Yulp, I've done the obligatory searching ... found 50/50 info on the Premier, little to none on the Mobi, and Jeff Fretwell's Home Brew Welder (http://www.pirate4x4.com/tech/on-boardwelder/index.html).

Jeff's idea is pretty slick, especially from a "build it, don't buy it" attitude. But, when it comes to things that spark, I would feel more comfortable buying a pre-engineered product. Additionally, mounting a Ford style alternator on my TJ's 4.0L could be tricky.

The Premier seems to be the standard, but at $800 it's also the most expensive ... granted you do get a new high output alternator.

Mobi's new Mobi-Arc looks to be rather slick and at $495 (special price until the end of the month) it's a heck of a deal even if it does not include the 110V outlet. The new Mobi-Power does include the outlet but is not yet available.

So, what's your opinions, Mobi, Premier, or ho-made?

Thanks in advance guys ... maybe some day my educated choice will save one of your tails out on the trail.

cmk

Call me a cheap bastard...but what is wrong with the tried and true "batteries and jumper cables" welding? Granted, a designated unit is pretty nice but like you said, the TJ's 4.0 doesn't leave a whole lot of room for one. I've got brackets sitting around for the XJ 4.0 to run a Ford ext reg, but I never got around to actually doing it. Don't know if the TJ would be all that different, but I will see if I can scrounge those up off the workbench and scan them if you want to take a look.

Get a 100 Amp Ford alternator from the Pick-n-pull do a Jeff Fretwell style welder. It doesn't have to be permanently mounted and you can even put it on the inside of the fender. You can control the amperage just by adjusting the speed. $15 and a couple of hours work and you can spark it up.

<img src="http://members.home.net/cglabe1/Air/Air24.jpg">

Pin Head
Where did you get the 110volt power supply from? The NAPA one seems a bit steep for me being unemployed and all.

Batteries and cables ... yeah, I would do it in a pinch. But looking at the guys I wheel with; some have Optimas, some have OE batteries, and some have less than that. I would fear stringing 2 or 3 unknown/different batteries together. Plus the idea of short circuiting a battery for welding purposes really scares me even though I know it's been successfully done.

Josh, if you have those brackets, I would greatly appreciate any specs on them that you have. Do your brackets replace the Jeep's OE alternator or just mount the Ford one in addition to the OE unit?

Pin, your explanation and picture do have me leaning towards the ho-made setup now, especially if I can easily mount a Ford alt. I presume that pic is from your own setup. Did you go with the Napa power supply or just run the cables right off an extra alt.?

Also, Premier's page talks about having to run one polarity when welding on someone else's rig and the opposite polarity when welding on your own. Am I correct in thinking that it's as simple as just swapping the connectors (red to red, black to black or red to black and vice versa)? I know it's a stupid question and probably has a stupid answer, like "yes."

cmk

Originally posted by EBSTEVE
Pin Head
Where did you get the 110volt power supply from? The NAPA one seems a bit steep for me being unemployed and all.


It isn't real clear from the article, but you don't need the NAPA regulator unless you want to run regulated 110V DC to power tools. I didn't think it was worth it.

The wiring is simple: Just run a wire from the field terminal on the Ford alternator (marked F) to the battery + pole when you want to weld. I use a short piece of wire with a spade lug at one end and an alligator clip on the other :smokin: I use jumper cables for a stinger and work piece: one from the + Bat terminal of the alternator and the other from ground.

You can easily run 110 V DC tools like an angle grinder with this set up as they put out 100-150 V depending on the engine speed.

I just made up a mount on top of my York compressor next to my stock alternator. I don't keep the Ford alternator mounted all the time. I have a total of about $20 in it and it doesn't get much easier or simpler.

The stringer beads shown in the top picture are made with the Ford alternator and 3/32 rod. The first and third bear are 6010 and the second and 4th are 7014 fast fill. No cooling down in between beads, so the duty cycle is good.

Yes, you can change either polarity just bw swapping leads, but you can only weld on your own rig in DCRP (DCEP) mode, since the ground on the alternator is always negative.

<img src="http://members.home.net/cglabe1/Air/Air26.jpg">

Very nice Pin head...cheap too

Nevermind the dumb questions. After some more searching, I found the answers I was looking for.

This ho-made setup looks more and more inviting. Now I'm starting to wonder if there are any advantages to the Premier or Mobi at all aside from the pre-packaged nature of their setups.

cmk

Doh! The other reason for the NAPA regulator is when you are using one alternator to do double duty in charging your battery and as a welder. If you are running a second alternator, it doesn't matter. You can even burn it up if you want. I haven't managed to burn it up yet, but I would rather use my buzz box at home. It wouldn't be bad even if it was the only welder you had; it's better than no welder. "If you can't weld it, you can't fix it"

Hey Pin Head, why don't you get with Lance and/or Jeff and see about updating/revising Jeff's writeup. You have some great info that would be a benefit to all. Plus, the next time someone asks, you can just refer them to the page rather than retyping everything.

cmk

Originally posted by Pin Head
Doh! The other reason for the NAPA regulator is when you are using one alternator to do double duty in charging your battery and as a welder. If you are running a second alternator, it doesn't matter.

As far as TJ's go, it appears that the Electronic Voltage Regulator (EVR) is built into the Powertrain Control Module (PCM). Because of that, I'm unsure if you could adapt a Ford alternator in place of the OE Jeep unit without getting into some reprogramming of the PCM to account for the higher output of the Ford unit.

With that in mind, I'm gonna' look at acquiring one of these high output Ford units and mounting it seperately off a second belt. That way, I can leave all my "high tech" Jeep stuff intact and have a dedicated welding alternator to fry, if I so "choose."

cmk

The brackets are nothing special. Basically the battery is moved to the passenger side and a bracket bolts to the AC unit's mounts. To power the alternator, a serpentine/v-belt combo pulley from Brad Kilby will work. Other than that, its just what Pin Head said. You can go hog wild if you want with a control box, quick connects, voltage and amperage meters, LEDs, lots of switches and crap. Or, just make it as simple as red to red, black to black, BUZZZZZZ.

I'll see if I can find those brackets. They are probably buried behind my workbench.

There is actually a post in the main board about fabbing up an onboard welder here:
http://www.pirate4x4.com/forum/showthread.php?s=&threadid=7238&highlight=weld

It includes part numbers, mounting pictures (on a Chevy 5.0L TBI), pictures of the welding stringer, and a wiring diagram as well as 2 pages full of comments, etc :p

Definately a fun and easy project.... cost me a total of about $150 for a "fancy" homemade onboard welder. I didn't opt to do the 110v outlet because I'll use the onboard air for tools :p

Originally posted by cmk
Hey Pin Head, why don't you get with Lance and/or Jeff and see about updating/revising Jeff's writeup.
cmk

Actually, there's nothing wrong with Jeff's write-up. You just have to read it. :rasta:

It is where I got the idea in the frist place.

Jeff's writeup is a good start, but if you decide to forgoe the Napa box, then you don't get the detailed instructions that you gave on how to wire up the alt.

cmk