[DavidR8]

Hi all, I have an old Millermatic 130 110v MIG welder setup with .030 and 75/25 running on a 20A 110v circuit.

I wrote to Miller for the voltage specs for the four position voltage selector.
From lowest to highest they are:
20.5
22.8
25.7
28.3
I have no idea how these voltages compare to other machines but when I set the machine to the settings in the cover, they seem very hot.
For example, I was welding 1/16" wall sq tube and the suggested settings were voltage 3 (25.7 v) and WFS 50 (300 IPM)
There was no way I could avoid blowing through at those settings. I eventually settled on voltage setting 1 (20.5v) and 150 IPM. No blowing through and good penetration.

Tonight I was working on my welding table and I was joining 1/6" cross members to 1/8 table legs.
Suggested setting were voltage setting 4 (28.3v) and 300 IPM. I did some test welds and there was no way I could move fast enough to not burn through.
I settled on setting 3 (25.7v) and 220 IPM. I focused the heat on the thicker table legs and it worked very well.

I have no experience with no other MIG machines. For the folks with machines that have voltage readouts, I'm curious if my setting are in the range of what you might use in similar situations.

[Oscar]

Those voltages are very high for 030 wire on a 130A MIG. Typically short circuit voltages for 030 wire range from about 16V up to about 22-23V or so. Higher than that it starts to transition into globular and it makes a BB mess everywhere on some machines.

[tweake]

i suspect thats open circuit voltages not run voltages.
the voltage will drop when welding depending on wire speed (more amps you draw the lower the voltage will be).

i suggest adjusting the old school way, weld a bit and adjust to suit.

[DavidR8]

i suspect thats open circuit voltages not run voltages.
the voltage will drop when welding depending on wire speed (more amps you draw the lower the voltage will be).

i suggest adjusting the old school way, weld a bit and adjust to suit.

Thanks tweake,
So when a machine is set to say, 18 volts on the display, the actual voltage will drop while welding?


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[tweake]

i suspect thats open circuit voltages not run voltages.
the voltage will drop when welding depending on wire speed (more amps you draw the lower the voltage will be).

i suggest adjusting the old school way, weld a bit and adjust to suit.

Thanks tweake,
So when a machine is set to say, 18 volts on the display, the actual voltage will drop while welding?


Sent from my iPhone using Tapatalk

depends on the machine.
yours doesn't have a display and afaik its a transformer machine.
with modern inverters, you set the voltage and it adjusts itself to produce that voltage regardless of what current is being output.
older simple tapped transformer machines won't do that. the voltage will drop when under load which is why they have mentioned such ridiculously high voltage for such a low powered machine.

if you have the time and gear, set up a volt meter and amp meter, and record what voltage and amps you get at various settings. make your own door chart.

[Oscar]

i suspect thats open circuit voltages not run voltages.
the voltage will drop when welding depending on wire speed (more amps you draw the lower the voltage will be).

i suggest adjusting the old school way, weld a bit and adjust to suit.

Thanks tweake,
So when a machine is set to say, 18 volts on the display, the actual voltage will drop while welding?


Sent from my iPhone using Tapatalk

depends on the machine.
yours doesn't have a display and afaik its a transformer machine.
with modern inverters, you set the voltage and it adjusts itself to produce that voltage regardless of what current is being output.
older simple tapped transformer machines won't do that. the voltage will drop when under load which is why they have mentioned such ridiculously high voltage for such a low powered machine.

if you have the time and gear, set up a volt meter and amp meter, and record what voltage and amps you get at various settings. make your own door chart.

Yup, exactly this.

[BugHunter]

Open the door on your machine and also check to see that you don't have a lug you can move to go from high range to low range. Sounds to me like they gave you settings for low range but your machine is set for high. Mine is just a copper bar which you attach to either one set of studs or the other.

[DavidR8]

Open the door on your machine and also check to see that you don't have a lug you can move to go from high range to low range. Sounds to me like they gave you settings for low range but your machine is set for high. Mine is just a copper bar which you attach to either one set of studs or the other.

This is the interior of my machine. The lugs to switch polarity are in the upper right corner.
Other than that I don’t see any thing that can be changed.



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[BugHunter]

Well I guess you don't have one then. It was worth checking.

That was the only thing I can think of that would make it so hot.

[BugHunter]

I have a Hobart beta Mig which has that dual range Transformer. Running a 35 wire my voltage tap which goes from 1 to 10 is down at 1 or 2 and the wire feed is up at 7 to 10 which equates to 450 to 700 inch per minute. It really should be on low range for me to run 035 wire.

[cj737]

Better to run 0.024 wire with those thicknesses anyway.

[DavidR8]

Better to run 0.024 wire with those thicknesses anyway.

.024 for 16 ga?


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[cj737]

Better to run 0.024 wire with those thicknesses anyway.

.024 for 16 ga?


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Sure. I run it all the time, even up to 3/16” for frames and whatnot around the shop. Set it hot, and burn it in. The wire speed will fill the weldment. I think it will be much easier for your box on 120v to give you better performance with that wire diameter anyway.

[DavidR8]

Better to run 0.024 wire with those thicknesses anyway.

.024 for 16 ga?


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Sure. I run it all the time, even up to 3/16” for frames and whatnot around the shop. Set it hot, and burn it in. The wire speed will fill the weldment. I think it will be much easier for your box on 120v to give you better performance with that wire diameter anyway.

I will definitely try it out. Coincidentally my welder came with a large size spool of .024 wire that’s just been sitting there.


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[cj737]

I will definitely try it out. Coincidentally my welder came with a large size spool of .024 wire that’s just been sitting there.

Probably a clear hint that you missed

[DavidR8]

Using my Fluke 77 meter I checked the voltages under welding conditions for the four different levels. Probes under the ground clamp and by the drive wheel.

OCV
Setting 1 - 20.5
Setting 2 - 22.8
Setting 3 - 25.7
Setting 4 - 28.3

Welding voltage
Setting 1 - 16.9-17.2
Setting 2 - 17.55-17.7
Setting 3 - 19.28-19.43
Setting 4 - 20.9-20.92



I also swapped in the roll of .024 wire. I like it on the few beads I ran.

(Sorry about the pic. I have no idea why it looks lousy on the desktop but fine on my phone)