Reactor in a portable Miller Big 40 welder?

Discussion in 'Electrical Forum discussion & Blog' started by inillinois2, Oct 27, 2009.

  1. jimbo

    jimbo Plumber

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    8,997
    Location:
    San Diego
    You can fix it yourself. No problem. Take a look at this African Welder.

    [​IMG]
  2. Rich B

    Rich B DIY Senior Member

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    283
    Location:
    New Jersey
    Very nice welding there JugDish. Where are your gloves and shield? Oh you don't need those, righhhhht! Mr Miller would be proud of your ingenuity....thats what he did back in the 20's or 30's

    I think you can get a coil wound right in the back of most any Dunkin Donuts or Quick Check....WalMart super centers also might have a dedicated group of coil winders in the back.........:rolleyes:


    It's all in good fun here gents.....
  3. Thatguy

    Thatguy Homeowner

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    I wonder how they make their Hi-Def TVs. . .:eek:
  4. Thatguy

    Thatguy Homeowner

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    MD
    I guess you could leave wire 37 disconnected, if the inconvenience of this 'costs' you less in dollars per week or dollars per usage of this welder, than the one-time cost in dollars to repair.

    Please post back how you decided this issue.:p
  5. inillinois2

    inillinois2 New Member

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    Location:
    illinois
    Am leavin the welder as is with one lead of coil unhooked. Usage is pry only about 20 hrs a year and have brand new Miller Bearcat 300 to use plus 3 other portable (propane) welders. Thank you all for your help on this matter, maybe look u up when the TMC 150 Thermatool) goes haywire, but can usually handle it! Thanx again !!!!
  6. Thatguy

    Thatguy Homeowner

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    1,459
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    MD
    Now if an OP comes along with a bad MIG welder, we can all reverse-engineer that thing. :p
  7. Rich B

    Rich B DIY Senior Member

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    283
    Location:
    New Jersey
    Mig welder = AC input power....main tranformer.....main rectifier.....cap bank.....stabilizer (Z-1 again)......control section......solid state for new style.....contactor, relay and pots for old stuff......wire feed motor drive and gas solinoid and a gun......No reverse engineering needed on those just bring it to me and I will fix it.......




    P.S. I have never heard of a Miller Bearcat? They make Bobcats, Trailblazers and have one machine called a Wildcat but no Bear cat that I am aware of anyway.......Whats in a name anyway? They are engine driven welder-generators and some are also Inverters........I have worked on most everything they make from big to small...Mig-Tig-Stick-Inverter.....


    P.S.2 for my friend ThatGuy the engineer........If you want a real challenge....try an Inverter based machine....good luck! LOL.... and be sure to be carefull there.......the cap bank on some of those machines has over 900volts of stored energy after the power is OFF! You could reverse engineer yourself right into the hospital with one false move......
    Last edited: Nov 12, 2009
  8. inillinois2

    inillinois2 New Member

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    Location:
    illinois
    Excuse me for the name mix-up, bobcat. Is brand new and right out of the box. haven't really even looked at it...........thanx for your input tho.
  9. Thatguy

    Thatguy Homeowner

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    I'm surprised I don't hear about people being killed while fixing microwave ovens. Supposedly, over 1 joule of stored energy can be fatal.
  10. Rich B

    Rich B DIY Senior Member

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    283
    Location:
    New Jersey
    I have never touched a Microwave and know zero about them. I have a Litton that is probably 25 years old and works fine. I don't use it much anyway. If it failed I'd throw it out in a heartbeat especially after reading some of this...



    http://www.repairfaq.org/sam/micfaq.htm#micsaf
  11. badnewsracer71

    badnewsracer71 New Member

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    6
    Location:
    new mexico
    1981 miller big 40

    I bought a big 40 minus alternator,I bought a used one on e-bay.there are 3 wires to hook up but i dont know where they go on alternator.please help
  12. Thatguy

    Thatguy Homeowner

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    MD
    Post a schematic/photo/spec. sheet/measurements.
    You can't tell the players without a program.:D
  13. Rich B

    Rich B DIY Senior Member

    Messages:
    283
    Location:
    New Jersey

    Are you referring to the battery charging alternator? I assume you are.

    You can use a GM style Delco alternator. 1 wire that is usually a little larger goes to the large post on the alternator. That wire should connect to B+. One wire would be the field excitation of the alternator and the third is probably a wire connection for a light on the control panel that tells you the charging circuit is working. Use a voltmeter. Probe the 3 wires. One is hot all the time. That is the one for the bigger post on the alternator. Start the engine and see which one of the other 2 is now B+ but was not before you started it. Your looking for a switched B+. That goes to your F terminal on the alternator. If you use a Delco internally regulated alternator you should have a post on the back for the B+ larger wire.....and a 2 pin connector on the edge of one side. One pin is F+ and your switched B+ goes there. Your third wire should go to the remaining terminal on that side 2 pin connector. You will have to try that one with a temporary jumper to be safe. Some of those machines might have an amp meter instead of a light and that could change the connections....


    I can look up most machines by serial number on the front of the machine.......2 letters and 6 numbers on one line stamped into the front panel. I can find prints and it also shows wire numbers...and all your wires have numbers on them if you look closely.....
    Last edited: Dec 6, 2009
  14. badnewsracer71

    badnewsracer71 New Member

    Messages:
    6
    Location:
    new mexico
    miller big 40

    thanks so much.that is so helpful.was afraid of hooking up wrong and burning something up
  15. badnewsracer71

    badnewsracer71 New Member

    Messages:
    6
    Location:
    new mexico
    miller big 40

    I put alternator on as instructed.new battery.I checked fuse on emergency kill,the button you hold in while starting.I flip switch to on.Push starter button while holding other button in.I have nothing.I have checked all connections.This machine sat for over 4 years.Any ideas on what to check next?
  16. Thatguy

    Thatguy Homeowner

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    1,459
    Location:
    MD
    See post #32.
  17. badnewsracer71

    badnewsracer71 New Member

    Messages:
    6
    Location:
    new mexico
    miller big 40

    I just found this site yesterday.Dont know how to see post #32
  18. badnewsracer71

    badnewsracer71 New Member

    Messages:
    6
    Location:
    new mexico
    the serial # is jb 503942.
  19. Rich B

    Rich B DIY Senior Member

    Messages:
    283
    Location:
    New Jersey

    You need to explain a little better what "you have nothing means". Does this mean it doesn't crank, doesn't start, doesn't charge? If it has a starter pushbutton and another button that says hold in while cranking.....that is a Murphy switch...it overrides the low oil pressure switch so the machine will crank and start. Fuse on emergency kill ???What are you referring to there??? If you have a good battery......use a jumper to see if the starter cranks....B+ to the Solenoids S terminal. If it cranks.....does it have a distributer or a mag? If it has a distributer jump B+ to the coil + side and crank it. See if you have spark. If it has a mag it will make spark unless the mag is bad or the small wires going to the mag is grounded. An old machine that has been sitting for 4 years will likely need work and I do exactly as I described to see if it will run. I would tackle the control issue AFTER I determined it was a machine that could be a usable piece of equipment. It makes no sense to buy and install parts if the machine has something major wrong with either the engine or the main electrical generating end......
    Last edited: Dec 7, 2009
  20. badnewsracer71

    badnewsracer71 New Member

    Messages:
    6
    Location:
    new mexico
    miller big 40

    I bought it for 200.00 for parts.I figured it was worth a shot to get it running.After i posted last message i found a broke wire.repaired wire,started machine,and welded with machine.I need to rebuild carb,other than that it welds great
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