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Author Topic: Welder  (Read 550 times)

mikenash

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Welder
« on: August 24, 2019, 11:32:14 AM »
I wonder if anyone has built a welder powered by a CS or similar using a Lincoln Tractapak or Hummel or PTO-drive welder unit?

I dunno if 6HP would cut it - but these old girls have a surprising amount of torque and might manage, say, 150A?

I'd be interested in any thoughts.  Cheers

ajaffa1

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Re: Welder
« Reply #1 on: August 24, 2019, 12:02:27 PM »
Hi Mikenash,  No I have not tried this, however, many years ago I used to use a very old trailer mounted Lincoln welder it had a single cylinder diesel and belched smoke under load but it did weld well. It could also be used as a 240 volt generator. I think the important thing to consider is that my old Lincoln welder was close coupled to the old generating/welding equipment. I wonder if a belt driven unit off a CS might have too much belt slip and voltage variation make welding an exciting/difficult activity.

Bob

oldgoat

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Re: Welder
« Reply #2 on: August 24, 2019, 02:49:43 PM »
I think you might need a bit more hp than a CS has got because the welding generators seem to run about 1800 rpm. You might get enough output to tun a 12 gauge rod but that is about all. My Lincoln has a perkins 3-152 but it is 400 amps max. The perkins is about 40 hp I think.

BruceM

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Re: Welder
« Reply #3 on: August 24, 2019, 03:50:47 PM »
I concur with oldgoat.

For my battery welder, I recently measured stick welding voltage at between 24 and 28 V at the electrode, for 3/32 to 5/32 rods for up to say 220 amps.  The higher end of that is over 6000 watts so the CS isn't going to make it.  At the low end, 3/32 rods and say 25V/100A  (2500W actual, before wire/cable losses) the CS 6/1 isn't quite going to to make it.  Some propane in the intake might help.  An 8/1 might do 1/8 rods.

As for a direct driven setup I'm not sure how the 10Hz power pulse frequency/voltage sag will affect arc stability.  Given the  low cost, small size and efficiency of modern switch mode DC stick welders, I wouldn't bother with a directly driven welder.

My 30V battery welder is working nicely for me.
 
http://listerengine.com/smf/index.php?topic=8654.msg101247#msg101247

It gives me the needed peak power but lets me charge it at a slower rate off my PV/inverter system.  My neighbor did welding on about 26 fence posts a couple days ago with it.  That did not deeply discharge it and in an hour of charging at 15A they were nearly full. This was tack welding with zinc removal via air grinder, so low duty cycle.  From my own work I know 7 rods doesn't faze it much, so for repairs and small projects I see no issue.  I'm thinking of building a carry all for my tractor's 3pt hitch which would let me roll the battery welder up onto the carry all and then strap it securely to the back of the carry all for field work.  With three batteries, it's hefty. 
« Last Edit: August 24, 2019, 03:55:12 PM by BruceM »

mikenash

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Re: Welder
« Reply #4 on: August 25, 2019, 04:38:15 AM »
Hi guys, sure.  I sort of have a handle on that - if the Tractapak runs at maybe 32VDC then, say, 250A is (32 X 250 X 120% for losses) = something like 13HP nominal

I have a 13HP chinese genset & it runs the 220A welder OK.  But the welder makes funny noises - because it doesn't like the ugly square-wave power I would guess

And I know when I have hired large single-phase petrol gensets from local hire companies that they say "You're not allowed to use this to run a welder, it'll wreck it".  The only reason I ever hire a genset is to run the welder just in case it decides to wreck it - better than wrecking mine . . .  They want you to hire the trailer-ised diesel genset or generator-welder; but it'd be cheaper to pay a mobile welding man to come do the job . . .

Anyway . . . it's all very well to talk about 220A, 250A.  What are we doing, building bloody bridges with 4mm iron-powder rods?  Mostly we're doing shit like repairing the trailer, or making a frame for a 'Roid out of 10mm RSJ & plate.  The former is either 3.2mm rods at 90A or, more likely, 2.5mm rods at 70A.  The latter maybe 3.2mm rods at 130A

And, anyone who spends a few hours looking through a welding helmet knows that, if you have to, you can repair/build most anything with multiple runs of light rods - AS LONG AS YOUR PREP IS GOOD

mikenash

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Re: Welder
« Reply #5 on: August 25, 2019, 05:03:31 AM »
Hi guys, sure.  I sort of have a handle on that - if the Tractapak runs at maybe 32VDC then, say, 250A is (32 X 250 X 120% for losses) = something like 13HP nominal

I have a 13HP chinese genset & it runs the 220A welder OK.  But the welder makes funny noises - because it doesn't like the ugly square-wave power I would guess

And I know when I have hired large single-phase petrol gensets from local hire companies that they say "You're not allowed to use this to run a welder, it'll wreck it".  Except they don't say "wreck".  Now, the only reason I ever hire a genset is to run the welder just in case it decides to wreck it - better than wrecking mine . . .  They want you to hire the trailer-ised diesel genset or generator-welder; but it'd be cheaper to pay a mobile welding man to come do the job . . .

Anyway . . . it's all very well to talk about 220A, 250A.  What are we doing here, building bloody bridges with 4mm iron-powder rods?  Mostly we're doing shit like repairing the trailer, or making a frame for a 'Roid out of 10mm RSJ & plate.  The former is either 3.2mm rods at 90A or, more likely, 2.5mm rods at 70A.  The latter maybe 3.2mm rods at 130A

And, as anyone who spends a few hours looking through a welding helmet knows that, if you have to, you can repair/build most anything with multiple runs of light rods - AS LONG AS YOUR PREP IS GOOD - as every welding instructor will SHOUT at you over and over.  Sure you'll do stuff like leaving a small burn-through gap between initial set-up components, and turning stuff over so that you can always do your weld slightly uphill to better manage the puddle, and using 7018s - which you should be anyway . . .  All of those things are good practise anyway

In an "off grid" situation where you have a 6HP diesel sitting doing nothing, and where there's room on its frame to mount some sort of DC head . . .

So, if you had some DC device that ran at, say, 25VDC, and you accepted that you'd end up using 2.5mm rods at, say 80A - all of a sudden it's:

25 X 80 X 1.2 = 2.4kW

Just kicking it around really.  I'm gonna keep an eye on TradeMe for old PTO-drive type heads.  Who knows, I might find an abandoned Miller or Licoln diesel one cheap anyway?

Cheers

BruceM

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Re: Welder
« Reply #6 on: August 25, 2019, 06:26:25 AM »
Yep, on small rods you should be able to do it.  A trickle of propane in the intake does clean up the exhaust on a moderate overload (I've tried it), and does nothing but good for the engine.  Alas, unlike methane, it can only replace about 20% of the fuel (max).

For an Ufer grounding system at my house I had all my rebar tack welded together and my helper used his small flux core MIG rig on my 4000/4500 (peak) Watt cheapo gas backup generator.  No troubles, though he did jack up the rpm a bit which helped with the surge load greatly.   So a modest MIG rig might be a good lower power welding choice.  They are fixed voltage, from low to high 20's volts. I'd guess 70-90A.  CS 6/1 territory.

I would guess your welding rig is not great power factor, which is why the generator is stressed.  Waveform is irrelevant to the welder, which would likely saw the top off of the nicest sine. Welders stress generators because the poor PF and big surge loads means guys are often trying to run over the capacity of the electronics, which were rated with the wild optimism of marketing fairy dust.  The standard modern practice of grossly oversizing the genhead on CS engines should solve that.  The other issue is that welders generate massive EMI- lots of nasty spikes on the power, which may fry an AVR.  A cheap commercial power filter (dual stage CM choke and small caps) would likely stop that.

I decided not to try a battery DC MIG setup because of a couple reliable sources of welding literature  stated there is a strong AC interruption of current (5-100Hz) when using the normal MIG shorted wire welding method. The wire extends into the puddle, shorts out, melts off a blob, open circuit, repeats as the wire is fed. Frequency depends on set voltage and wire feed rate. It's the source of the frying bacon sound of MIG.  I thought that would be a bust, health-wise for me.  It helped explain why I have to stand back a LONG way from MIG welders.

A CS based welder is most interesting project.  A guy who thinks- "hey, I think can do what I need with less power" is well suited to practical off grid living. 









« Last Edit: August 25, 2019, 06:42:15 AM by BruceM »

mikenash

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Re: Welder
« Reply #7 on: August 25, 2019, 08:59:21 AM »
Hi again Bruce

See link?

https://www.trademe.co.nz/business-farming-industry/industrial/manufacturing-metalwork/welders/listing-2286611569.htm?gclid=CjwKCAjw44jrBRAHEiwAZ9igKPI02lL3j7TSYNqgnOtuedtdw50aanM8AlGSOFfpMhhfoPK0_1SpFBoCxToQAvD_BwE&gclsrc=aw.ds

The single-phase welder I use for everything is a close cousin of this - couldn't find the exact one, but it'll be functionally identical

They're cheap, about $400.  I first bought one maybe 15 years ago when the expensive $2500 Italian unit I was using blew up for the second time (first time repair bill was $1500).  I get four or five years out of them (I'm on my third)  They're super-portable and have enough of a duty cycle (80%-odd maybe? I forget) that the downtime between electrodes for scraping, wire-brushing, occasional grinding and, of course, swapping rods is enough to make the duty cycle effectively 100%

I once built a big steel frame in the sawmill out of 12mm wall 150 X 160 SHS (half-inch wall, six-inch square tube)  and,once it was all tacked up, spent maybe four hours burning a packet of 4mm rods - you might call them 5/32"? maybe - to stick it all together.  My hands overalls & gloves were smoking and every bit of my beard that stuck out anywhere outside my mask was frazzled off - but the welder didn't give a toss.  I still got another couple years service out of it . . .

So they're cheap.  But not nasty

But for some reason, when you run it off the generator, it makes an odd noise.  Kind of a whine?  hard to describe.  I don't have any way of knowing if it's bad for it and I don't much care cos if it dies the boss will just buy me a new one

Anyway,  that was the basis for my ill-informed assumption that maybe it didn't like the non-sine wave

Re off-grid?  Yes, I have always been "less is more" with woodstoves, LPG hobs, wetbacks, solar hot water, gravity-generated water pressure . . . all that stuff

I just planted 100 coppicing gum trees near my shed so I can have close, convenient firewood (think chainsaw + wheelbarrow lol)

Just cos I'm gonna be broke in retirement doesn't mean I'm gonna be miserable lol

Cheers

dieselspanner

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Re: Welder
« Reply #8 on: August 25, 2019, 09:36:21 AM »
Two great quotes in the last two posts.....

A guy who thinks- "hey, I think can do what I need with less power" is well suited to practical off grid living. 

Just cos I'm gonna be broke in retirement doesn't mean I'm gonna be miserable lol.

Sums up exactly where my (and, I'm certain lots more guys on here) head is at!

Cheers
Stef
Tighten 'til it strips, weld nut to chassis, peen stud, adjust with angle grinder.

ajaffa1

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Re: Welder
« Reply #9 on: August 25, 2019, 10:43:26 AM »
Hi Stef, when I am broke after a lifetime of work and paying taxes and etc on the promise of a pension in my old age, I plan to shoot a politician of my choice for having lied to me and stolen my money. I then plan to surrender myself to the authorities, they will try me for murder, to which I will plead guilty. I will then spend the rest of my days in prison where I will have a roof over my head, three good meals a day, air conditioning and all that free health care that is not available to the average civilian. This plan also comes with free internet access, education, television and treatment for depression (free happy pills).

Australian prisons now have a total no smoking ban, which caused terrible problems when it was implemented. As a lifelong smoker the first few weeks could be difficult , however I like the idea of a thirty year jail sentence that starts with me having to quit smoking. This will probably extend my life expectancy considerably and cost the government hundreds of dollars a day for as long as I can keep going.

If after many years of this comfortable retirement plan the parole board decide to release me back into society, I plan to go and shoot another useless politician of my choice.

Bob

glort

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Re: Welder
« Reply #10 on: August 25, 2019, 01:54:01 PM »

Water/ methanol injection is a lot easier on engines than LPG to get more power.
« Last Edit: August 26, 2019, 03:58:16 AM by glort »

BruceM

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Re: Welder
« Reply #11 on: August 25, 2019, 05:11:35 PM »
This was an interesting and enjoyable thread on welder and welding tech and very positive self help now gone to threats of murder and derision of people who want to reduce racist mass murders.  I'm just going to speak out and say please stop.  I'm not well myself so I understand depression, anger, loss, pain and misery and being marginalized.  I'd be very grateful if this forum could be a positive place.

sirpedrosa

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Re: Welder
« Reply #12 on: August 26, 2019, 12:03:37 AM »
Hi Everyone

I am self-taught in welding, that is, if it looks good in the first run I do not need to grind, if it does not go well, grind it and put a second run.

But, of course, to make a welding worthy of the name, I still have to burn a lot of welding rods. As many of us (excuse me if i'm wrong) at this days you must  have a cheap 120A inverter to do light job on shop. MIG's and TIG's are other championship (yet for me).

Giving a hand to Bob: What can I do to divert you from that ideas of shooting liars. There will be a dozen of others waiting for it's velvet seat chair. Sorry if I'm saying, or said, something that disregards you!

You don't need to go to jail to quit smoking. Just exchange it to a bootle of the same price and have to last the same time as the packet.

I stopped burning them in 5out90, and I still have the empty packet with lighter in it. It was a packet a day - if I slept - otherwise it was almost two.

Have all of you a safe week
VP

Ps: I also feel marginalized, no longer reminds me why, but I have this feeling.
Bernard 18A - 1968 (mama's water pump - year of my birth)
Petter PAZ1 - Jun 1967, 3HP, sn 416xxxx
Petter PAZ1 - Nov 1979, 3HP, sn 425xxxx

mikenash

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Re: Welder
« Reply #13 on: August 26, 2019, 07:43:22 AM »
Hi Bruce

I'm sorry that light-hearted stuff has caused you distress

As an American It might be hard for you to understand antipodean humour?

That comment was an example of the black humour common in NZ and Australia, and the joke about shooting a politician or two to gain oneself a warm retirement with healthcare etc . . . . it's a bit hard to explain but it's an old, old, joke

It has nothing to do with shooting politicians, it's a commentary on the way politicians run things so that a working man, having toiled all his life, and now in his twilight years, cannot afford healthcare, or to get his rotten teeth fixed, or his worn-out hip replaced, or somewhere warm and dry and safe to live with central heating and three square meals a day, or even somewhere warm, dry and vaguely hospitable where he might feel comfortable having his grandkids visit . . .

Whereas a criminal, never having done an honest day's work in his life, is rewarded - by said politicians - with the tenure of a warm dry cell, with three square meals a day, an out-of-the-weather exercise yard, first-world health & dental care, free clothing. bedding, laundry, library service, TV etc etc, plus visiting rights for his family, the prospect of government assistance to allow them to move house to be closer to him so as to support and visit him, and the congenial company of like-minded others

Since all one has to do to move from private poverty to government-funded luxury is to commit a substantial crime - then the politician (the cause of the problem in the first place) is an ideal target

That's the short version lol

ajaffa1

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Re: Welder
« Reply #14 on: August 26, 2019, 12:21:24 PM »
Hi BruceM, I apologize unreservedly if I caused you offense. I would like to point out that I was only joking and have no murderous intentions. As an ex military person, trained to kill people, I can honestly say that there is no blood on my hands, nor do I intend there to be.

Thank you Mike and VP for standing in my corner and trying to explain Australian humor. Bruce and I are more than able to sort this out in a civilized and adult fashion, perhaps he is right in suggesting we stick to topic and stop getting sidetracked. I disagree, but am willing to accept his criticism.

So back to welding using a Lister CS as the primary mover. In my limited experience, I have always found that welding using any sort of generator setup is problematic because of the sudden load when striking the arc and the lag associated with the governor mechanism trying to deliver more fuel to counter that sudden load. I have seen and experienced no end of invertor welder failures when connected to slow responding petrol generators. My Lister ST2 startomatic produces 7KVA but struggles to keep up with any welder I have used with it. That said if I load up this generator with the motors for my surfacer and thicknesser, it improves thing enormously. Back EMF and extra mass, I guess.

I believe that a CS driving a 48 volt alternator charging a 48 volt battery setup would provide a very satisfactory welder as the batteries would reduce the sudden load effect, allowing the governor to catch up. That said, modern batteries do not go well with high loads for extended periods, so you would need a large battery pack. Probably cheaper to look for a second hand Lincoln welder.

Bob