Car alternators for welding power source ?

[Waterworks]

Is it theoretically possible to build a serious welder generator using multiple car alternators?

Why? Well they are cheap as chips and so are small engines, while welding generators are very expensive. I have multiple small engines and alternators in my junk pile right here.

How would amps output be regulated?

How would you achieve a serious OCV?

[rexcormack]

The first issue is most car alternators only put out about 60 amps max intermittent duty.
There are some engine mounted alternators designed for welding but they are very expensive and
still don't do that great a job.
The off road guys know all about this.

[LameNRG]

I think you could make this work; I have contemplated making not so much a welder but a homemade generator. I would think that with an Ambulance alternator, a battery bank, and a large inverter you could do it. However, with the cost of all of that, a prebuilt generator might do you better.

Something like this:

But bigger.

[Sberry]

I saw one that works pretty well. No idea how long it might last.

[jpump5]

There’s several videos of homemade alternator welders that
seem to work pretty well. There’s even a guy that built a
scratch start tig with foot pedal using an electric motor to
spin the alternator. One of the companies that sells alternator
based welders claims that the “ high frequency DC” makes for
a better arc. I was considering building one myself and salvaged
a high amperage truck alternator but decided against it.

[tapwelder]

Yes. You can do it.

There are multiple threads on this forum concerning this. I used to own a commercial under hood welder, it piggybacked off my generator and had idle control. It needed about 6000 rpm’s. Achieved through pulley sizing. Biggest issue was belt wrap. Incredible torque was needed for welding so two pulleys was not ideal, needed an idler. Emits an annoying HF whistle, however so does my HTP221.

Mine was ZENA. Biggest negatives with on board installation was custom bracketing, engine repair access and changing over for different vehicles. Also clearance inside the compartment.

[Sberry]

Ya, at first thought that looked like an ok idea but agree,,, wayyyy to complicated. Like PTO air comp and all that st5uff hooked to the engine. When it worked it worked ok but a lot of fussy stuff to go wrong. I remember in about 2008 they claimed to be on the verge of power gen on pickup trucks,,,, seems that idea may be making a comeback and for the serious worker thats not all that huge cost especially when we are now going to be able to add a low cost welder to it.

[SweetMK]

The ZENA welder must be over 25 years old,, I remember when I first saw the literature.

https://www.zena.net/htdocs/welders/weldspec2.shtml#Top

Just spin it, and weld,, the price is very reasonable compared to many engine welders,,
of course, the engine is supplied by you,,,,,,,,,,,

[52 Ford]

The ZENA welder must be over 25 years old,, I remember when I first saw the literature.

https://www.zena.net/htdocs/welders/weldspec2.shtml#Top

Just spin it, and weld,, the price is very reasonable compared to many engine welders,,
of course, the engine is supplied by you,,,,,,,,,,,

Mount one of those on your truck with a clutched pulley on it. That'd be pretty nice.

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[jpump5]

That current control and hot start button on the Zena
electrode holder looks pretty slick. Not sure how useful
it really is or how well it holds up.

[CAVEMANN]

I think you could make this work; I have contemplated making not so much a welder but a homemade generator. I would think that with an Ambulance alternator, a battery bank, and a large inverter you could do it. However, with the cost of all of that, a prebuilt generator might do you better.

Something like this:

But bigger.

With the advent of LED's Ambulance alternators are no longer the old massive Leece-Neville units that were always cobbled on with a bunch of stuff trying to make it line up & fit properly, starting in about 2001 Ambulances began using factory dual alternators of about 130 amps each, the second alternator or "auxilliary" unit was controlled by the ECM as extra amps were needed, I had a supplier in central Phoenix that supplied all my electrical and Turbocharger needs, he was a Leece-Neville guru and loved them, but he even admitted to me that the factory setup duals were much more reliable, 97 Fords E bodies with the ambo package had a Mitsubishi 230 amp unit that was good, it was also expensive. Cop cars also had massive alternators in the day.

[52 Ford]

With the advent of LED's Ambulance alternators are no longer the old massive Leece-Neville units that were always cobbled on with a bunch of stuff trying to make it line up & fit properly, starting in about 2001 Ambulances began using factory dual alternators of about 130 amps each, the second alternator or "auxilliary" unit was controlled by the ECM as extra amps were needed, I had a supplier in central Phoenix that supplied all my electrical and Turbocharger needs, he was a Leece-Neville guru and loved them, but he even admitted to me that the factory setup duals were much more reliable, 97 Fords E bodies with the ambo package had a Mitsubishi 230 amp unit that was good, it was also expensive. Cop cars also had massive alternators in the day.

You can still get 400 amp alternator packages on Ford Super Duty trucks. I think I've seen a 600 amp option on Ram trucks.

Snowplow prep packages usually high the high output setups

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[52 Ford]

On the Super Duty Fords, it's 240 and a 157 amp dual alternator setup.

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[52 Ford]

And Ram offers dual 220A units.

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[nickel_city_fab]

I thought about this briefly and decided the way to regulate the welder is to vary the field with a rheostat. And yes, they need high RPM's to be useful. I could see a TIG rig with a generic 12SI 140-amp alternator, or maybe for 3/32 stick.

[N55_6MT]

There are off road welding power sources that do exactly this.

Premier Power Welder, LLC

I'm not sure exactly what's so special about their "hand-wound" alternators, but I've got a buddy with one and he's said it works OK in a pinch. Not sure you'd want to roll your own without some good electrical knowhow.