Video 3-D Printing with Molten Steel (Video) 104
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....
Some meta (Score:3, Insightful)
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.
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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.
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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.
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Among other things. Safety, cost, energy requirements. Other things that basically say "Yeah, this requires substantial industrial planning and equipment"
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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 but...to 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.
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So 3D print the casts?
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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)?
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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, http://3dtopo.com/lostPLA/ [3dtopo.com] . It works, it's just more dangerous and complex than most people want to deal with.
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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.
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Why would there be any size limitations to laser sintering? I don't see any reason why it can't be scaled to any size required. SpaceX is building rocket engines using the process, for example. The rocket engines in question aren't exactly huge, but they still put out more than 16 thousand pounds of thrust.
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Laser sintering is commonly used the term when plastic parts are produced: https://www.additively.com/en/... [additively.com]
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Laser sintering is commonly used the term when plastic parts are produced: https://www.additively.com/en/... [additively.com]
I'm not sure what you're saying here. If you mean that the word "sintering" is used mainly when plastics are involved then I'm afraid you're mistaken. It's used when referring to sintering as opposed to melting; melting and sintering are quite different and produce very different finished parts. The question of whether plastics or metals are normally sintered or melted is unrelated.
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The company that makes the 3D printers SpaceX use call it Direct Metal Laser Sintering. Not selective laser melting.
http://www.eos.info/04ea46b971... [eos.info]
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Except the metal is not actually melted, it's sintered.
If the metal is melted it's either going to bead up or flow across the surface it's sitting on due to surface tension.
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Why would there be any size limitations to laser sintering?
Because the bed holding the part and the powder that's going to be sintered needs to be moved with very good precision. It also needs to be at least as deep as the part you're making. It's generally very difficult to get large things to move small distances.
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If it is large enough, why not move the laser instead?
You may even be able to do this by reflection without moving more than a very small surface which reflects the correct wavelength. This does not seem like an problem which cannot be solved.
My first thought as to what would stop it is the amount of energy required, as lasers are not very efficient, and melting (or sintering) large objects may take enough energy that the losses involved in transferring energy through a laser may make it inefficient compar
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If it is large enough, why not move the laser instead?
In an SLM machine you have a cavity that is filled with a fine metal powder, the laser selectively melts/sinters parts of that, the base of the cavity moves down slightly and more powder is added to the top. Rinse and repeat until you have a solid part in the cavity surrounded by the powder that wasn't touched by the laser. I'm not going to cop-out and give a link to wikipedia, but if you go there and only look at the block diagram you'll see why the bed needs to be moved with precision at least equal to th
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"Why would there be any size limitations to laser sintering? "
Exactly. And the 'small' ones to print guns, cost less than 2D Laser Printers 30 years ago, dollar for dollar, even without considering inflation.
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Wow (Score:1)
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.
Re:Wow (Score:4, Interesting)
This guy wanted to be able to weld cool stuff without having to sit there holding a welder for hours at a time, plus he wants to have the welds be of uniform quality. What makes this a "3D printer" is that it uses an X-Y drive rather than an arm with elbow/wrist joints like most robotic welding machines.
dom
But that's the thing. If the environment isn't also controlled, the weld will not be of uniform quality. Welding is an art. You have to pay close attention to ambient conditions, the material being used and the settings on your welder. You need more or less Gas pressure, to adjust the gas mix, higher or lower welding speed, and need to change the voltage. You can also reverse the polarity of the weld depending on if you want the puddle to push or pull based on the direction you're welding. When I welded for a living, storms coming would mean I had to re-setup my machine if I was on a big job. I don't know if it was the barometric pressure, temperature or humidity that did it, but it was definitely something we had to deal with. As soon as I'd lift my helmet to make the change (back then there were no auto-dimming helmets) I'd see everyone else in the shop doing the same thing. Moving to someone elses welder meant re-setting it up to, so personal style must have had an effect as well.
On assembly lines they do just that... they control the environment. It's at a relatively constant temperature, humidity and the welding arm is doing the same exact weld over and over again so they operator can program exactly what it's supposed to do. But it's by no means as simple as feeding in a cad file and pressing "weld" You can do that for sure... crappy welds are good for several metric tonnes of force and can hold on a bumper as well as a good weld... but you're not going to get consistent quality or a "Pretty weld"
Re:Wow (Score:4, Funny)
Cool, sounds like a job for sensors and algorithms.
"Anything you can do I can do better..." sung the old computer...
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Welding identical parts with predictable properties in the same places is one thing, and robots are ideal for it*. So long as there's a need for custom fabrication and patching damaged parts there will be work for human welders.
*Probably why many earlier robots were used for just that, although spot-welding rather than arc.
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If you think you can't train a computer vision system to do it... Sure, maybe it's 20 years before it's cost effective(although for underwater welding...), but it's coming.
If you can boil it down to an algorithm, however complicated, you can get a computer to do it.
Eventually the computer does it better, because it has more sensors than you, thinks faster, has finer muscle movements, and can execute more complex algorithms than you can.
We're about to see this with driving.
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But that's the thing. If the environment isn't also controlled, the weld will not be of uniform quality.
Depends - I recall welding kits a couple decades ago that used preheat torches and submerged the arc under a pile of powdered flux, which made the environment pretty uniform and automated (at least good enough for x-ray inspection - the parts being welded were steel bridge-beams). The welding kit was a 1/4-ton monster that ran along sections of track, which in turn attached to the steel by way of strong-assed magnets. The operator only had to set the machine up for proper amperage, make sure the flux hopper
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True, but that's because humans do it by hand, and are not necessarily aware of all the changing variables, let alone be in a position to do anything about them. In theory a machine that does have the appropriate sensors would always do a better job as a result.
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Has anyone seriously suggested that 3D printing will lower the cost of mass production? The cost of prototyping and small runs maybe, but for anything where even a few tens of thousands of units are produced, modern manufacturing techniques promise to be cheaper while delivering a superior product for the foreseeable future.
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Yes, there are people who really believe we're at the dawn of Star Trek because a hot glue gun on a stepper motor made a Yoda coffee cup.
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mostly, but not always (Score:2)
Some really intricate parts are cheaper to 3D-print than to try and cast/forge/machine traditionally. Think hollow structures with stiffening ribs or cooling channels inside, or other similarly complicated shapes. The SuperDraco rocket engine falls into this category (though of course also is a small production run).
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Good luck (Score:5, Insightful)
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: http://en.wikipedia.org/wiki/P... [wikipedia.org]
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:
http://en.wikipedia.org/wiki/S... [wikipedia.org]
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)
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....
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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: http://en.wikipedia.org/wiki/P... [wikipedia.org]
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
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Copper and tin are expensive.
Tin: $22,500/tonne
Copper: $6,700/tonne
Steel: $385/tonne
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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
K, so is there a vid to show us what it makes? (Score:2)
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You can already run your programs on a mainframe - just as fast as this microprocessor BS would be, if not more so.
Interesting but not new (Score:5, Interesting)
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It's as good or better than those other parts we're not using.
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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.
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I'm not necessarily debating the utility of using a 3D printer for small orders, I'm arguing that sending them out into the field for military use doesn't really make sense. The parts are probably already manufactured, so the time/cost difference is between simply shipping an already existing part, versus shipping a very large and heavy metal printer out to the front somewhere. Shipping doesn't take very long, so the low speed of 3D printing means you'd probably get the part faster by shipping it rather tha
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Submarines, and other naval use? Perhaps. But the aircraft flying to Afghanistan are already going to be flying there for all their other stuff, it's not like you're dedicating an entire aircraft for one item.
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Sure, there would be regular supply schedules. But that means that the part arrives weeks or months after it's ordered. Which means either maintaining a large inventory of spares before they're needed, or waiting weeks or months while equipment is out of commission.
With an SLS printer, they could have the part in a few hours. So if the value of time is high, it's worth the cost of the SLS part.
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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.
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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.
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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
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It works fine without Flash if your machine pretends to be an iPad.
Mostly a repeat. (Score:2)
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 http://hardware.slashdot.org/s... [slashdot.org]
If not, he may be able to save a bit of effort and time by building upon the work someone else has already done.
Re:Mostly a repeat. (Score:4, Informative)
Top of his blog it says TIG.
The top of his blog post says "using ... a TIG machine". TIG welding is not the same as MIG welding: with MIG the wire is one of the electrodes and is fed using a variable speed motor through the torch, with TIG the wire is held separately in one hand in much the same way as it is with brazing and the torch is in the other hand. I think he's used parts of a TIG welding machine because that's what he happened to have. There's no reason I can think of why the same couldn't be accomplished using a MIG welder.
Of course this would be easily settled if the video showed the machine in action or the blog had any sort of description or diagram of how the machine works on either of the two pages.
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CNC (Score:2)
Even with the "2.5D" limitations of a three-axes CNC machine, I still prefer subtractive manufacturing.
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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
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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.
Additive and Subtractive machining (Score:2)
another (Score:2)
Comment removed (Score:3)
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Yes, but the twist is that it won't be roadworthy, and will look like a mix of the Flinstone's car and one of Koopa's police transports [smbmovie.com] from that gawd-awful Super Mario Bros movie they made back in the 90's.
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A major liberator from opressive laws... (Score:2)
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.
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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.
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Legal, but hard. 3D printing makes (or would make) it easy — extending the liberty to more people.
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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
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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.
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.
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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...
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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.
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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...
Certain Illiberal parts of the US — such as New Jersey — do suff
fail (Score:3)
Video about steel-welding-3D-printer without actually showing it in action. *facepalm*
This has been done and it failed (Score:3)
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 ...
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Uh.... Metal 3D printing is new? (Score:3)
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.
Um (Score:1)
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).
Where's the video? (Score:1)
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?