Help with mig welder (or operator!)

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I'm a newby, trying to learn basic MIG/FCAW for home/hobby purposes. Read the manual, watched some videos. Man, this is more difficult than I thought!! In any event, I'm having some problems and I wanted to ask if they were operator error or a machine issue.I'm using a Hobart 140 (latest model with 5 taps) and Lincoln flux core 0.30 wire. I'm welding 3/16 steel using the settings recommended on the door. However, during welding the arc seems to stall for a fraction of a second periodically (somewhat regularly, like an out-of-sync sputter). The wire is NOT bottoming out in the pool. While this is happening, I can hear the wire drive speed fluctuating. I think that the  wire speed fluctuation is causing a loss of arc when it slows down. You can practically see the arc moving back and forth between the work and the tip with the wire speed oscillation. HOWEVER, if I go to a short stick-out (3/16" or less) the issue improves noticeably (and the sound of the wire drive smooths out, too).I've checked the drive roller tension, and I can easily curl the wire against a wood block as illustrated in the manual. While doing so the wire speed is nice and smooth, without variation.Any suggestions? Is it me or the machine?Any help would be greatly appreciated.BeufordLast edited by Beuford; 02-27-2016 at 12:04 AM.
Reply:Does the wire have teeth marks from the rollers when it comes out? You may have the roller tension too high if so, and that can cause friction. Also check to see while dry running it if you feel any vibrations pulsing in the cable, and hold the gun at different angles to see if that induces any vibrations. If you feel any of that, you are getting some friction somewhere in the lining and may need to replace it, especially if you can induce it bending the gun in certain directions. Another trick would be to go up one size on the contact tip.
Reply:Originally Posted by TheBFADoes the wire have teeth marks from the rollers when it comes out? You may have the roller tension too high if so, and that can cause friction. Also check to see while dry running it if you feel any vibrations pulsing in the cable, and hold the gun at different angles to see if that induces any vibrations. If you feel any of that, you are getting some friction somewhere in the lining and may need to replace it, especially if you can induce it bending the gun in certain directions. Another trick would be to go up one size on the contact tip.
Reply:You might have a dirty or burned out tip or the wire speed is set to fast.
Reply:Maintaining a constant tip to work distance is very important.  Usually gasless flux cored wire requires a little longer stick out than regular mig welding, about 1/2 to 3/4".
Reply:Fluxcore wire is a hollow tube. If you  apply to much drive roll spring tension it can deform the wire, making it difficult for the wire to feed smoothly through the round bore of the contact tip.The 140 wire drive circuitry is feed from the arc voltage, so if you have a poor work clamp connection this could result in the wire feed and arc being erratic.Another poor electrical connection that can exist would be between the wire drive housing and the power pin of the gun assembly. Check the tightness of the thumb screw on the wire drive housing.ESAB Migmaster 250 Hobart Ironman 230Multimatic 215TWECO Fabricator 181i & 211iHH125EZ - nice little fluxcore only unitMaxstar 150 STH - very nice
Reply:Originally Posted by BeufordThere are no teeth marks on the wire, but it has sufficient tension to curl the wire against a wood block. The wire does not skip or alter in speed except when actually welding. You can hear the motor speed fluctuate - it really sounds like the drive mechanism is low on voltage during welding (maybe a poor connection drops voltage too much during welding?).I used my other welder (a Hobart 210MVP, in 120V mode), again with the settings found on the cover except with 0.35 flux core wire, and had no problem (although my welds still suck - I've got a ways to go...).Before you ask, one of the welders was a gift. I want to run the 140 when using 120V power because it is more adjustable at that voltage. I will use the 210MVP when I need to weld heavier materials, but I need to use it with a generator when running 220V since I don't have 220V power in the garage.Beuford
Reply:Do you have the correct polarity ?    POLARITY   DCEP  Electrode Positive  for Solid WireDCEN  Electrode Negative  for Flux-Cored  Wire
Reply:Ok, let me try to answer all the responses all at once:1) Not a drive roller tension issue. Set and tested by the book; try different tensions anyway - no change.2) Replace the tip (twice); no effect.3) Can't do longer stick out - the problem only gets worse.4) Wire speed is not too fast - it does not push back at all; the wire speed just slows down and fluctuates.5) Used the 210MVP in 120V mode on exact same circuit without any issues.6) Machine is new - maybe 20 mins of use total.7) I tried bumping up the wire speed, but then it did start to bottom out in the pool.This morning I tried again and it worked fine for a few minutes an then started to act up as before. I'm convinced now that it is a problem with the control board, so I returned it for refund (I wanted another, but they were out. Policy is refund if replacement not available).Thank you all for your input. I wish we had figured it out - I would really like to know the cause before I buy another!FWIW, I'm very happy with the Hobart 210MVP.BeufordLast edited by Beuford; 02-27-2016 at 02:44 PM.
Reply:This might be a case to contact tech support.  Since it's new and still under warranty.  ( a presumption)  The manufacturer should be responsible for getting it to work.Last edited by Robert37160; 03-03-2016 at 05:23 PM.
Reply:You may have described your solution.  When you went to the 3/8 stick out everything improved.  When you shorten then tip to work distance, you are shortening the arc length which is in effect, lowering your arc voltage.  If you had a voltage control dial, you would achieve the same effect by turning your voltage down .5 to 1 volt.  Gas less flux cored wire is all about proper stick out, and with 030 that 3/8 stick out may be just the right distance.