lines.

        And an SLS printer and metal powder is much simpler to warehouse and keep supplied than a complete inventory of all needed

  • Interesting article, however, I suspect the editors are a bit mistaken. I strongly suspect that Mr Delaire is NOT using TIG welding in his machine, but instead is using MIG welding. Also I have to wonder if Mr Delaire is aware of []
    If not, he may be able to save a bit of effort and time by building upon the work someone else has already done.

    • by rolias ( 2473422 )
      Not a repeat, just another project, and it is TIG. Another project called Strongprint is using TIG because the mass of the print head can be quite low and move over a large, fixed print surface. The one you cited uses MIG and moves the print surface under the print head using a delta robot, while Strongprint mounts the print head on a delta robot, and Delaire's printer moves the TIG head on a gantry. []
  • Even with the "2.5D" limitations of a three-axes CNC machine, I still prefer subtractive manufacturing.

    • Nothing is as fun as plunging a 3/4" end mill 1" deep into some tooling aluminum and dialing up the feed rate to watch the chips fly.
    • Subtractive manufacturing is fairly wasteful of primary material resources.

      With that said, I snickered at his mention of how cheap steel would be. I would expect that the biggest expense of his rig isn't going to be the metal... it's going to be Argon. My last refill was $75 for a 45cu/ft tank. He's going to need to figure out how to enclose the entire rig in a sealed (positive pressure vented) box to help conserve gas. Just imagine... an enclosure big enough to do an 8' piece of art... 8^3=512cu/ft. I
      • by jasno ( 124830 )

        Nah, you recycle the waste. It wastes energy, because you're casting more metal than you need only to spend the energy tearing it apart and recycling it, but the metal, minus some oxidation, should recycle fairly easily.

  • Wonder if it works like this one, []
  • by GrBear ( 63712 ) on Wednesday June 18, 2014 @04:19PM (#47265817)

    Does this mean I can finally download a car?

  • When outlawing ownership is too difficult, oppressive lawmakers limit availability of certain items — like guns or drug paraphernalia or alcohol-making equipment — by banning their sales or transport (withing or across State-lines).

    If the end-users are suddenly able to make them themselves, some of these laws would not apply making us the people a little bit more free.

    • totally legal in the USA already to make your own gun out of metal by time tested methods, don't need this or any other "3D printing" equipment.

      • by mi ( 197448 )

        totally legal in the USA already to make your own gun out of metal by time tested methods, don't need this or any other "3D printing" equipment.

        Legal, but hard. 3D printing makes (or would make) it easy — extending the liberty to more people.

        • legal and inexpensive to do it old school. Making a shotgun wouldn't even be "hard" for moderate amount of skill, since it is rifling the barrel for rifle or pistol that is a bitch. The cost of 3D "printing" in metal is immense

          • by mi ( 197448 )

            legal and inexpensive to do it old school.

            Only if you know, what you are doing. I, for one, am a software guy and would not know arse from snout of most sorts of hardware problems.

            The cost of 3D "printing" in metal is immense

            That may not be a barrier to some people — it may be expensive, but it is still possible, whereas doing the "traditional" way is an outright non-starter for many.

            • plenty of videos on youtube by people with credibility to learn to use basic tools and to graduate to more advanced mechanical accomplishments, motivated person can go from zero to something these days...

        • by laird ( 2705 )

          You can make a better "gun" than the Liberator using a piece of wood and a drill, faster and cheaper than a 3D print. The US doesn't suffer from a shortage of guns or the ability to make guns.

          The only reason to 3D print a gun is because you really like guns and want to use 3D printing to get some press.

          • by mi ( 197448 )

            You can make a better "gun" than the Liberator using a piece of wood and a drill, faster and cheaper than a 3D print.

            My usage of the term "liberator" to refer to a new 3D-printing machine capable of working metal has — mistakenly — lead you to assume, I'm talking about a plastic gun model named "Liberator" made on a 3D-printer working on plastic...

            The US doesn't suffer from a shortage of guns or the ability to make guns.

            Certain Illiberal parts of the US — such as New Jersey — do suff

  • by Tom ( 822 ) on Wednesday June 18, 2014 @05:09PM (#47266419) Homepage Journal

    Video about steel-welding-3D-printer without actually showing it in action. *facepalm*

  • by Slayer ( 6656 ) on Wednesday June 18, 2014 @06:23PM (#47267201)

    There was a project going on, first at Carnegie Mellon University and then at Stanford's Rapid Prototyping Laboratory, where a very similar but more sophisticated process (Shape Deposition Manufacturing) was investigated to make precise metal parts with full strength (unlike the sintering methods mentioned here and elsewhere). A number of methods were used or tried to melt the metal, including TIG welding, laser fusing and induction heating.

    The biggest hurdle to success was the huge internal stress that built up in the process. Remember that one puts layer after layer of molten metal on top of the previous one. The new metal layer solidifies and shrinks, creating lots of compressive on the previous layer. Put down enough of these layers and the part will crack.

    And no, doing this process with Invar won't help, because Invar doesn't have this beautiful near zero thermal expansion close to its melting point.

    Lets hope the blogger reads what has been published about this process before he commits more effort and resources to his project ...

  • by hey! ( 33014 ) on Wednesday June 18, 2014 @06:54PM (#47267493) Homepage Journal

    Seriously, it's like we we've been having a conversation about home-built plastic ultralight aircraft, and then somebody says, "Hey, there's this company out in Seattle that makes aircraft out of metal."

    Doing it with molten metal is a new one on me, but people have been laser sintering metal powder for thirty years now, and I bet most of the dollar volume of 3D printers shipped today are of this type. They've been coming down in price too. I have a friend who's a research machinist who has one in his lab, and he tells me that the strength gap between cast metal parts and laser sintered parts has closed significantly over the years.

  • by Anonymous Coward

    Well, if you visit any of the big 3d-printing websites out there, you can already print & order your 3D model in a variety of metals including stainless steel, gold, silver, aluminum etc. 3d printing is not only in plastic anymore. They shoot lasers at metal powder to melt it (much like a laser printer).

  • So, there is a six-minute video of a guy talking about 3D printing. Am I out of line for expecting a video that shows the 3D printing? I'm not even interested in the first word the guy spoke much less six minutes of him talking. If you promise me "3D Printing with Molten Steel (Video)" is it unreasonable to assume that the Video is of 3D Printing with Molten Steel?

"If it's not loud, it doesn't work!" -- Blank Reg, from "Max Headroom"