Show off your welds!
 

I don't know if we've ever had a thread for teams to show off their welds and welded parts. So, let's do it! Here's one of mine from tonight. Probably not perfect, but I've never had a class in this, and I think it'll do for the purpose. I use a Miller Diversion 165 with a 3/32 tungsten and 3/32 filler rod. Box tube is 1/8" wall.

Re: Show off your welds!
 

A jig and turntable set up to weld a tube to a plate.

https://fbcdn-vthumb-a.akamaihd.net/hvthumb-ak-ash3/t15/1095946_10202899302384269_10202899301464246_64323_ 303_b.jpg

Our welders drank to much coffee last Sunday.

https://www.youtube.com/watch?featur...&v=rbKy0agjpa0

Re: Show off your welds!
 

Beautiful! The only thing I would have to say is to let off the pedal when you end the weld you got a little two hot at the end of that. Here is one of mine I use a Miller Diversion 180. I am a bit too hot at the start but it was hard became it was on a large alum truss so getting enough heat period was hard even after pre-heating with a MAP gas torch. Really nice weld though.

Weld: https://drive.google.com/file/d/0B7j...it?usp=sharing

Truss: https://drive.google.com/file/d/0B7j...it?usp=sharing

Re: Show off your welds!
 

This is by our best welder, A girl btw. Great work Jennifer!!!

Re: Show off your welds!
 

In to see what other teams do. I TIG weld for my team, but this year's welds were... less that satisfactory. Don't TIG when you're exhausted kids.

Looks great sanddrag. Are you going to zip up the other sides too?

When I taught welding almost all of the best welders were girls, and thus I am unsurprised ;) They seem to have an inherent advantage over guys.

Re: Show off your welds!
 

We welded most of our frame last year, and got some really pretty ones, too. I'll see if I can dig up some pictures.

This year, however, we're riveting almost everything together (with just a few welds.) This is due to our inability to repair a broken weld at a competition, which nearly ruined us at MSC last year.

Re: Show off your welds!
 

unfortunately, we do not weld our robot:( but funny you should make this thread cause every year, the Drive team is fascinated by how smooth a perfect the welds are done on the driver station, im sure its done by a machine but every year the first thing we look at is the welds.

Re: Show off your welds!
 

I would be stunned if a robot was used to weld such low-volume items as the player stations. A professional welder, or even a good amateur welder, can make some incredible looking welds.

Re: Show off your welds!
 

We overdid the welding last year, and have almost gone the other way this year. Rivets and bolts. Similar case, worried that a repair on some critical parts that were welded would take us out of the competition.

But we have some interested students so this off season we will be practicing welding.

This was last years frame. Planned on a corner climber that didn't work out due to time and weight. And some of my early aluminum work.





Randy

Re: Show off your welds!
 

Can you list your process parameters? (Things like filler alloy and thickness, base alloy and thickness, gas cup type and size, torch size, electrode type, size and point, current, voltage type and effect, gas mix and pre/post/welding flow, machine type, size, input voltage and duty cycle, joint preparation and position, etc..)

We might benefit from a thread about welding practices, material selection and post-weld heat treatment.

Re: Show off your welds!
 

Re: Show off your welds!
 

Not amazing, but looked pretty good when powdercoated. To his credit, our welder was doing 1/16" tubing onto 1/4" plate.

Re: Show off your welds!
 

Here's our frame. 100% welded.

http://wiki.team1640.com/index.php?t...0204_csm-2.jpg

Re: Show off your welds!
 

We used a Miller Diversion 180. 100% argon, and made sure the aluminum was really clean. That seems to be the key for aluminum. Used a stainless steel brush to mechanically clean the joints.

The Diversion 180 makes it easy, has presets for steel and aluminum. The only place where a bigger machine would have been nice is getting deep into corners and being able to change the frequency to drive th arc some more.

6061 aluminum, and 4043 (I think) filler. 3/32 tungsten and the cup for that size. Did not use a gas lens, but understand that can help. Part of the future practice sessions.

Mistakes made. Welded too much at once and heat warped the parts. Keep track of how much heat and take it slow. May mean restarting some beads part way through. Work far apart to minimize the heat.

The diversion is a good dual voltage unit as well. 120, and 240 with the change of a plug, just limits the upper end of the amperage provided. It is very light and easy to move as well.

Re: Show off your welds!
 

A more advanced machine with current pulsing settings can work miracles for heat management, allowing beads to be welded continuously with little warping.

Alternatively the operator can pulse the pedal to get nearly the same effect, but that's a somewhat advanced technique. Something else to add to the practice list :)

Re: Show off your welds!
 

Here's our chassis. 100% welded.

http://wiki.team1640.com/index.php?t...0204_csm-2.jpg

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!
 

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!
 

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!
 

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

Re: Show off your welds!
 

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