A 3D printer based on a MIG welder
Already have an account? Log in.
To make the experience fit your profile, pick a username and tell us what interests you.
The 3D printer is made using the following components
The first print I did with this printer was just bad. And the reason is I couldn't wait for the shielding gas to show up. From the beginning I intended to use the smallest welding wire possible (0.020). But I didn't have that on hand or the shielding gas when I go the machine together for the first time.
In my impatience I decided to try a print using (0.035) MIG Flux-core wire. That was a mistake.
The current required to melt this wire and deposit a the rate I needed kept tripping the breaker. Also my feed rates where to high so the weld kept skipping ahead of its self.
As you can see it was just a mess.
Another lesson learned from this experiment is that 14Ga steel is not thick enough to print on to. The plate warped like crazy. I have done some work on the very big and fancy 1.5 Million dollar machines and they print onto a 1 inch steel plate to prevent warpage. I guess I need a thicker plate :S
you would have to put a D.C. Clamp meter on it to see what the current draw. But these are rated at 20% at 90A. What size wire are you running
I will be using 0.020. When I tested it before it was pulling about 35A. But i will probably need more because the weld deposit wasnt great.
You mean .023? 35 amps is really low for that. I don't think your weld parameters are anywhere close to what they should be.
At Cranfield we've been playing with this as well.
Lots of papers published. We've been using rolling afterwards to try to normalise the grain structure in the metal. We now also have the worlds largest 3D printed metal part!
http://waammat.com/blog/have-we-3d-printed-the-biggest-metal-part-ever
It's important to get it suitable for aerospace because we have a massive ratio between the size of the metal we buy and the actual volume of the finished part. If we can reduce that then there is less environmental impact and everyone is happier.
Thats very interesting. looks like you guys are miles ahead of what I am doing. I will continue to examine these papers as the project continues. Still waiting on Argon at the moment....
Maybe but it uses a very expensive robot to do the work. Do consider whether you can use post pass rolling. It really improves the fracture toughness of the finished piece.
What is post pass rolling? I'm not a welder, but this sounds important.
Post pass rolling is when you apply high pressure via a roller to the bead you just laid down. The crystal structure of the metal from the weld is quite directional and has a lot of large crystals. This means it has low fracture toughness and is not the same strength in all directions. The post pass rolling causes the grain structure to recrystalise as smaller equiaxed grains which gives you much better material performance. The affect is similar to what you get in annealing a piece of metal.
Dont forget, those little machines only have a 20% duty cycle. Thats 2 minutes on and 8 minutes off. Other wise the best case scenario is the internal thermostat will trip, worst case, you fry the transformer. (I used to be a welding service tech)
Right now it is pausing after every layer for a while. This also helps some of the heat leave the part. To be honest I wasnt thinking about the health of the welder when I wrote the software :S.
If we are on a very low heat is this duty cycle still applicable? The thin wire doesn't require much heat to deposit.
roboteurs
TTN
Gorky
Charlie Godfrey
Sam Smith
A good way to increase efficiency of the welder used for printing would be to contain the machine in a housing that keeps it pressurized with Nitrogen to help strengthen the parts that are printed while increasing consistency in the arch. Also you could do a 1 stage CNC cut to build the base of the part that could be cleaned up after printing. I managed to grab a transformer out of an old flux welder. I think I'll start experimenting with it.