Need my first welder. What to get?

[Mad Machinist]

Originally Posted by Static-XJ

There's a big difference in 140A @ 16V, vs 140A @19V. Only one of those is possible on 115V, 20A input.

Higher voltage does not equal higher duty cycle. It equals a smaller primary power cable. The duty cycle for a DeltaWeld 302 is the same weather it's wired for 230V or 460V, the input draw is 42A vs 21A respectively.
If you're talking about a MM140 and MM180 when you say higher voltage = higher duty cycle, then yes the higher voltage machine has a higher duty cycle but not because of the input voltage. It's easier to see when you look at machines capable of 230V/460V operation since 115V is capped at 20A. To get a '180 class' machine on 115V would take about 45A.

I am blessed enough to work with pipefitters and boilermakeers that hevae been welding longer than I have been alive. And I am 37 years old. I had a discussion with them about the thoughts on a 110 MIG not being able to weld the heavy stuff and the welding instructor/inspector there went on a profanity laced tirade that would have made a sailor blush.

To sum this up in a few words, if you cannot weld wth a 110v anything, THEN YOU NEED TO LEARN HOW TO WELD. If you need a 230/460 volt machine, then the welder is compensating for your inability to weld.

We use the crap out of these machines in a heavy mining environment and they work flawlessly. I could weld before I started here and had the same opinion about 110v anything. Well, under these guys, my welding has gone to an art form.

Under the AWS D1.1 and 1.3 Structure Welding Codes, there is ONE accepted practice for a MIG certification. E71T-1x flux core wire shielded with gas. That is it, no more, no less. Why do you think most roll cages are Heli-arced? It is an easier process to pass certification. The company I work for actually requires a 110v certification on 1"

The rule of thumb for MIG is 1 ampere per .001 of thickness. So a piece of 1/8" plate would be set at 125 amps. Most name brand welders out there now will still maintain around 18 volts at that level.

I can weld 1" in a single pass with our 460 volt MIGS and deal with a MASSIVE amout of welding draw even with heavy tacks

[Mad Machinist]

Originally Posted by Static-XJ

There's a big difference in 140A @ 16V, vs 140A @19V. Only one of those is possible on 115V, 20A input.

Higher voltage does not equal higher duty cycle. It equals a smaller primary power cable. The duty cycle for a DeltaWeld 302 is the same weather it's wired for 230V or 460V, the input draw is 42A vs 21A respectively.
If you're talking about a MM140 and MM180 when you say higher voltage = higher duty cycle, then yes the higher voltage machine has a higher duty cycle but not because of the input voltage. It's easier to see when you look at machines capable of 230V/460V operation since 115V is capped at 20A. To get a '180 class' machine on 115V would take about 45A.

I do this everyday, so I am not going to argue with you. IF YOU need a 230/460v+ class machine to get a good weld, then as per the profanity laced tirade the welding instructor/inspector here went on, LEARN HOW TO WELD AND QUIT LETTING THE MACHINE COMPENSATE FOR YOU. I am 37 years old and this guy was welding before I was born.

[Static-XJ]

Point I'm trying to make is a 110v machine doesn't have the juice for some wires. I'd argue that .035" ER70 is out of a 110v's range. At the voltage necessary to melt off the wire on anything thicker than about 18ga there simply aren't enough amps available. Self shield wires running EN take fewer volts and therefore don't present this problem.

I suppose I'd better learn to weld pretty quick, because in about 30 minutes I'll be welding 100kpsi steel using .045" ER100S-G wire, per an ASME Section IX qualified procedure at 26V 300A, and all welds on this job require 100% VT on roots and finals, and 100% MT or PT where the mag yoke doesn't fit. I should probably drag my HH135 in with me since if I can't make these welds with it, then I souldn't be welding at all.

[vegasloki]

Originally Posted by Mad Machinist

Why do you think most roll cages are Heli-arced? It is an easier process to pass certification.

Except that most cages, and tubing based race cars are GMAW welded and not with 120 volt machines. NHRA and IHRA require GTAW on faster cars with 4130 gages and some of the higher end stock cars and sports cars use GTAW for the cages and GMAW for the frames but by and large, most tubing based race vehicles are are welded using the GMAW process. There are limitations that 120 volt welder on a 20 amp circuit can't overcome. It's Ohms Law for starters. It's not a perpetual motion machine so you can't get more current out than you put in.

The other obstacles are duty cycle and transfer modes. The little welder is generally limited to short circuit mode as it doesn't have the current capability to do globular or spray arc modes. ( modes explained for those not sure http://www.thefabricator.com/article...modes-for-gmaw ) 1/8" on a single pass is about as good as a 120 volt welder on a 20 amp circuit can do. That's not to say there isn't a place for a 120 volt welder, we use a Lincoln 140T a the track so we don't have to buy a bigger generator or can go up to the tire barn and use the 120 on the side of the building. We're generally fixing nothing larger than gauge or 1/8" using flux core. That little welder has build about half a dozen cars over that last five years but it's pushing it.

However, in the shop these days it's at least a minimum of 180 amp class machines (which by their very nature require 220 as any 120 circuits above 20 amps are rare in most situations) and most folks doing it for real are using 250 amp class machines.

My direct experience comes from 10 plus years of racing and now having a business that supports the fabrication and operation with respect to building hobby race cars.

[vegasloki]

Originally Posted by Static-XJ

Point I'm trying to make is a 110v machine doesn't have the juice for some wires. I'd argue that .035" ER70 is out of a 110v's range. At the voltage necessary to melt off the wire on anything thicker than about 18ga there simply aren't enough amps available. Self shield wires running EN take fewer volts and therefore don't present this problem.

He doesn't understand the processes or the capabilities of his machine. Case in point, when someone tells me the weld for a living, everyday then says something like "Heli-arced", that tells me they aren't as familiar as they think they may be.

OTHO, when I hear...

I'll be welding 100kpsi steel using .045" ER100S-G wire, per an ASME Section IX qualified procedure at 26V 300A, and all welds on this job require 100% VT on roots and finals, and 100% MT or PT where the mag yoke doesn't fit.

That says to me the person that wrote that has been welding for a while and is indeed familiar with the processes and capabilities of the various machines.

[atblis]

Multi pass v. Single Pass? Can a 110 machine do 1/4" in a single pass?

[David D]

Originally Posted by atblis

Multi pass v. Single Pass? Can a 110 machine do 1/4" in a single pass?

No.

[Todd W]

Originally Posted by vegasloki

He doesn't understand the processes or the capabilities of his machine. Case in point, when someone tells me the weld for a living, everyday then says something like "Heli-arced", that tells me they aren't as familiar as they think they may be.

OTHO, when I hear...


That says to me the person that wrote that has been welding for a while and is indeed familiar with the processes and capabilities of the various machines.

Or someone who read a book and knows the tech side.

I've seen and heard both ends of that coin not only from welding but in the computer world as well. Often times those people scare me more that-is until you have a conversation with them more than once, and they can prove they know a bit more than what the book says

[vegasloki]

Originally Posted by Todd W

Or someone who read a book and knows the tech side.

Do you weld? You wouldn't get that deep into it just by book knowledge. That is serious industrial welding, ugly, boring and mundane. To me, anyway. Look at the other aspects of his posts. He knows Ohms Law and that the difference in voltages at a given current. That's important for machine output. How do I konw? I was taught in a lecture. Then we went out into an AWS accredited learning facility to practice. And practice. And practice.

"Mad Machinist" doesn't know his processes or his machine limitations for a nominal 120 volt unit. He has not shown in this thread he understands the relationship between output voltage and current for a given input voltage and current. Though he may weld all the time, he doesn't understand how the mechanics of the machines work. There is a reason that most applications like that, mining is a good example, use generator sources and wire feeders. A 120 volt machine is indeed handy for some apps but it's no replacement for all welders.

[thesk8nmidget]

i used to work for road armor and did all the cad drawings for the bumpers, which are the same as the one you posted, when we designed them we would start with a premade center section from a similar size truck, then we would used hard card stock and work our way out from the middle. once that was done we would cut the pieces out using a plasma, then weld it all together, then i would put that all into solid works for mass production.

i wish i still had the files to make some for myself.