Miller welder wirefeed problem...

[JMortensen]

After touting the MM135 for a year since I bought it I'm having my first problem with it, and hoping somebody here can help.

 

What's going on is the wire will break in the box repeatedly. It looks as though the wire is BURNED in the box too, not like it is breaking because of too much tension. This happens right at the beginning of the liner leading to the gun.

 

I played around with the spool tension and was hoping that I had fixed the problem, but this keeps happening, and I think there might be something else going on. The wire comes off the spool, through a little funnel, between the two rollers, then just as it goes into the liner that's where it keeps burning through.

 

I played with it some on the bench and it was welding PERFECTLY. When I got into the kind of funky position that I need to be in to weld my patch into the firewall, my welding angle wasn't as perfect. Instead of crackling for a second and then settling into a steady buzz, as soon as the arc starts and hesitates you can feel the wire suddenly stop feeding and it looses the arc. It will literally only weld for about 1/10 of a second. There is a little round ball on the end of the wire which sometimes is right on the tip, but usually about 1/4" away from the end of the tip. Pull on that little ball and all of the wire comes out of the cable, open up the case and you can see the burnt end at the end of the liner. Feed the wire through, everything is fine again, get down into position, try to start the arc, wire breaks again.

 

Same thing over and over. Any ideas? F'ed up liner? Can I pull the liner out and possibly find the kink? Why does it look burnt where it breaks though???

[JMortensen]

Nevermind, I seem to have fixed it.

 

All I did was start to pull the cable out, then put back in. When I plugged it back into the box I rotated it a bit. There was a sharp edge on the cable, and I didn't take it off, but I did rotate it, and it seems to have made all the difference. Back to 100% bitchin welding...

[Mikelly]

You might want to replace the liner. I replace mine every other year just to make sure there are no feed issues.

 

MIke

[mom'sZ]

that's what I was going to say Jon, sounds like the liner. You may have stepped on, run it over, dropped something on it or whatever. I had one and you could twist it this way or that and it would weld, then you would crawl up in the car and get ready to weld and.... errrrrrr

[tube80z]

Another useful item to add is the little felt lubricator/cleaner before the liner on the inside of the machine. It will help to make things work/last a little longer.

 

I've also found is that some liners are made much better than others. When I adjust tension I set it so that the drive wheels just slip if the wire is pushed directly into the concrete floor. That's saved me from dealing with bird nesting.

 

I don't know how I could function without a welder.

 

Cary

[JMortensen]

This is my theory: when they cut the liner, they left a jagged corner at the end. This jagged edge was positioned at 12:00 the way I originally installed the liner. I think that I might have had the tension too high so that the wheels don't slip. So instead of a little slippage, if something happened at the other end the wheels would continue to drive the wire. The wire would bend in the direction of the jagged edge, which was the problem.

 

This might be really retarded, but one thing I don't understand about mig welders is how you can put current through the wire without the whole spool just welding itself together. Is it possible that the jagged edge snagging and scratching the wire was what was causing it to burn up there instead of at the end?

 

Regardless, it is working 100% of the time now. If I have a problem again I'll definitely replace the liner. Right now I'm off to buy more gas. As soon as it started working again the stupid thing ran out of shielding gas...

[JMortensen]

OK, a friend just explained it to me. The arc goes from the tip at the gun to the ground cable, and there is no ground on the spool. So when the wire snagged it must have been hitting a ground somewhere inside the box. Or maybe the liner was just grounded enough to melt the wire where it snagged.