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.
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....
Re:Lower costs of production (Score:2, Insightful)
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.