welders welders welders

[MinnesotaDaveChalmers]

Hit the thermal overload constantly with a Hobart Tigmate (econotig) transformer based welder. Haven't hit it since getting the replacement, but at 310A for 20% duty cycle my gloves run out of duty cycle long before the machine does. :laughing:

Seriously, 20% is nothing. There's a reason all the bigger machines are amperage rated to where they're 60% duty cycle. You still have 4 minutes out of 10 for arc off, but with a 20% you can only run 2 minutes out of the 10 minute window. 12 minutes useful arc time in an hour is not a lot. Even for a student it's downright painfully slow.

+1
Well stated.

 

[Sodo]

20% duty cycle means you can weld for 2-minutes in a 10-minute time frame. :thumbdown:

Well that IS what it means, but i think TBN members want to know "is a 20% duty-cycle sufficient?"

Until I read or hear of credible reports saying 20% is NOT enough, I'm still the expert. Not because I "know", but due to LACK of credible info that 20% is insufficient (for 97% of TBN welder-purchasers).

Thomas why don't you ask those questions and become the "duty-cycle expert"? Members come to this forum for sensible advice - if you have it, post it. I'm a persistent mofo but easily de-thronable by someone who actually "knows". I was thinking of Mark at Everlast but even Mark won't flat out say what % a TBN purchaser should look for. Clearly TBN Members want to know.

If you can afford more than 20% then by all means hand it over to the salesman, he may have mouths to feed! At least your money's feeding local kids and you come home with the jewelry. Thats how I buy in some of my other hobbies. And I DID overspend some on my MultiMatic200.....

My MultiMatic200 is sort of a "20% machine" but in the midrange it's like 40-60%. Thats how it will be for most TBN members. Buy a 20% machine and you will never have a problem.

 

[Jim Timber]

Oh, and my Hobart handler 125 is a dog and will turn itself off if you run it too hard/long. I found that out trying to seam weld the perimeter of a intrusion resistant vent on the side of a cargo container. It was a rude awakening going back to a 120v machine from my Miller Invision 354MP that'll run 100% at anything under 25V.

Duty cycle is as relevant here as PTO horsepower, or hydraulic system flow and pressure. Anyone who thinks otherwise just doesn't know what they're talking about. If you need 2900psi to lift the loader at it's rated capacity, but you only feed it 1500, you're going to have problems. If your tiller needs 5hp per foot, but you only give it 2, you're going to have problems. If your work needs full rated power to get the weld hot enough, you're going to be thumbing your exit for a long time if your welder can't keep up.

Now if you want to get esoteric and talk about MIG guns or TIG torches, those are rated at 100% duty cycle and I'm a fan of not using a 300A gun if you don't have to. The last shop I was at they had 300A guns on 300A power supplies, but were only running about 150A (pulsed - where they had 100% duty cycle ). We could've had 200A guns and saved 50% of the weldor's fatigue without ever thermally stressing the guns, but someone in purchasing had their head up their butt and everyone on the floor suffered.

 

[Shield Arc]

i think TBN members want to know "is a 20% duty-cycle sufficient?"

Not for me it isn't!:thumbdown: And I'm just a hobbyist welder.

 

[Sodo]

OK you two guys are what the 3% in 97 is for! The other 97 can't outweld a Hobart 125, they don't have that many projects. Hey I'm quite the stud in my memory too. Except I've forgotten how long ago that was.

Hey wait a minute if you guys are doing that duty-cycle we wanna see the projects! Thats what the forum wants.

 

[Jim Timber]

The problem with a machine that's nameplate rating is derived from a 20% duty cycle is that they have very low output at a useful run-time interval. When you have a machine that starts out at 20% at 180A, when you get down to 150 you might be up to 35%, drop down to 125A and now you're up around 45%, and by the time you reach 60% you're sitting at a whopping turd of a 90A output.

Do you know what 90A on a MIG will safely weld? It's the bottom limit for 16 gauge! 1/16".

So if you only do really light stuff and it's 1/8" wall, you still need 150A.

 

[MinnesotaDaveChalmers]

Oh, and my Hobart handler 125 is a dog and will turn itself off if you run it too hard/long. I found that out trying to seam weld the perimeter of a intrusion resistant vent on the side of a cargo container. It was a rude awakening going back to a 120v machine from my Miller Invision 354MP that'll run 100% at anything under 25V.

Duty cycle is as relevant here as PTO horsepower, or hydraulic system flow and pressure. Anyone who thinks otherwise just doesn't know what they're talking about. If you need 2900psi to lift the loader at it's rated capacity, but you only feed it 1500, you're going to have problems. If your tiller needs 5hp per foot, but you only give it 2, you're going to have problems. If your work needs full rated power to get the weld hot enough, you're going to be thumbing your exit for a long time if your welder can't keep up.

Now if you want to get esoteric and talk about MIG guns or TIG torches, those are rated at 100% duty cycle and I'm a fan of not using a 300A gun if you don't have to. The last shop I was at they had 300A guns on 300A power supplies, but were only running about 150A (pulsed - where they had 100% duty cycle ). We could've had 200A guns and saved 50% of the weldor's fatigue without ever thermally stressing the guns, but someone in purchasing had their head up their butt and everyone on the floor suffered.

Completely agree - good analogies. I switch to a 17 tig torch for little stuff instead of a 26.

I have a 120v mig on the shelf that rarely ever gets used anymore. Turns out switching back to it I completely forget about trigger time and it gets hot and starts welding crappy.

Fortunately the mig gun on my millermatic 210 is small and light enough to not really notice it - but a 300 amp gun is kind of heavy and would be annoying to wrestle if not needed.

 

[Shield Arc]

Do you know what 90A on a MIG will safely weld? It's the bottom limit for 16 gauge! 1/16".

So if you only do really light stuff and it's 1/8" wall, you still need 150A.

I've said it before, and I'll say it again! When it comes to Mig welding there is no substitute for power.
Here you guys be the judge.

 

[Jim Timber]

I've had a 300A gun on my steel rig since I got it, and upgrading to a lighter one has been on my mind ever since. The thing holding me back is that I have so many of the darn consumables for it, that I don't want to make them all worthless.

I run a #20 water cooled for the TIG with a gas lens and I don't find the size is a problem at all 80% of the time. The last few days I was between 150-250A depending what I was doing, so having that range is nice. My water cooled torch is far more flexible than the air cooled 150A was. I didn't even put up with air cooled when I was still learning. Those things are unwieldy.

 

[roadhunter]

I had this same discussion with my crews when I was in the marine construction business about 10 years ago. Everyone wanted a 250 amp Bobcat (or bigger) on their work boat. I started paying attention to what they were doing and noticed that 90% of the time they were only running about 120 amps using 1/8" 7018. Every now and then they would use 3/32 or 5/32 but that was it. Machines never went over 160 amps or so and that was rare. I dropped back to a smaller Bluestar machine that weighed quite a bit less, cost less, and burned less fuel and it did everything they ever needed. I still have a little portable multiquip welder that is only 135 amps but runs 1/8" 7018 just fine and weighs 100 pounds while burning little fuel. I think having a big amp machine is more "cool" than necessary for most people who likely do not have the need or even the welding rod to go over 200 amps but tell you that you need a 200 amp machine with a high duty cycle for some reason.

I have a PA-300 but I almost always just use my ESAB 161 because it runs what I use (3/32, 1/8,and 5/32) just fine. It's nice having a big machine but the only rod I have that requires more than 200 amps is cutting rod so in reality I have no use for welding anything over 200 amps.