MTS 211Si chirping at high amps in MIG mode

[ColoScott]

I've been welding mostly MIG with this machine for about 2 months no, mostly hobbiest type projects, and have had no issues. This past weekend I started fabricating a snow plow mount using some very heavy mild structural steel. Most of the components are 3/8 thick, some 5/16, and a couple are 1" thick. I put a roll of .045 in for the first time and started with the amps at 180. I was in Syn mode Mig (Syn mode is all I've used since getting this machine) and right away the welder started making a chirping sound at slightly less than one chirp per second and the welding action was stop / start / stop / start over and over. The weld not surprisingly did NOT look good. I checked ground to no avail. I re-positioned the ground twice, it didn't help. I was able to get a continuous weld without the weld doing the chirping sound but to do so I had to turn the amps down to 130 and even then it would do the chirping and stop start if I put the torch down in a normal distance from the weld. I ended up going back to .035 to put the tack welds in but I do want to be at the .045 and higher amps to do the final welds.

Does anyone have any ideas or have any of you seen this?

Thanks!

Scott

[zoama]

Do you have the work clamp on clean steel with no rust or mill scale?
Do you feel the wire stubbing into the weld?
Did you adjust the drive roller tension so that they don't slip?

[ColoScott]

I moved the ground around to 3 different locations but I didn't grind any off the locations for the ground clamp. I can try that this weekend.
Yes! The wire was stubbing into the weld, that's exactly what was going on and it was in unison with the chirping sounds.
I adjusted the wire feed tension when I first loaded it and also had someone look at it while I welded. They didn't see any sliping...i.e. the spool never stopped.

[zoama]

Sounds like poor contact with the work clamp. Try grinding a spot clean for it and let us know how it goes.