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alternator welder write up

44K views 140 replies 19 participants last post by  88dually 
#1 ·
so hopefully im putting this in the correct area... but here it goes, i was asked to do a write up of my alternator powered welder on my jeep.

i apologize ahead of time if its difficult to follow this is my first write up

things you'll need
1. alternator (must be externally regulated, such as the ford alternators.) i used one out of a 1981 cougar with the 5.8l v8. its best if the output of the alternator is 70+ amps mines 110 amps
2. some thick gauge wire (2 or 4) will work
3. some thinner wire. just to excite the alternator (must be detachable, you dont want to leave plugged in while not in use)
4. a way to mount the alternator in your engine bay (home made brackets work)
5. extra pulley (or if you can bolt it on your belt where it fits thats great too)
6. belt (once again not needed if it fits somewhere on your stock belt)
7. a stinger to hold the welding rod (or you could use jumper cables, stinger is best)
8. a way to adjust engine rpms without pedal.

i know it sounds like a lot but really its not as much as it sounds. i dont have pictures of me installing it but i have them of it finished so ill try to walk you through it

this picture shows the mount that holds the alternator on the frame, it was made from metal that i had laying around. i cut 2 right angles out of it, welded them onto the frame 3 inches apart, drilled holes in em and mounted the alternator on top.



since my system is used only when needed i made things easy to disconnect. alternators become more difficult to turn when you draw power from them, and since welding takes quite a bit of power you'll need a way to tighten the belt so the alternator doesnt slip, i used a ratchet strap hooked on to my frame on one side and the other end on a bolt going through the alternator.



you'll have to excuse my wiring (the v8 swap isnt fully completed) but the red wire up on top here goes directly from the battery's positive to the field terminal on the alternator




the red and black wires coming of the alternator will be your direct ground and positive. obviously black is ground and red will go to your stinger.


this is a bad picture but you can see where that red and black wire lead. the front of the grill where i clip my leads onto.


and there you have it. your alternator welder is complete. time to try it out.

the way i have things work is i use a set of jumper cables clipped onto those wires coming off the alternator, then i clip the positive of the jumper cable to my stinger and the negative continues to be the ground.

heres a quick video of it working. please i dont need a lecture on proper welding equipment, i made the video spur of the moment and didnt have my gloves/mask with me. and yes my eyes were closed i just wanted to show that it works.

 
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#2 ·
Good deal
 
#6 ·
there is a way to do it using the stock alternator. still has to be externally regulated though. but you get a 110v regulator from autozone with a switch and you can switch it from powering your jeep to being a welder.
 
#8 ·
thanks, its just a flowmaster 44 clamped onto flexible pipe until i get my c6 headers in the mail :2thumbsup:
 
#5 ·
I like it... something I've wanted to do for a *long* time!

Just in case you'd like to know... big diesel truck alts are the best for this, I mean mack and freightliner, thermo-king refrigerator trucks, etc. Reason being most of them are 24-volt instead of 12 volt. Also, it takes about 120 amps to burn 1/8 inch rod. Regular welding machines (good ones) will keep about 28 volts at whatever amps you put.

Obviously the ford alt worked, and its lo-buck cheap-n-easy mod! I love it!
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#7 ·
thanks for the tip, ill look into that once this alternator burns out (made in china) the way i have it mounted i can easily switch whatever i want into it. at idle the alternator is outputting 34 volts though so its doing fairly well, i did a test a few days ago at 5000rpms just to see and it was right around 213 volts. so at about 3000rpms i can actually run grinders and tools like that off of it. as long as the motor has brushes
 
#9 ·
a question though, with a 24 volt alternator would that mean id have to supply the field terminal with 24 volts instead of 12? im planning on running dual batteries so i could figure out a way to give it 24 if i had to, just wondering
 
#13 ·
If you want to use both pullys on your alt, try finding an older chevy or GMC straight 6 cylinder at a junkyard. From the 1960's or 1970's. Double pulleys were standard on them. You could stack one of them on top of your regular crank pulley. That way you won't have to winch on your alt so hard to keep it from slipping. :thumbsup:

The machine I used at work was just a regular construction site welder, big blue box with a muffler on a trailer.
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only problem is the pulleys are different sizes on the alternator, inner one is deeper so id need to have a way to offset the difference in pulley size. the first time i tried it i figured i had enough tension just having it bolted in and it killed the belt in like 5 seconds. i didnt know much about alternators so i didnt think it could be that hard to turn... so very wrong :brickwall
 
#15 ·
only problem is the pulleys are different sizes on the alternator, inner one is deeper so id need to have a way to offset the difference in pulley size. the first time i tried it i figured i had enough tension just having it bolted in and it killed the belt in like 5 seconds. i didnt know much about alternators so i didnt think it could be that hard to turn... so very wrong :brickwall
:eyebulge: that's weird, never heard of diff size pulleys before... OTOH I think the shaft on car alts is a standard sizes for all of them, if I remember... maybe there's a different one you could swap on?
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#14 ·
i think ill be good with the hobart in the garage for awhile before ill require a $13,000 welder lol. i can imagine it'd be pretty fun using it though
 
#16 ·
btw did i mention that this mod costs less than 150 bucks if you can get your hands on a used alt, and a cheap stinger. my stinger was free, we have a broken chicago electric welder in my dads garage so i took the stinger from
 
#17 ·
That's what I like the most about it. The junkyards around here only want $40 for the alt regardless what kind. Which is cool because that's all my budget is :laugh:

But seriously I wish I had seen somebody do this *years* ago, I coulda been making $$$ on the side that way.
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#25 ·
#28 ·
ill just hope my rig isnt the one that is breaking, thats the best plan lol
 
#30 ·
thats awesome, it took me a minute to figure out how a motor would mount on it. i need to find a winch before it snows here too...
 
#37 ·
post up when you do, ill be interested to see what you do with yours. i kinda pulled my design outta my *** so theres a lot of improvements that can be made
 
#38 ·
yea its 100% duty cycle so you can weld as long as you still have more rods. with someone who is actually a good stick welder im sure it'd do very well, i mostly do mig so im still learning stick but from what ive seen the welds it puts down will hold just as well
 
#41 ·
btw to anyone else planning on doing this make sure you disconnect your field wire, it will drain your battery over night... found that out last week
 
#42 ·
Could always just put a switch there. I had an idea to mount a switch on the stinger itself, and just use jacks to plug the whole thing in thru the grille... kinda like those HD connectors on tow trucks.
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#43 ·
im waiting for a set of plugs to come on sale from harbor freight so i dont have to clip leads on em anymore lol. i was gonna put a switch in but i didnt have one laying around so im just using a knife connector for now.
 
#46 ·
it seems like more than it really is, i set it up in a few hours after school one day
 
#47 ·
Ripper3494 said:
it seems like more than it really is, i set it up in a few hours after school one day
I think iv bout got my dad talked into it. Just gotta find a alt at the JY gonna get one off of a truck that had all the bells and whistles
 
#48 ·
make sure you get one thats externally regulated, unless you wanna do some internal mods on it, thats why the ford ones are nice
 
#49 ·
Ripper3494 said:
make sure you get one thats externally regulated, unless you wanna do some internal mods on it, thats why the ford ones are nice
Why externally regulated? Iv put alts on but never got technical with one
 
#50 ·
the regulator limits the alt to approx 14 volts, as to not blow up a battery, when the regulator isn't attached you let the alt output all it is capable of, and in my case is approx 213 volts at the highest rpm im willing to run it at for an extended time. 36 volts at idle
 
#52 ·
not exactly my idea, didnt invent it, but hey ill take the credit :highfive:
 
#53 ·
Ripper3494 said:
the regulator limits the alt to approx 14 volts, as to not blow up a battery, when the regulator isn't attached you let the alt output all it is capable of, and in my case is approx 213 volts at the highest rpm im willing to run it at for an extended time. 36 volts at idle
And back to ford
 
#54 ·
it can be done with others, you just need to know what your doing (which i dont) so ford is the route i took
 
#55 ·
Could one potentially learn the basics to welding with this thing?
 
#57 ·
yep, works like any other stick welder, only difference is its 100% duty cycle so you can weld non stop till you run out of gas on the jeep
 
#58 ·
to be completely honest it works far better than the stick welders at harbor freight ive used, not gonna lie i still like my 220 mig a bit better tho lol
 
#59 ·
Ripper3494 said:
to be completely honest it works far better than the stick welders at harbor freight ive used, not gonna lie i still like my 220 mig a bit better tho lol
I like the stick better. Just something bout that little wire don't seam trust worthy
 
#61 ·
first time i welded up my anti wrap bar on my jeep i had my angles wrong, so it actually held the entire rear end of the jeep at full droop with the tires on the ground, welded it with flux core because i ran out of solid and it actually held, i have full trust in mig welders for anything youll put on a jeep, i wouldnt trust mig on something like construction equipment though
 
#63 ·
Ripper3494 said:
first time i welded up my anti wrap bar on my jeep i had my angles wrong, so it actually held the entire rear end of the jeep at full droop with the tires on the ground, welded it with flux core because i ran out of solid and it actually held, i have full trust in mig welders for anything youll put on a jeep, i wouldnt trust mig on something like construction equipment though
Well it all depends on the size of the welder. My mig don't get hot enough for anything other than tacking to hold in place or body work. Anything to thick and it will fall apart when weight is placed
 
#64 ·
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