Chief Delphi - Show off your welds!

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Re: Show off your welds!

Unfortunately, we have no welding apparatus at our build space. It's such things that make us thankful for our ebmpapst engineering mentors. We should have bumper brackets good to go by the middle of week 6.

Re: Show off your welds!

We do a ton of welding, both to build the bot and build equipment, tables, fixtures, but welding isn't without its drawbacks. It's expensive and requires committed students which some years aren't very prevalent.

Re: Show off your welds!

Here's one from today. It's so fun to totally just nail one spot on.

Airgas guy told me the green tungstens are not for use with inverter machines like the Diversion 165. Wish they had told me that a year ago when I bought them. Anyhow, I switched over to the purple colored E3 tungstens (I think they're called) and it's a big difference. Real smooth buttery arc.

The only issue I'm having with these tungstens is that the arc wants to dance around a bit when starting, until you really punch it in with the pedal.

I did have a few welds completely blow out (yes, outward), and then the metal just would not accept a weld in that location no matter how clean I ground it out. It was really weird. I think I had a bad batch of metal, with contaminants or water in it. Anyone ever experience that?

Re: Show off your welds!

Quote:

Originally Posted by sanddrag (Post 1340485)

Anyhow, I switched over to the purple colored E3 tungstens (I think they're called) and it's a big difference. Real smooth buttery arc.

The only issue I'm having with these tungstens is that the arc wants to dance around a bit when starting, until you really punch it in with the pedal.

I was wondering what was in a purple electrode; I haven't seen those before. Turns out it's tungsten with 1.5% lanthanum oxide and small quantities of zirconium and yttrium oxides. I like the ceriated (grey) electrodes for 6061 aluminum with an AC inverter welder, and certainly prefer them to pure tungsten (green). Have you ever used those, and can you compare them?

(More information on inverter welders and electrode selection here.)

Re: Show off your welds!

Quote:

Originally Posted by sanddrag (Post 1340485)

Here's one from today. It's so fun to totally just nail one spot on.

Airgas guy told me the green tungstens are not for use with inverter machines like the Diversion 165. Wish they had told me that a year ago when I bought them. Anyhow, I switched over to the purple colored E3 tungstens (I think they're called) and it's a big difference. Real smooth buttery arc.

The only issue I'm having with these tungstens is that the arc wants to dance around a bit when starting, until you really punch it in with the pedal.

I did have a few welds completely blow out (yes, outward), and then the metal just would not accept a weld in that location no matter how clean I ground it out. It was really weird. I think I had a bad batch of metal, with contaminants or water in it. Anyone ever experience that?

Looking good.

I assume you're welding up a closed tube structure? If so, that's air heating up inside the tubes and pushing the molten weld material out from the inside. The areas they blow out get super contaminated with oxides and need to be completely ground out and/or cut away. Drill a small (1/16-1/8in) hole where no one will notice to vent out said gases and you won't have the blow-out problem anymore. I have encountered this issue welding aluminum, steel, and titanium.

I used to use thoriated tungsten for everything: steel, aluminum, titanium, etc. Having learned that its radioactive I've switched to using 1.5% lanthanated (gold/yellow band). Never used purple/E3 before... might have to give it a try.

Re: Show off your welds!

As it turns out, yep, I was welding up a closed tube, and I guess it was getting hot enough to where it was melting through, then blowing out. I can't believe I forgot about that. I've drilled a little hole every previous year. I just wasn't thinking.

Anyhow, I do like those new purple tungstens. Ran a couple practice beads just for fun.

Anyone else do welding. We need more pics in this thread.

Re: Show off your welds!

Don't know how to attached pictures so heres a link.

Using a Dynasty 200 with a DiamondBlack torch with Flexhead
settings:
balance around 61-64 %
frequency closer to 200 Hz
Amperage depends on what I'm welding but it's usually set for around 111 AMPS.
using a 2% ceriated 3/32 tungsten electrode (gray band)
filler rod is usually 1/16" occasionally 3/32" i believe it's 4043

Re: Show off your welds!

All very nice work. Almost makes me wish we could use TIG. But I know that we'd never be able to get all our welding done that way with the level of student commitment we have. And given that our chassis complexity demands out-of-position welds right out of the gate. So we use a 225A MIG with a spoolgun. Set to spray, it'll deliver nice sound welds with minimal practice.

Re: Show off your welds!

Hi guys,
One of our lead mentors does the TIG welding for our team, so here is our 100% welded chassis.

The weld was done with a Canox Redmaster 300 welder, green tip 3/32 electrode, pure argon gas, and ER 5356 3/32 filler rod.
https://drive.google.com/file/d/0B2w...it?usp=sharing
https://drive.google.com/file/d/0B2w...it?usp=sharing
https://drive.google.com/file/d/0B2w...it?usp=sharing

Re: Show off your welds!

Quote:

Originally Posted by Jonathan Cheng (Post 1343549)

http://i.imgur.com/frdygfp.jpg
How are these?

Temperature looks good, but hard to say for sure without seeing the back of the weld. Practice on keeping your bead width consistent, and don't leave a crater at the end of the weld, it's a great place for cracks to start.

Re: Show off your welds!

I'm not an expert on welding, but I thought you guys might like one on our robot. Check it out