Forget Plastic: Molten Metal 3D Printers Are Coming
#3dprinting #metal
Nothing to show, they’re using a silly X/Y platform, no prototypes, just a bunch of “we’re going to do it like this”…and tomsguide reports on it? Must be a slow news day. They haven’t even proven the simple concept…
What do you use as a base plate as you need it to conduct and not stick. And that’s just one thing I can think off without seeing the design in the flesh.
On one hand, it’s “vaporware” (oh, the irony) - but the basic premise is reasonable, even if lacking in execution, so I’m glad they’re promoting the concept. But it did seem to me to be a lot of flash and lacking substance.
#doesntwork
It’s an interesting concept, but I’ll believe it when I see it. Plus they’re making a single, one-off machine for $20-$100k but plan to have a consumer model under $10k in a year? Something about that just sounds… very weird to me.
@Stephen_Baird - Not so strange, if you think of it as custom-car vs economy-car. The Tesla Roadster to the Sedan to the whatever-the-next-model-is.
@Charles_Reiche - why not? I mean, as a concept, not in terms of the actual implementation. The only immediate thing that comes to mind is that the machine needs to operate in an non-oxygen chamber, or vacuum, but metal deposition techniques have been around for some time. (http://www.youtube.com/watch?v=iLndYWw5_y8 for example.)
Technology is interesting
@Joseph_Chiu I would assume the difficult, self-developed, and expensive parts (the system for handling and depositing molten metals) would be the same in both the one-off printer and the consumer-level printer. It seems a little like trying to sell a prototype for big bucks, because it’s the very first, then mass-producing a copy for sale at a more reasonable profit margin.
I could be wrong, and there could be a definite difference between the two, but with such sparse details it just strikes me as slightly odd and a little questionable. But maybe that’s just me.
Thinking about this I’m sure the only real way to do this with low power is in 0 g. Its easier to use magnetic fields and hold the metal on course.
@Stephen_Baird Often, the price difference has to do with the scaling of production - when you are making 1 or 2 pieces, you make it “by hand”. For short runs, temporary tooling, and for large runs, more complex and more permanent tooling. The final material cost in the finished goods may be the same, but the engineering/setup costs for smaller runs could dominate.
Ball-park figure here, but for comparison, if I wanted a custom 4-layer PCB to make my own RAMPS-like board, and I only planned to make one, I’ll probably pay $200-$500 for one piece on a reasonable production time scale (not aggregating with @James_Laen_Neal - OSH Park, for example). ~$400-$800 for 20 pieces, and then if I made about 1,000 of them, about $10,000 (or even much less).
@ThantiK they haven’t even explained what their concept is. He just said liquid metal, then when on to explain applications. He described SLS well. They didn’t say anything about seeking a patent, so this would only they are using an expired patent, otherwise they’d be either infringing on an existing patent, or be exposed to copycats.
Sorry to sound negative, but this seems too fishy. I hope this is just a situation of poor video editing, because I’d love to see that technology democratized.
@Eric_Moy I mostly got from the article that they would be using some sort of inductive heating element, and then magnetically propelling the metal out.
@ThantiK Ah yes, they did mention doing something like an inkjet. My bad. This would be like a metal objet printer. That would be feasible as any material can be accelerated with an electric field; i.e., Ion mobility/Time of Flight mass spectrometry.
After looking in the RepRapWiki, I realized that this idea’s been tossed around a bit but not much progress:
http://reprap.org/wiki/Metal_deposition_print_head
The MetalicaRap looks interesting but incredibly expensive. Electron beam and vapor dep requiring a vacuum chamber. Sounds like the team either works in a lab, or has access to surplus semiconductor industry machines.
If they do intend to be non-porous (as compared to SLS) they’ll need a perfect bond, or weld in metals, from blob to blob. Not only will the little blobs need to be molten, the localized area of the part that they are spitting at will need to be molten as well. Like in welding, you need to wait till you get that shiny puddle before adding the filler (I am a horrible welder though).
If the thing is not printed in a very hot chamber, I’m also curious to how much heat treatment will be required. Seeing as the entire part is welded together, what is the likelihood that it will have a multitude of internal stresses. If they manage to keep the part from warping during printing, Once it cools from chamber temperature to room temperature, it may also warp. Unless they leave it in the chamber to anneal (this would be a REALLY hot chamber).
It definitely has potential, it’s got my gears turning. I just hope they get a handle on the thermal expansion issues. they should probably start with a material with lower CTE… but now I just realized, at molten tempertures, metal oxidize almost instantly, to the weld area will need to be flooded with argon or CO2 like in MIG/TIG welding.
Anyhow, sorry, got carried away. Good Luck to them 
Ah, I found this video of something similar to what they describe that was developed a Sandia National Labs.
If you are looking for metal 3D printing then https://markforged.com/ is a great place to start. i was looking in to their machines for a past project i was doing. and they don’t just print in metals like titanium but also carbon fiber and Kevlar.
One of the things i was looking for was being a desk top machine to go in the study which these can