Welding Tips and Tricks

I have a Hobart Handler 120. I only have 4 heat ranges 1=18-24ga. 2=18ga. 3=11ga. And 4=max Wire speed is 1-10. How do I deal with voltage settings that call specifically for a certain voltage when I don't show it? I've had this welder for a while. Did I screw up buying this welder?

A welding recommendation chart, as from your wire's manufacturer, will often give single voltage and wire speed numbers for a given thickness, but a WPS for a job usually give you ranges for each. In both cases, it's "open circuit" voltage, and you can determine that number for each setting on your machine (It may even be in the specifications in an appendix of your manual, but you're better off measuring for yourself.

If you have access to a voltmeter, open the machine cover and disengage the wire-feeder tensioner or remove the wire. Clamp the neg- lead of the voltmeter in the machine's ground clamp, and put the pos+ lead of the meter on your welding tip. (You can do it in the cabinet on the terminals, as well, if they're exposed... Never opened that machine.) Voltmeter should be set for DC, of course, and start with a range of at least 30 V, though I don't expect that machine to go above 24 in "max".

Choose a range, squeeze the trigger (gas off, why waste it?) and record the voltage once it stabilizes.

Now you have guidelines to compare what you have to what you require.

If what you require falls close to one of your settings, it's an easy choice. If it falls right in the middle, you have to make a judgement call between "Slow, but pretty", and "Fast and deep". Only exerience will be able to guide you there.

Steve S

Thank you very much for the response, Steve S. and Otto N. Excellent suggestion.I will do that.

Steve, will that method give you actual welding voltage, or just the "unloaded" weld voltage (sort of like open circuit)? I thought you would have to have someone measure the voltage at the terminals inside the machie while you actually welded with it? Maybe it is just the "constant voltage" aspect of the power source and I didn't need to do it the hard way?
Thanks

For setting a MIG machine, it is the open circuit voltage you're looking for, and on a digital machine is the number displayed. During welding, you won't get an accurate reading as the voltmeter would be in parallel with the arc.

And, you're right, this works because of the "constant voltage" nature of the design.

Steve S

Otto Nobedder wrote:For setting a MIG machine, it is the open circuit voltage you're looking for, and on a digital machine is the number displayed.

Hi Steve,
Please help me to understand this. The open circuit voltage is what you read whem pulling the trigger, and reads a multimeter? My Sigma has a voltage reading, but i don't think it will kick in, if it cant establish an arc. Ie. the programmed hotstart sequence have to take place, before it will open or measure "actual power". When pulling the trigger, without ground, it will just feed wire out, at the speed it is set to (softstart-speed), not the programmed welding wire speed - Sorry for my english, is it understandable what i mean?

One think I don't understand is, that the datasheet for the machine does spec 69-76V open circuit voltage - Allmost all I tag is "spot-welded" to the table, i have never seen this problem with other machines. Any clues?

Data-sheet can be found here: http://www.migatronic.com/product%20fin ... mag/sigma2

Citroën

That is an MMA capable machine, and MMA appears to be the OCV (open-circuit voltage) given, which is typical. That's a very common OCV range for mma. In MMA mode, it will be a constant-current source. The OCV will vary, and the chosen (set-point) amperage will be displayed on the panel.

In MIG/MAG mode, it's the amperage that varies, with wire consumption, and the set-point (open-circuit) voltage will be displayed on the panel.

Admittedly, the website does not explain that in the "technical specs".

Steve S

Migatronic appears to be manufactured in India, explaining the rather impressive, though imperfect translation to British English.

Nowhere do I find a specification for MIG/MAG voltage ranges, only ultimate weld current. This appears to be an oversight in the literature.

For the Hobart 120:

I think that, for your particular welder, you would be better off using the method in the video linked below, instead of trying to set a specific voltage and wire speed.

http://www.youtube.com/watch?v=6eB9qnktmDI

I don't remember if he mentions it in the video, but NEVER adjust a tapped setting while welding, only adjust the continuously variable setting.

Arnolddyer.

You make a photocopy of the Diagram 2-3, Volt-Amp Curves; and the Chart 4-2 or 4-3, and keep close to your welding machine.
http://www.hobartwelders.com/om/6digit/o210088d_hob.pdf

You may want to add a few blank columns on the right hand side of those Charts, and jot down the welding parameters you use for a particular weld. Each horizontal line on those Charts is a excessively simplified welding procedure. Base metal thickness, brand of filler, diameter of filler, gas, gas flow, polarity, welding voltage range, amperage (wire speed), and ctwd (wire stick out). If you add a few more blank columns to the right of the chart, you can add other variables that you will want to use if you have to use that welding procedure again, at some future date. If you do take readings with a voltmeter and ammeter, you can jot down those amperage values in a column, the voltage values in a column, the number of the welding pass in another column, etc. etc.. With a few more columns, you can add even more variables. For example, type of pass (stringer, weave), temperature of base metal, cleaning method, etc. etc.. In that way you will have started to register the welding procedures that you have utilized.

Alexa

Otto Nobedder wrote:Migatronic appears to be manufactured in India, explaining the rather impressive, though imperfect translation to British English.

Nowhere do I find a specification for MIG/MAG voltage ranges, only ultimate weld current. This appears to be an oversight in the literature.

It's actually a Danish brand. I've been in the factory. Maybe some of the PCB's and programming is made in India.