How about a project of the month? On-Board welder question.....help my XJ

mbryson

.......a few dollars more
Supporting Member
Let's make this some kind of point of interest? Hopefully this is a topic for everybody. I for one haven't spent much time visiting this area......what do we want to see here? I can talk about XJ's all day long, but that wouldn't be too interesting for you 'Yota types......If it works on my XJ it will easily work on almost anything non-computer controlled and probably most computer controlled {you are at your own risk there}


This is kind of fictional, but I've been wanting to add an on-board to my XJ. Seems like it will be about $1K for a packaged solution (give or take $200-300), but has anybody done a 'home-grown' deal?

Suggestions?

I know I can call Mobi-Arc or Premier, but has anyone BUILT ONE on an HO 4.0L without frying the electronics? If we can come up with a plausible solution, I'll do it.
 

Ryan

Registered User
There are a few options in this article.

http://www.pirate4x4.com/tech/on-boardwelder/index.html

All of them are relatively cheap, but you can't beat this set-up for DIRT cheap:

Welder "option two": If you have a GM alternator and don't want to change over to a Ford, here's what you can do. You can mount the Ford alternator separately and not even hassle with wiring into your charging system. If you do not have an extra pully to run the belt off of, you can weld another pulley to your primary alternators pully and run off of that. I suggest that you mount the alternator, but leave the belt disconnected when not in use. If you do not have room for a second alternator you can simply mount it to your fender well or something. It's not like it will be hooked up all the time, so it should be just fine. With this system you do not need the power converter box, but may want it for the convenience of the power outlets and such. You only need a power wire from the battery to the field post of the alternator to energize it. I suggest you put a on/off switch in between the alternator and battery. Then run a heavy 4 gauge cable off the output terminal of the alternator for your stinger. That's the very simple way to use a alternator as a welder, it's simple, plain, but works as well as the other type I explained.


I had planned to do this on the Cruiser, but it's no longer in my possession.
 

mbryson

.......a few dollars more
Supporting Member
All righty.....so we are talking like $150 or so for the Ford alternator (maybe less), some kind of bracketry work, and some electrical leads to actually weld with, eh?
 

Ryan

Registered User
Originally posted by mbryson
All righty.....so we are talking like $150 or so for the Ford alternator (maybe less), some kind of bracketry work, and some electrical leads to actually weld with, eh?

That's about the way I see it. I called a few junk yards on the alternator when I was looking into it before. I don't remember who I go the info from, but I guess there's a small case externally regulated Ford alternator and a larger case one. I may be way off on this(it's been a year or so), but I think the small one was like 60 amp, and the larger one was around 90 or so. The larger case alternator was a shelf item at Kurts in AF(and most likely other yards as well), and I think they wanted like $60. A hand throttle would probably not be a bad idea, but a friends foot on the gas would be just about as good. I don't wheel my wifes Runner enough to mess with it now, and besides, I don't think you could even fit a frickin' toothpic under the hood with the 3VZE.

It's a little more work and money to add the outlet option, but I could see it coming in handy.

Also, in a pinch jumper cables could be used in place of leads.
 
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RockMonkey

Suddenly Enthusiastic
Did you build this yet, Marc? I wanna strike an arc on one and see if I can actually weld with it, then I'll build one myself. By the way, you can get dual groove pulley's from http://www.onboardair.com to run a second belt from your alternator on your 4.0.
 

mbryson

.......a few dollars more
Supporting Member
I haven't built it yet, but I did have the opportunity to use a Mobi-Arc unit a while ago. They work quite well. That is a 'must-have', probably before I work on the on-board air {I seem to run around with people that run Yorks, and I've always got the ulta-cool, ultra-speedy ARB compressor in a pinch--it'll fill up one 35" tire per hour}. I've been having enough problems keeping mine running lately, that I've used up ANY mod money on that and won't have any for a little while.

The bead on my axle u-joint was welded with the Mobi-Arc, if you want to take a look at it. Brent welded it, and it's a pretty decent, clean weld.
 

cruiseroutfit

Cruizah!
Moderator
Vendor
Location
Sandy, Ut
I'm also interested in various ways to add an on-board welder. I've looked intot he Ford alt. option a while back but I never followed up on it. I'm looking forward to hearing reports of how one of you guys did it.... :D
 

RockMonkey

Suddenly Enthusiastic
I know the spendy off the shelf units make good welds, I want to see something welded with a Ghetto fabbed up home built jobbie.
 

RockMonkey

Suddenly Enthusiastic
Very nice writeup, and very nice execution of the project. When I look at the pick-n-pull for an alternator for this project, how do I know which ones have the diodes built in, and put out DC current, as opposed to those that put out AC? It just looks so easy... Do you have a background in electrical engineering?
 
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Jeeplvr

Back to formula!
Location
Reno NV
My electrical experience comes from on the job training and college courses taken in the past.
You will be looking for an alternator that is externally regulated. Fords and Chryslers or Dodges are externally regulated and should have a diode trio in them.
Anything from the 70's or 80's should be this way.
If I am mistaken, someone please feel free to post a correction.

Most Chevy Delco alternators are internally regulated. In my experience, Ford or Chrysler alternators are very easy to make welders out of.
Of course there are the Leece Neville alternators and many others that are good as well but are harder to find.
My Chrysler alternators were in Taxi's. The general everyday Chrysler doesn't have an alternator this size.
I have seen welders made from 100 amp Delco's (Chevy) and 100 amp Motorola’s (Ford) but they usually aren’t built as heavy as the larger amp rated alternators and will overheat easily. You can build a welder from a 70 amp alternator but you wont be able to burn a very big rod.
Unless the diode trio is in the regulator, the alternator has to have it internally. Usually it is in the windings of the stator.

Here’s a link to an OBW made from a Delco internally regulated alternator, which are plentiful in the yards.
http://www.huv.com/jon/jeep/Welder/on-board-welder.html
 

cruiseroutfit

Cruizah!
Moderator
Vendor
Location
Sandy, Ut
Cool! add one more item to my winter list of stuff to do. Anyone run one of those wire-feed units? I assume you can use your rigged up alternator as the power source rather than buying a mobile welder or such...Any ideas?
 

OCNORB

Well-Known Member
Supporting Member
Location
Alpine
I have a home-brewed welder on my Bronco- saved us last year in Cedar when one of the other Broncos on the trail run busted up his steering linkage. Mine is similiar,but simpler than jeeplvr's setup. I found an alternator at PnP- Ford externally regulated 120 amp- (took some lookin and some luck-looked like an old cop car) .I mounted the second alternator where the smog pump used to be. I used a 20 amp relay to charge the field and a hand throttle control with stop(vice grips for now) to regulate it. The power lead and relay are mounted in a Radio Shack box under the hood. It's pretty simple to do this way and works well enough for trail repairs. I've used it to do little welding on the Bronco, but it really is best for emergencies.
 

Dracsnar

Dracsnar the Necromancer
Location
south east idaho
just read through this and found some good stuff, now when i get the truck on all fours, and the rest of the little things done i think i will bould me an on-board system :cool:
 

mbryson

.......a few dollars more
Supporting Member
just read through this and found some good stuff, now when i get the truck on all fours, and the rest of the little things done i think i will bould me an on-board system :cool:

Yell when you are ready. I have a different rig now and it's BEGGING for OBW. There's a lonely bracket hanging there and everything ('89 truck TBI 350).
 

cruiseroutfit

Cruizah!
Moderator
Vendor
Location
Sandy, Ut
I'm still psuedo interested... I ended up with a Ready-Welder setup.

For $600 it made sense for me. I can use it anywhere I have batteries, not just near the rig its mounted on. I have a couple of wheeling rigs, so I can take it in the one I'm wheeling in. Also, I doubt I have any room under the hood of my Tacoma or FJ62 for another alternator.

I'm still interested in seeing how this all goes together... somebody needs to rig one up :D
 
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