OBW with 2nd alternator fab

So I used a OBW on Ray P rig in moab a couple of years ago and since I finallly saw how two batteries and jumpercables weld :speepin:
I decided to have a go at it
here are some pics
looks like Im going to have to get another Sbelt for this to work on the trail..
should work somethin like this
lossen PS pump take of S belt
put on 2nd alt
put on other S belt
tighten it up
and weld

permanant mounting plate and jig ready to go on


still in the adjustment phase ..just gotta find some parts store guy who wont mind sifting trough all the belts to find a appropiate lenght

I've thought of doing this for an on-board welder also. I like your setup. However it looks as though that the alt would stick up to far to get the hood shut.

Looks to me like he throws it on when needed.

A suggestion- Why not weld on a v-belt pulley? That way when you put your 2nd alternator on, you don't have to screw around with swapping sbelts.

so then your first alt charges your battery that runs the vehicle - does the other alt charge the other battery? or are they both used to charge your main battery?


also what leads are you going to have coming off this alt?

One Ton is correct the top plate is mounted permanant the second plate holds the alt and when needed I install it and use it

I thought about the V belt pulley hookup..clearance might be and issue pertainng to the drive pully.. Im really leaning towards that though.. My first measurements had me thinking that the OEM belt was long enough..Still in the R&D stage

here is the link to Rays pics btw the thing works really well

http://www.kodakgallery.com/ShareLa...e=fromshare&Ux=0&UV=345708474802_933969987203

Ranger
the second alt doesnt do anything except generate a AC field
actually it will run a brushtype motor 110 device(like a 4.5" grinder or a blender )

VegasAnthony said:

One Ton is correct the top plate is mounted permanant the second plate holds the alt and when needed I install it and use it

I thought about the V belt pulley hookup..clearance might be and issue pertainng to the drive pully.. Im really leaning towards that though.. My first measurements had me thinking that the OEM belt was long enough..Still in the R&D stage

here is the link to Rays pics btw the thing works really well

http://www.kodakgallery.com/ShareLandingSignin.jsp?Uc=19houtsz.6kk5khz&Uy=3hvmkt&Upost_signin=Slideshow.jsp%3Fmode%3Dfromshare&Ux=0&UV=345708474802_933969987203

Ranger
the second alt doesnt do anything except generate a AC field
actually it will run a brushtype motor 110 device(like a 4.5" grinder or a blender )

Click to expand...

so the second alt is the welder - not another battery?

i havent looked into homebrew welders much - enlighten me...

-Opie

XJ_ranger said:

so the second alt is the welder - not another battery?

i havent looked into homebrew welders much - enlighten me...

-Opie

Click to expand...

this writeup is awesome
I kinda using option 2

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

Interesting. What alternator are you running. Is it an external regulator type?

It would be good to figure out how to use an alternator identical to the one in your Cherokee, so you would have a spare.
I need to take a Chrysler alternator apart to see if the internal regulator can be easily bypassed.
Keep up the good work.

lazyxj said:

Interesting. What alternator are you running. Is it an external regulator type?

It would be good to figure out how to use an alternator identical to the one in your Cherokee, so you would have a spare.
I need to take a Chrysler alternator apart to see if the internal regulator can be easily bypassed.
Keep up the good work.

Click to expand...

I emailed Ray P abou this subject he said

" I used a Dodge/Jeep alternator. I have a 90 amp alt and it seems to work just fine. The jeep alternator is externally rectified by the computer. So you dont have to worry about removing anything. All you need to do is hook up +12 and ground to the two small bolts in the back of the alternator like on pic 11 of the ofoto link I sent you. I wrote some comments to explain.

The two small bolts is where the regulator controls the out put of the alternator voltage. If you ground one and put +12V on the other the windings get a full 12 volts to generate the strongeest magnetic field (like an electric magnet). So the output is completely controlled by how fast you spin the alternator.

You can test this on the garage floor. Hook up an multi meter to the alt output (the big bolt with the plastic shield) and the alt case or ground bolt. Then hook up one of the small bolts to a battery + and the other small bolt to - of the battery. Then spin the alternator with a flick of your wrist. The meter should jump up a few volts. I dont remember if the battery to the small bolt matters but as long as you get + out of the alternator output thats what you want. I think it does not matter but I can conform it.

For my engine I loosened up the belt using the tensioner then looped the belt off the idler pully, then pulled it over the second alt. The tensioner when released put the right tension on the belt.

I dont remember how the 4.0 tenesions the belt. Cant help much there. I did not see an attachment so resend it.

As far as the power of the welder. This one is a 90 amp alt. I hear there are 110 amp alts also, but I could not find one. Maybe one off a grand cherokee with power everything has one. But you used it and it burns 3/16 rod easily at around 1600-1700 rpm. I've used it to burn a 2.5 inch hole in 3/16 steel. Plus fix a spindle and a flat tow plate to a bumper and a few other jobs bot at home and on the trail. And this alt has not failed yet. "

just as another side note on this
there is a fixed alternator setup possible
these threads are excellent

by wanderwillys on Pirate

Search would yield:

http://www.pirate4x4.com/forum/showthread.php?s=&threadid=115595
http://www.pirate4x4.com/forum/showthread.php?s=&threadid=111835&perpage=25&pagenumber=2


My setup is presented in the upper thread and also mentioned a little in the lower one...

Misc pics here:

http://home.off-road.com/~wanderingwillys/xjpics/Underhood/OBW/
Enjoy...

Matt

ahhhhhhhh Ok so I found a longer belt that rotes over the second alternator..





a test run and it spins nice!!
so it weld..

Now the longer belt has to be swaped in with the second alternator..(doesnt take but 10min to swap in everything..)

But I figure if put some spacers in under the AC compressor the new belt will be short enough to run the stock routing yet long enough to route oever the 2nd alternator..

just in case anyone is intrested in doin this
I have the part # and specs for everything I did :lecture:

VegasAnthony said:

I have the part # and specs for everything I did :lecture:

Click to expand...

well?

list them up

and lets see your control box.

cool project

im not gonna use a control box (lack of funds right now) but it I was I would use somethin like this

http://home.off-road.com/~wanderingwillys/xjpics/Underhood/OBW/control_box1.JPG


I found a used 90 amp alt on ebay for $32 shipped
(could have went to the pick a part)

the belt is
GM #12555009 serpentine poly-V belt. This is new genuine GM OEM stock with the following specifications:

Metric part number: 6PK2570 (6PK2565 at Autozone)
Goodyear part number: 4061010
Length: 101.0"
Number of ribs: 6

some 1" sqare tube

a 5" c clamp for the tension adjuster

some 1/8" plate
misc nut and bolts for mounting

Im using battery cables for the welding cables. wire till I get my hands on some good welding cables

a vice grip for a stinger

and a cable actuator from a ten speed for a hand throttle to vary the engine rpms

they nice thing is you can do this bare bones or hi tech which ever you prefer

If I didnt already have a bigg 225 buzz box I would prolly go hi tech so I could use this
as a all the time welder

wiring is as follows
cept for Im using a 90 amp alt
and the voltmeter is an extra goodie if so desired

http://www.trailhed.com/welding/altdia_small1.jpg

image from jeeplvr on Pirate

Anthony,

Have you tried your welder yet?

Ray

rpili2001 said:

Anthony,

Have you tried your welder yet?

Ray

Click to expand...

no not yet
but I cranked it over and got some good reading on the voltmeter..
just been busy its time to go wheelin tight now the temp is coming down quite a bit in the desert