MIT researchers demonstrate rapid liquid metal 3D printing technique
tctmagazine.com
tctmagazine.com
I hope we can see someone else take up the mantle on complex 3D printing manufacturing. There's an Indian space company that is trying to do what Relativity did. I hope it works out for them.
I have two resin printers and a PLA printer and I never expected at-home capability to get this far this fast.
But, that's still all effectively plastic we're talking about. I think the problem with metals is still well.. metals. The same types of metallurgy needed for 3D printing have been researched and hit almost a dead end with injection molding (I know there are some metal injection molding systems out there, but it's not hit anywhere near the strength of machined steel yet)
But there’s a ton of people out there with jig designs to spiral cut a normal cylindrical bottle and feed it into a hotend that creates filament from it. Here’s one example https://www.printables.com/model/768657-petalot-plastic-bott.... YouTube has dozens of videos of these in action. Generally speaking you won’t get as good of results as commercial filament since filament diameter needs to be carefully controlled and it affects flow rate which then affects resulting print quality. If you print something simple, large, and practical it’s fine, if you need something finely detailed it can be fiddly.
Is there other data to support that claim we can browse? I was under the impression the opposite was true but would love to know more if i'm missing something.
As the technology improves, I am skeptical of the necessity of sacrificing resolution. I can think of a half-dozen ways to improve on this as it moves from V0 to V1 to V2.
The video mentions post-machining, but aside from that, we have:
- More sophisticated media than uniform glass pallets. In particular, an outline could be preplaced, so it is more like casting. For example, one could have large glass pieces, smaller glass pieces, etc. arranged prior.
- Combined methods, where this prints the coarse shape, and slower techniques fill in details. This could even be the same technique but with successively smaller nozzles.
And simple process improvements (esp. refining nozzle design, temperature, and flow rate, so in some ways). I suspect moving from liquid to something more like extrusion, could help as well. Extrusion can be quite precise. Better process control, with some form of feedback loop, would help too. Imaging aluminum in realtime through the glass pallets in realtime should not be fundamentally hard.
By "not hard," I mean "known engineering process with known technologies" (e.g. solvable, but a serious multiyear engineering effort).
First press release + video I've seen from MIT which doesn't oversell / overhype results or grossly exaggerate potential impact. That's refreshing too.
There are already good metal printers. They're usually sintering systems - put down a powder and fire it in a furnace. There are systems for 3D printing sand molds for casting.[1] Both of those processes are much more precise than this one.
Metals do usually have a phase in which they're solid, but malleable, and can be worked with modest forces. "Modest" usually means hammers, large presses, or a rolling mill. A good metal extruder working with red-hot but not molten metal would need to be able to apply similar forces. That's what the 3D printers that work with wire and are similar to welders do.[2] There's directed energy deposition, which converts metal powder to molten metal for a fraction of a second at the deposition point.[3]
This liquid system has the same problem as the 3D printing systems for concrete that were being touted a few years ago. Some kind of molding or die is needed to guide the material at the point the metal becomes a solid, or the result is very rough.
[1] https://www.voxeljet.com/3d-printing-solution/sand-casting/
A clever enough idea, but the results are mixed. It's limited to fairly simple 2d shapes and the quality of the "prints" are quite poor and require a lot more post processing than true 3d metal printers.
They're very expensive for that reason. It's hard even for precision machining.
Injection molding processes I've seen have super-tight tolerances. Something like plaster or sandcasting do not.
Ceramic is cheap enough that this might be okay.
Removal would be a pain. Probably some chemical which melts ceramic but not metal. Perhaps something mechanical which relies on ceramic being brittle to break it up. Dunno.
Right now it is in a bed of fine glass beads that the printer drags through as it goes, so this is kind of a similar approach. For one offs or prototypes this might be good, but when you print more than one of something than a mold likely makes more sense.
Sand is cheap, and should be easy to 3d print, even for one-offs.
There are downsides, too: printing is slow, and the build area is small, furniture parts not gonna fit there.
For a comparison, that's about ten times the amount of energy you use running your microwave to heat up a ready meal, for every kilogram of aluminum you want to form.
Also, if you have a $1M machine then the machine-time really adds up.