This is a nice first step and all, but there are a number of challenges here. The irregular sparking and popping noises imply that the metal laid down will also be irregular. This uses a regular MIG welder as the print head, and MIG welding only allows you to lay so fine of a bead. Large welds tend to be brittle due to internal stresses, voids, and the like.
The more successful commercial metal 3D printers build parts a thin layer at a time. A fine metal powder is sintered on each layer using a laser. This technique is called Direct Metal Laser Sintering (DMLS).
That's a pretty glaring omission. I imagine the prints look pretty awful, but it a neat idea. In the normal use a wire feed welder the arc (bright sparky part) would be uniform to create a bead. From what I saw in the videos they are using a "bad" welding technique that would build up the instead of penetrate the metal. They will need to replace/control the wire feeder and the voltage of the welder in order to better results.
Additive manufacturing pretty much always needs some sort of leveling phase to cope with z-axis irregularities. Without that you can't hold tolerance. Furthermore without support material you're limited in what you can build.
Looking at the pictures this seems like it makes metallic blobs approximating the shape. I suppose if you have a CNC to post-process it into something closer that may be fine. It'd be nicer to do the machining on the fly, but with the width of the material deposition it looks like it would drip down the sides if you did that.
With this design you might but you can get good essentially flat layers using the same essential process. There are existing commercial machines that use metal welding to do mixed additive and subtractive manufacturing. It's really a question of getting the welder dialed in so it creates a smooth enough surface. The weld will also fill into the small inconsistencies in height better than filament.
Perhaps manufacturing processes like laser sintering or 3D printing with a MIG welder have not become mainstream because traditional metalworking processes like casting, turning, and milling are so much faster and much more repeatable. Let me know when this thing can hold tolerances of +/- 0.0001". We'll probably have a cure for cancer by then.
Metal can be a tricky material to work with. It takes a lot of force manipulate. If you don't know what you are doing, you can very easily get seriously injured or even killed. To me, it would seem much more rational to try to build low-cost milling and turning centers that are small enough to move into a house without taking out the walls and simple enough to maintain where you don't need to have certified mechanics come every time you crash it. You're still going to have to make a considerable investment of time to learn how to safely and properly operate it, but that seems much more realistic scenario than emailing a file to grandma, having her put on her sunglasses, then pressing "Print," followed by 6 hours of sparks flying.
Don't get me wrong, I'm sure there are applications for additive metal manufacturing processes, but I believe that the cases where they are the best solution are few and far between.
I think your bar is a bit high. Standard milling tolerences are almost 50x higher than what you state. Casting is much worse. The point is that additive printing won't take over the metal world any time soon but it does have some advantages. Try to machine a hollow sphere for example. There are plenty of shapes that can't be traditionally machined.
How about something like SHIP2? They print the shape in the green and compress it using gas. This allows 3D printing of Inconel in shapes that require almost no machining after production.
I have welded before and I know that you need to clean each weld with a wire brush. I just can't imagine what is created is very strong. We need some pictures and some stress tests validating it as useful.
They might be able to reduce the oxidation on each layer by enclosing the whole thing in a box filled with an inert gas. (This is the recommended technique for welding titanium, for example.)
Flux causes slag, which necessitates cleaning with a wire brush. If you read the parts listing, you'll see that they are using a Miller 140 MIG welder, which can use an external gas source instead of flux wire.
[+] [-] TehCorwiz|11 years ago|reply
[+] [-] chromaton|11 years ago|reply
This is a nice first step and all, but there are a number of challenges here. The irregular sparking and popping noises imply that the metal laid down will also be irregular. This uses a regular MIG welder as the print head, and MIG welding only allows you to lay so fine of a bead. Large welds tend to be brittle due to internal stresses, voids, and the like.
The more successful commercial metal 3D printers build parts a thin layer at a time. A fine metal powder is sintered on each layer using a laser. This technique is called Direct Metal Laser Sintering (DMLS).
[+] [-] jeffmcjunkin|11 years ago|reply
[1] http://hackaday.com/2013/12/07/a-rostock-welding-3d-printer/
[+] [-] quizme2000|11 years ago|reply
[+] [-] claar|11 years ago|reply
[+] [-] JoeAltmaier|11 years ago|reply
[+] [-] jeffchuber|11 years ago|reply
[+] [-] samatman|11 years ago|reply
[+] [-] JoeAltmaier|11 years ago|reply
[+] [-] chuckkir|11 years ago|reply
Looking at the pictures this seems like it makes metallic blobs approximating the shape. I suppose if you have a CNC to post-process it into something closer that may be fine. It'd be nicer to do the machining on the fly, but with the width of the material deposition it looks like it would drip down the sides if you did that.
[+] [-] rtkwe|11 years ago|reply
https://www.youtube.com/watch?v=s9IdZ2pI5dA
[+] [-] tehzorroness|11 years ago|reply
Metal can be a tricky material to work with. It takes a lot of force manipulate. If you don't know what you are doing, you can very easily get seriously injured or even killed. To me, it would seem much more rational to try to build low-cost milling and turning centers that are small enough to move into a house without taking out the walls and simple enough to maintain where you don't need to have certified mechanics come every time you crash it. You're still going to have to make a considerable investment of time to learn how to safely and properly operate it, but that seems much more realistic scenario than emailing a file to grandma, having her put on her sunglasses, then pressing "Print," followed by 6 hours of sparks flying.
Don't get me wrong, I'm sure there are applications for additive metal manufacturing processes, but I believe that the cases where they are the best solution are few and far between.
[+] [-] merrillii|11 years ago|reply
[+] [-] nickpinkston|11 years ago|reply
[+] [-] RyJones|11 years ago|reply
[0] http://www.summitmaterials.com/near-net-shape/
[+] [-] contingencies|11 years ago|reply
[+] [-] immaceleb|11 years ago|reply
[+] [-] dustinmoorenet|11 years ago|reply
[+] [-] chromaton|11 years ago|reply
Argon is relatively cheap.
[+] [-] michael_h|11 years ago|reply