No announcement yet.

slow wire feed?

  • Filter
  • Time
  • Show
Clear All
new posts

  • slow wire feed?

    I bought a used Miller 172 a while back. It's a great machine and I can't imagine turning loose of it but until recently, I could set the speed at 30 sometimes less for thin metal and weld great. Now if it gets much under 40, it pops and cracks and the weld isn't as good as it could be. I've loosened the tension at the drive roller and the wire spool and no improvement. Is there anything else to do or this the way it's supposed to be? Thanks!!

  • #2
    Are you sure the drive rolls aren't slipping on the wire?


    • #3
      I'll check that thanks!


      • #4
        New tip ,blow out liner.


        • #5
          It was the tip.


          • #6
            If the machine was pre-owned, and/or has had plenty of use, you should think about replacing the liner ASAP. A new liner will most likely make the wire feed smoother and ensure a more consistent speed, assuming everything else is in order. Also, disconnect the output terminal and check the wire feed rate at each multiple of 10 or so, such as 20, 30, 40...through max ipm, and verify that your measured feed rate matches with what the machine indicates. Time the feed for 10 seconds, measure the length of wire that has come out of the gun tip in that 10 seconds, and multiply that length by 6.
            Use the least amount of roller tension that allows the highest feed rate. This can be an unbelievably low tension, and that corresponds to longer roller life and longer liner life due to less copper cladding fouling getting peeled off the wire due to too high roller pressure. Once happy with roller tension, be sure to copy in your notebook all your measurements in comparison to the machine's readings, roller tension setting and wire size/type, for future reference. The machine probably will not give an accurate feed reading no matter what you do to correct it, so always refer back to your notes on critical welds (they always are critical!)

            Some experimentation and measuring will go a long way to ensure your machine has long and happy career.

            Now reattach that output terminal so you can weld once again.

            Ed Craig, a leading Weld Engineer, when consulting on problems with robotic MIG welders, always suggests replacing the lead liners at least once per week or sooner in a production environment. Yeah, it's that important for reliable operation. Nine times out of ten, the elusive, erratic, feeding problems lay somewhere within that liner.