Miller MP 30e Puzzling Behavior

[alphonso]

Miller MP 30e with 30-e wire feeder. Tweco gun. Running steel wire, no problem. Run stainless wire and frequently welds to tip and wads up wire at wheels. Getting worse. Played with voltage and feed rates. Doesn't seem to make any difference.

Replaced liner, wire guides, feed wheels/gears. Some days will weld for hours without incident. Other days, yesterday!!!, welded to tip 6 times in 30 minutes.

Any insight???

 

[Pattnmaker]

Is it while Welding hot? I found using the heavy-duty tips made a huge difference for me. They're a little heavier wall.

 

[Mud]

I've had a couple MIG welders where I had to jack up the spring pressure on the feed wheels way beyond what the manufacturer allowed for to get it to feed right. This is after trying all the things you tried. Don't know if this is relevant to your machine, but was the first thing I thought of when reading your problem.

 

[Herding Cats]

Maybe try a Teflon liner

 

[alphonso]

Is it while Welding hot? I found using the heavy-duty tips made a huge difference for me. They're a little heavier wall.

Not sure what you mean by "welding hot". Voltages we played with are 40 to 50%. Volt and amp meters are suspect in that they cannot be zeroed. Shows about 18+/- volts at 50%. Wire feed 40 to 60%. Best sounding is at 50%.

Sometimes will tip weld on the first trigger pull of the day, sometimes after an hour or more of runtime.

Wonder if maybe brushes in feed motor need attention. Only been using this machine since 1988, bought used.

 

[Pattnmaker]

I meant using the welder turned up high. I probably should have bought a bigger welder when I bought mine and I tend to have it at the second from the highest or highest setting most of the time. The welding shop recommended the heavier tips when I was having some tip welding issues. They only cost an extra buck or 2 and I have not had a problem since as long as my liner is in good shape.

 

[Gordon Heaton]

What are you running for shield gas with the stainless?

 

[alphonso]

98 -2 or 95-5. Doesn't seem make any difference.