The advice I've seen for setting MIG welder adjustments talks about the characteristic frying-bacon crackle. On a test piece I was welding last night I couldn't get it to buzz. The arc was making a kind of hissing noise, and the weld bead was being laid down in blobs rather than a continuous bead. Can anybody tell me which direction to go with the settings?
3/16" steel, .030 wire with 75/25 gas.
Thanks.
What current/wire speed and voltage were you running? How much stick out were you running? Gas flow rates? etc....
John Wright
Gas flow is 2 ltr/min. Voltage and wire feed settings on my machine are not calibrated, just relative. Voltage was set at 3/4 (I have 4 steps) and wire feed about 2/3. I suppose I could measure it in ft/min but it's not calibrated. Stick-out was about 1/2", just enough to see the arc from behind the nozzle.
Dave, sounds like you have you voltage way too high for your wire speed.
Mike Sherman
Dave,
That is where I was heading with all those questions.
Let us know if it helps,
John Wright
sounds like you need to increase your wire speed or decrease your voltage. try setting the voltage and keep one hand on the wire speed dial and adjust it while welding
I increased wire speed and it got better, but then started popping. Decreased voltage seemed to make it worse, the wire started burning off near the nozzle instead of feeding into the weld.
I thought MIG was supposed to be simple...
Dave, at this point stop. Reset all parameters to manufacturers recommendations. Once you have done this, tell us what those settings are.
Mike Sherman
Mike,
Dave mentioned he was running his gas flow at 2 liters/min. Where or how does that relate to cubic feet/hour. All our machines have cfh guages on them.
John Wright
LPM are roughly half what CFH are. 2 would be very low, to the point where I don't think he would have hardly any shielding. I would think he needs to be at about 12 lpm.
Mike
1 cubic foot = 28.3 liters. 60 minutes in 1 hour. Therefore, 1 liter per minute = (1/28.3)*60 = 2 CFH, just as Mike Sherman said, so 2 lpm = 4 cfh. Very low. Even with small cup GTAW, flow rates run 10-15 CFH minimum.
We are using 100% CO2 and need about 40 - 50 cfh to cover.
John Wright
We use 75/25 and can often use half that.
Mike
The ONLY setup spec I got with this machine is to use 2 lpm/4cfh for the gas. They say to increase to 3-4 lpm for windy areas. I was welding in my workshop.
Polarity is wire positive, not changeable.
What affect does too low gas flow cause?
Is polarity correct? Just a thought.
Dave P.
I remember several threads started by bzzzzzzzzzz along these lines. Read those they may help. It seemed in the end that the machine in question was faulty.
Sometimes popping like that can mean either that you are too far away or you are too far back in the puddle.
Perhaps you could have somebody check the voltage (from weld cable to ground cable) as you weld.
Bad ground causes all sorts of wierd results.
All I can think of for now.
Bill
yes, I believe that machine was just too touchy with the wire feed. the Challenger 172 I bought is much easier to keep the arc going. I believe the 75 amp simply needed a much smoother wire feed mechanism for the low amps it had. The challenger may not be quite as nice on thin stuff,but it sure does the job on thicker stuff as long as it's clean and prepped properly. Learned a little from that 75 amp critter though. Also appreciated all the responses to my posts on the 75 wire feed. One thing I did notice on the Miller... The gas nozzle is shorter, (or the contact tip is longer),thus allowing you to have shorter stick-out. Could have caused some of my problems with the 75 amp. My old welder only allowed you to shorten stick-out so much as the nozzle end would interfere at a certain point. That's ancient history for me now. Overall the Miller 172 seems like a solid mig unit.
Hi bzzzzzzzzzz- good to see you are still around. You once said you were making sugaring pans. I assume thats going well and you will be sending us all those free samples soon. Just kidding about the samples.
Be well
Bill
Hi Dave
Usually a hissing sound is an indicator of spray transfer, while the "frying bacon" sound is an indicator of dip transfer. (Not VERY scientific, but is a reasonable rule of thumb.) With the 25% CO2 in your gas, you will struggle to get spray transfer. Rather, it will tend to globular transfer at higher voltages.
I suggest that you lower your voltage setting significantly and try again. As stated in some of the other posts, I would increase the gas flow as well. (Are you sure of the units on your gauge?)
Regards
Niekie Jooste
I have the same lph or watever on my firepower mig welder gauge. I run 5-10 lph. I think the last time I used my welder it was at 7-8 lph. I have a 120 firepower welder.
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