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problems with my 251??

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  • problems with my 251??

    i have a new millermatic 251 and for the most part it has worked flawlessly. I was welding on some .134 mild steel tubing the other night and as i was welding, at times it seemed like it would lose it's arc and then start arcing again.. while the are was out i could still hear the gas coming from the nozzle.

    my settings were 17.0 volts & 245 wire speed (1/8th inch tubing) also using 75/25 argon/co2 gas. Tank has plenty of gas and is regulator is set to 25.

    power is being supplied through a 50amp breaker. I verified that the wire is feeding ok and gas doesn't seem to be a problem.

    out of ideas... help?

  • #2
    a simple little trick.

    Remove the nozzle, with the contact tip {where the wire comes out} still on the gun, put the contact tip in a vice and tweek {bend ever so slightly} the contact tip. This will insure that the wire {due to the cast and twist of the wire} is always in constant contact with the contact tip so you don't loose the arc. Other than that, check the ground lead.
    Mike. R

    Dynasty 300dx tig runner w/ 3 torch Versa-Tig torch changer {wt-20f, wt-24f, mt-125}
    MM 251/30a/4015 roughneck
    Miller portable spot welder
    Inferno >>> Big Window Elite


    • #3
      Let us now what the problem was. I have a mm251 also. I guess you are using a new roll of .035 wire...? Double check the drive rolls to make sure they both are turned for .035 and make sure you have a .035 tip. I use about 2.5 on the wire tension knob for a 45lb roll. You might bump the volts up to 17.5 and see what the meter reads after the arc goes out. I always double check these things because I'll surely mess something up if I don't.


      • #4
        Agree with previous post, check the drive rollers & make sure you have them tensioned correctly. The wire to floor test to insure the feed is constant.
        Keep us in the loop on your status.


        • #5
          Its fixed !!!

          tightened up the tension rolls to 2.5 and it is welding awesome now. Thanks for the tips. Glad this board is here


          • #6
            Glad to hear you got it running right.