Welding inductance question

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I have noticed over the years some of the posters promoting the virtues of being able to adjust the welding inductance for MIG welding.  As I understand it, Miller and Lincoln generally do not offer this option, while ESAB and Thermal Arc generally do offer adjustable inductance.I was demoing a Thermal Arc 252i, and the factory guy explained that more inductance tends to mean more penetration.  On one bead he did adjust the inductance while I was welding, and it did seem to make more noise and penetrate better.  Not sure if it also had more splatter or not.So what does inductance mean to you?  What would cause you to change it from the factory suggested setting?RichardSculptures in copper and other metalshttp://www.fergusonsculpture.comSyncrowave 200 Millermatic 211Readywelder spoolgunHypertherm 600 plasma cutterThermal Arc GMS300 Victor OA torchHomemade Blacksmith propane forge
Reply:Inductance control is not unique to ESAB or Thermal Arc.  Miller and Lincoln's higher end machines have inductance control as well.Wikipedia has a nice discussion about inductors.http://en.wikipedia.org/wiki/Inductorbut the pertainent quote is this:  "...Thus inductors oppose changes in current through them."An inductor in the welding circuit smooths out spikes and drop outs, making for a smoother arc, and as a result, a smoother, less turbulent puddle.In physical terms adjusting the inductance on a welding machine adjusts how large a droplet of molten metal transfers from the end of the wire to the weld pool. There are other things changing with a change in inductance.  But this is one of the important ones.The smoother the arc, the smoother the transfer of droplets into the puddle, the more uniform the penetration.  A smooth puddle also reduces the chances of cold lap; where molten metal spashes around and freezes without really fusing to the base metal being welded.Inductance is most effective with short circuit transfer.  I don't think it's relevant to spray arc transfer, but someone else who's played with it more than I may contradict me.  It's of less value with FCAW welding, since lots of other things(flux chemistry, particle size, moisture content,etc) influence how droplets of molten filler metal transfer across the arc.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:http://www.esabna.com/EUWeb/AWTC/Lesson2_22.htmEd Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:Actually, it's mostly the other way around: more inductance = a softer arc, wetter bead, less spatter. Less inductance = harsher, tightly-focused arc, narrower bead profile, more spatter but better out-of-position.Like A_Dab_Will_Do pointed out, only matters in short-circuit transfer mode, inductance has no effect in spray transfer.Whether you can control inductance or not has to do with the electronics of the welder. Inverters generally offer continuous control. Transformer-type welders do not but some have multiple taps for different amounts of inductance.BTW, I tried out the T/A 252i last year at Fabtech. Really nice machine. I was impressed.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:I can tell you that inductance also known as "arc force" in Lincoln electric speak makes a real big difference when running self shielded T-8 electrodes.Vantage 500's LN-25's, VI-400's, cobramatics, Miller migs, synch 350 LX, Powcon inverters, XMT's, 250 Ton Acurrpress 12' brake, 1/4" 10' Atlantic shear,Koikie plasma table W/ esab plasmas. marvel & hyd-mech saws, pirrana & metal muncher punches.