Hobart/Miller experts Mike or Kevin

[Dan]

My new MM 175 that I recently purchased consistently has poor (popping) arc starts on 1/8" and 3/16" Mill scale free mild steel with an .030 or .035 solid wire and C-25 shielding gas. Im curious is there an adjustment that I can make internally on the machine to eliminate this proplem. So you know, I always trim the ball off the wire before every start, and I trim the wire back to a 1/4" or less , and then hold a 1/4" to 3/8" stickout. Also, there are no loops in my input power cord. This popping arc start occurs with the door chart settings or at my own settings.

[Hobart Expert Rock]

HI DAN...............YOUR OUT OF LUCK...........MIKE IS FISHING IN CANADA AND KEVIN IS DOING A SHOW.............. DOUG OR MARIE ARE THE ONLY ONES THERE.............. AND I'LL BET THEY ARE VERY BUSY........... TRY THIS FOR ME HOOK A VOLT METER UP TO THE OUTPUT STUDS AND STRIKE AN ARC........... SEE WHAT THE WELD VOLTS REALLY ARE............. ALSO IS THE START CAUSEING POROSITY................................ROCK...... ........
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[Dan]

ROCK
Darn it! Something like this always seem to happen on the few occasions that I have actually had a question. Oh well, for now if I actually need the smalller machine I have my HH 175, which by the way has excellent arc starts.

Luckily, I had my wife measuring the load voltage for me on the 3/16" material that I was welding. The load voltage with the settings on the door chart was on average 20.2 volts. The load voltage with my settings was on average 18.6 volts.

There is no visible porosity at all. So, I would assume that it is not a shielding gas problem.

I have even tried a "NEW" contact tip too. Same results. The arc with my settings is a nice crisp stable arc once the arc gets past the poppy start. So, I feel that I have the drive roll and the wire roll hub tension set properly.

I ve basically tried everything I know. So, I m assuming a trim pot might need a little adjusting on a board. Just a guess though .

[Hobart Expert Kevin]

Dan,
I would double check your drive roll tension, spool hub tension, etc... stumbling most of the time comes back to either a feed issue or just to much wire. Low power input could also have a big effect on the start performance. I will try to set a unit up tommorrow and run your setting to see what results I get here.
I was supposed to be gone this week but my plans changed a little so I will be here until Thursday for sure. I will let you know what I get for results ASAP.

Kevin



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[Dan]

Originally posted by Hobart Expert Kevin
Dan,
I would double check your drive roll tension, spool hub tension, etc... stumbling most of the time comes back to either a feed issue or just to much wire. Low power input could also have a big effect on the start performance. I will try to set a unit up tommorrow and run your setting to see what results I get here.
I was supposed to be gone this week but my plans changed a little so I will be here until Thursday for sure. I will let you know what I get for results ASAP.

Kevin



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Kevin

The input voltage to the machine varies between 238 to 240 volts depending on the time of day. The welder is being supplied power from a 50 amp circuit with a properly sized conductor.


I plan on playing with all the variable some more this week. I have 5 different wirefeed machines and this is the only machine that has poor arc starting problems. In 15 years I ve never had a problem setting a machine up to produce quality results, however this one is a challenge. The funny thing is the machine that I set up at the welding store didn t have this poor arc starting problem So, because of this, I wanted to know if there was any internal adjustment that I might try.