Welding Tips and Tricks

So I finally took my Millermatic 211's cover off so I could clean it after two years. Definitely needed a dusting.



I was surprised to see the size of the small fan that is responsible for the cooling of the unit! Maybe if Miller had put in at least a 4" fan it would have a better duty cycle. Oh well, it doesn't bother me as I have never had the need to set it to kill for more than a minute or so.



so this is the sucker that is wobbling on me. Ended up finding a replacement for $60. Gonna swap it out when it gets here.

No kidding?

How much time do you have on it? I got the impression working in a welder repair shop that Millers were notoriously sturdy and well built.

Would you say that may not be the case with this model?

Hard to say because the one we bought at my work doesn't have "the wobble" and feeds better than mine. The one that ChuckE2009 showcased in one of his videos behaves exactly like mine. You can see the tension knob bob up-and-down just ever so slightly as it feeds the wire. It works just fine if you crank down on the tension, but if it ran 100% true (or very very close to it), it would work even better with less tension, leaving more available for situations like when adding a 15' mig gun.

I have ran maybe 50-60lbs of wire through it, strictly hobbyist here. I'm sure there are different acceptable levels of "sturdiness" that can be defined.

Brand new drive motor assembly installed. Two different drive wheels. I guess that's just how they are. Oh well, I mean it still works, just have to tighten down to about 3.5ish.

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Here is the unit we have at my work. With the naked eye, I think I can see a teensy weensy bit of wobble if I had to guess, maybe 0.010-0.012" of run-out off the surface of the drive roll. Not like mine which has a visible, oh 0.020-0.024". (just guesstimates).

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All in all, I'm not too disappointed because the unit does work when the necessary amount of tension is applied to the rollers. I just know in the back of my mind that it could be done with much less tension if everything was true.

Oscar
did you ever contact miller about the "wobble?"
m having problems with my 140 and considering buying
the 211 but i don't want to start out with a problem
and might look at others.
craig

I did, but I cant find the email. Even then, it probably said to take it to a service center, which I did and it was deemed perfectly ok to need to use more tension, and didnt actually do any servicing on the unit.

I'll probably end up keeping it, but I still want either an HTP ProPulse 200 or 300.

Oscar
thanks
craig

Made some headway with my drive assembly issue:

Measuring the concentricity of the original drive motor shaft using my lathe chuck.

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Looks like 0.013" +/- 0.003" to account for lathe chuck TIR. I think I found the problem, lol. Would be a good first project for my Smithy 1220 LTD. That and for the replacement motor I ordered, but that one is installed in the machine. I also want to make a nozzle for my HTP M25 MIG gun for when I use flux-core wire, as such a nozzle for that gun is not available.

Here it is with the drive roll installed. About 0.010" on the roll, right between the 0.030/0.035" groove and the 0.023" grove. So yup, as it droops down on the low-part, some tension is lost because the spring relaxes, hence some slipping if you don't give it 3+ on the tension knob. So my original hypothesis was correct, the drive shaft is indeed wobbling causing the drive roll to wobble, affecting the net pressure on the mig wire.
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Almost there! Neat 1st machining project, new motor shaft for drive assembly. Dinner calls, so I'm gonna pick this up later this week.
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