Puddle Problem

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I end up running one of several machines in the plant and there is one that is really a pain. We've had the electrician check it out and I have exhausted my limited pool of tricks. The problem is that the puddle isn't stable, it jumps, spits, quivers and pops making a clean smooth bead impossible. Im concerned because we weld some componants that bare alot of weight when the product is fully assembled. With the way the machine is acting Im just not very confident in some of the welds. The machine is a Hobart Mega-Mig 650 with a Thermal Arc four wheel wire feeder running .045 solid wire with 98/2 on mild steel tube,sheet, and plate. Ive worked through the entire range of settings for voltage and fire speed, hotter makes the quivering more managable but its too hot for some situations. Wish I could give some pics or video but I went with the cheap cell phone and the wife won't let me play with the digital camera. Any ideas would be very appreciated because Im tired of fighting the thing.Ranger 250 GXTSmith Gas Axe
Reply:What's the voltage and WFS setting for the machine?Who makes the filler metal being used?When was the last time the drive roll tension was properly set?How old's the liner and contact tip in the gun?Have you put a voltmeter across the terminals and watched or recorded volts while someone is welding?These are the places I'd start looking for trouble.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:Meters not working but I know that the dial on the machine doesnt adjust properly, but i think its somewhere in the neighborhood of 25V and 5/6 on the wire feeder.Filler made by Kiswell in Korea.Drive rolls and new gun were my first attempts, no joy.Voltmeter is a thought. Thanks.Ranger 250 GXTSmith Gas Axe
Reply:The “several machines” they work correctly, are that the same as the maverick? Are you using the same wire all around? Compare the volts, wire feed speed?
Reply:Machines are various makes, my primary machine is a 300 amp very old Hobart with a TA 2 wheel feeder and it is smooth and adjusts accuratly throughout the range. I also run an older Lincoln R3S with a 4 wheel TA feeder some and it is also smooth and adjustable. All use the same wire filler and the gas is a plumbed manifold.Ranger 250 GXTSmith Gas Axe
Reply:Kiswell filler is a good brand, so I wouldn't look to hard there.  Doesn't sound like a gas problem to me...Check your voltage with a multi-meter.  Then take the gun and pull the trigger in the air  for 10 seconds.  Use a stop watch for time.  Measure the wire that comes out and watch for smooth wire feeding.  Measure the wire spit out of the gun, multiply by 6.  Take your voltage and WFS and double check against a filler metal chart.  Miller has one buried on their website if you need one.I'm thinking either your wire feed is stuttering for some reason, or you're not getting the volts you think you are.  Why either might be happening is still a mystery...Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:I think what A_DAB_will_do was suggesting is to have someone watch the voltage while the machine is being used, to see if it remains stable at one value, and is high enough. There are only so many things that can be wrong; a bad or fluctuating power supply, slipping drive rolls or wire dragging in the liner, worn brushes or bad bearings causing the drive motor to jerk rather than run at a steady speed, poor conductors (high resistance) between the power supply section and the gun tip.
Reply:I would swap feeders with one from another machine that is known to work good, so that way you can narrow down the problem to either a power supply problem or a feeder problem and then go from there with the volt/wfs experimenting.   Also, check all cable connections and cable conditions when you do the feeder swap.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Yes, look under the covers at all the connections. Measure the wire length for 6 seconds and multiply by 10 for the inch per minuet.Any chance that the input power [220 v] is sagging?Last edited by transit; 02-03-2010 at 11:23 PM.
Reply:Sounds like a gas problem, like a leak in the system feeding that machine, thus allowing air to enter, or some other issue with inadequate shielding.You said it yourself, "The problem is that the puddle isn't stable, it jumps, spits, quivers and pops making a clean smooth bead impossible."  So this makes me think cleanliness, like in having good inert gas shielding.  If you have a fairly stable arc, then your voltage and wire speed and contact tip and all are probably ok, so what would screw up the puddle?,  How about the gas.
Reply:I'm going to go in a different directions here. Saw this problem tonight in a more advanced welding class than I am in. One machine in particular was having problems at the same settings as all other machines. Everyone looked at the welder, gas line, reg, etc. Turns out the wires in the wall receptacle weren't tight. This gave a fluctuation in voltage. Check your receptacle and the power line for loose connections, fraying, etc. I am in NO way saying this IS the problem, but it is also worth a look if all else fails.
Reply:Turns out the wires in the wall receptacle weren't tight. This gave a fluctuation in voltage.
Reply:I had some good quality wire, that I paid top dollar for once, and could not wait to get through it, because it just wouldn't feed well in my feeder.  It seemed to have a good bit of spiral to it but I don't think that was the problem.  I think it was just that my drive rolls just didn't like it.  It would push and slip, push and slip making the arc unstable, popping and doing many things it shouldn't, similar to what your issue is.  My unit was nearly new at the time, but for what ever reason, it wouldn't feed, even after retensioning.   Finally got through that wire and haven't had any issues since.   But thinking about your situation, how worn are the drive rolls?  If they are worn or the tensioning is not right, then it could imitate some of the problems.But determining voltage under load is a good idea, as I have had that problem once, with a leg that had corroded at the terminal.  It would work fine until a little "work" was demanded from it, then it would go haywire.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:If the arc is unstable try to look at the first basic the contact tip if it is worn the wire spirals out causing erratic arc. Second check tension of the wire spool spring if too tight it stutters. Go through and clean everything new liner check for worn drive rolls. Possible could even be operator error holding the nozzel beyond the recommended distance of 3/4" which would create a drop in voltage and without adjusting the amps (WFS) you would get a great deal of spatter.  Try these things if that doesn't work get a welding machine rep out there it might be internal problem.Weldor/ Certified Inspector
Reply:Originally Posted by MrLeadManI end up running one of several machines in the plant and there is one that is really a pain. We've had the electrician check it out and I have exhausted my limited pool of tricks. The problem is that the puddle isn't stable, it jumps, spits, quivers and pops making a clean smooth bead impossible. Im concerned because we weld some componants that bare alot of weight when the product is fully assembled. With the way the machine is acting Im just not very confident in some of the welds. The machine is a Hobart Mega-Mig 650 with a Thermal Arc four wheel wire feeder running .045 solid wire with 98/2 on mild steel tube,sheet, and plate. Ive worked through the entire range of settings for voltage and fire speed, hotter makes the quivering more managable but its too hot for some situations. Wish I could give some pics or video but I went with the cheap cell phone and the wife won't let me play with the digital camera. Any ideas would be very appreciated because Im tired of fighting the thing.
Reply:Originally Posted by Oldiron2Yes, and that will show up if the output voltage is measured while the machine is running and being used. Why is determined afterward.Any signs of excess heat in that box?
Reply:Resolved this problem today. Had the electrician swap the problem machine for a power source that wasn't in use. I can fine tune whatever setting I want, even spray arc, smooth as silk.Ranger 250 GXTSmith Gas Axe