Mig on constant current welding machine?

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Nothing better to do today, so I thought I'd play around. Ran these with my 1966 SA-200, (no CV box), and LN-25. .045 wire, about 20 cfh of C25. Little more splatter than I'd like to see, but that might be the generic wire my LWS sold me. With some Lincoln wire maybe there would be less splatter. Never done this before, so what do you think? Attached ImagesLast edited by zapster; 01-26-2012 at 01:35 PM.Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:I played around with constant current and found no big problems using a CC power source and suitcase feeder.  That is until I tried .035  hard wire.  I had starting problems and the feed was erratic.  I asked around and I was told that it was typical.  The motor drives could not respond fast enough with smaller wires.
Reply:What settings? Large wire / high amp settings usually will work with a VS feeder on CC. Looks like you were probably getting up into globular with that 1st bead and were out of short arc where most of the issues occur. With C25 you had to much CO2 to really be in spray. FC up in spray will work OK as well. The issue is when you move down to small wire and try to run at lower outputs. As mentioned above the motors usually can't respond fast enough to mimic CV. This makes mig on "thin" material a PITA. Material below say 1/4" that's usually the main "bread and butter" of what most people are thinking about when you say "mig".1st bead looks ok, I see a few small issues with the middle third. Looks like you might have increased your stickout there a bit making it run a tad colder than the rest. The 2nd pict, looks like either you aimed the top bead too high on the upper plate, or you ran colder on that pass for some reason, my guess would tend towards increased stickout if you didn't change any settings. It's the "worst" of the lot. Consistancy looks fairly good. The bead looks slightly thinner in the middle to 1st third, but that might just be an illusion based on the fact it's a bit higher than the lower bead and didn't tie in at the bottom.  Lower bead, second pict looks a bit erratic. Hard to really see much with the bead covering part of it. The left end looks ok. The middle looks a bit cold in spots. Could be an optical illusion, might be erratic travel speed or motion if you were moving the gun in a zigzag pattern, or it might be small changes in stickout as you moved the gun. Far right looks hot and rushed to some degree. It almost looks like you stopped 1/3rd of the way along and turned down the machine and ran the last 2/3rds. If so your tie in needs a bit of work, but it's better than many I've seen.A lot of the above is nit picking. I tend to be a perfectionist with a lot of this sort of stuff and pick up little tiny errors, probably as a result of helping guys learn regularly. Kind of hard to tell in the picts. Are these done in 1F or 2F out of curiosity?.No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Originally Posted by DSWA lot of the above is nit picking.
Reply:I always get these pictures mixed up, and forget what I did between the shop and house. But here is another picture. Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:I found similar results.  With big stuff, it worked ok,. but ...LIFE is better with CVDavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:they look great is that dual shield ..........i use my 12 vs extreme on a cc machine with flux core it does a great job i run .045 lincoln Nr-211Lincoln Power Arc 4000 Thermal Arc Fabricator 252 iThermal arc 186Thermal Arc 26 tigTweeko 200 amp spool gunHobart AirForce 400WP-17V-12R
Reply:Originally Posted by assassin_worksthey look great is that dual shield ..........i use my 12 vs extreme on a cc machine with flux core it does a great job i run .045 lincoln Nr-211
Reply:Originally Posted by David RIts bare wire with C/25.    Nice welds.How many inches per minute of .045?David
Reply:I was asking the original poster.   The hotter I run on VV, t he better things weld until I get into globular. then everything goes to sh*t from spatter etc.assassin_works  Check again.  115 inches per minute should be 115 amps of bare .045 wire with normal stick out.Lincoln handbook of arcwelding says 150 ipm = 165  amps.  It comes out closer to 150 for me.This has nothing to do with your welds. just discussion of amp draw and wire size.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:I'll have to check the LN-25 when I head out to the shop, I don't think I changed anything. I'm from the era of just turn knobs / dials until I get the results I want. These new machines with digital gauges areDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Changed over to some .035 wire this morning. Switched the LN-25 to high speed, and set it at 380. Where as yesterday the LN-25 was set on low speed at 260. Didn't touch the SA-200, but turned the remote down to 35. Same amount of C25. I have to say I don't see a whole lot of difference than any other Mig machine I've run, except I didn't pin the R-57 idler in the high idle position, so it takes a split second for the welder to come up to rpm. Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Lincoln L56 is THE best for pulsed spray for me.  A true premium wire.  Next is ESABReal world weldin.  When I grow up I want to be a tig weldor.
Reply:Originally Posted by David RI was asking the original poster.   The hotter I run on VV, t he better things weld until I get into globular. then everything goes to sh*t from spatter etc.assassin_works  Check again.  115 inches per minute should be 115 amps of bare .045 wire with normal stick out.Lincoln handbook of arcwelding says 150 ipm = 165  amps.  It comes out closer to 150 for me.This has nothing to do with your welds. just discussion of amp draw and wire size.David
Reply:Yes, I get it.  Original poster is using bare wire and that is what I am talking about.  You are using NR211.  Whole different ball game.Go here and look up .250" plate welded with .045 bare wire.  It suggests 235-245  ipm and is about 220 - 225 amps.http://www.esabna.com/EUWeb/MIG_handbook/592mig12_9.htmCEP  260 ipm of .045 is ABOUT 260 amps.  Cooking right along.380 of .035 should be about (380/1.6) 237.5 amps.  Still pretty hot.ON VV my LN-25 does not read out the same on the dial as CV.  I need to look at the chart in the door.  Its at work, I'm at home.My numbers are probably off.DavidLast edited by David R; 01-27-2012 at 07:32 PM.Real world weldin.  When I grow up I want to be a tig weldor.
Reply:Originally Posted by David RCEP  260 ipm of .045 is ABOUT 260 amps.  Cooking right along.380 of .035 should be about (380/1.6) 237.5 amps.  Still pretty hot.
Reply:I realize you all are working on the big stuff, but would MIG on a CC machine work at lower power (like down to 22 ga) if one ran the feeder off a separate, stable power supply? Are CC MIG issues simply erratic wire speed related??Seems like it would be trivial to plug in an off the shelf 110V>24V power supply to run the feeder running off aux power.(Thinking spoolgun on a PWM supply I built, it will run on 110/220 or ~28v depending on how I hook it up, wire speed control pot on gun, voltage control easily added )Last edited by waferhead; 01-27-2012 at 09:24 PM.
Reply:22 GA!!!  I hope you're not asking me! I'm a structural weldor I don't think I could Tig weld 22GA! Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Originally Posted by waferhead Are CC MIG issues simply erratic wire speed related??
Reply:Thank you for the excellent explanation.I kinda understood, but I visualized it was just to deal with the varying voltage the feeders were running off of.So in order to do it effectively you would need a servo control loop.On a TIG supply with a remote in you could probably electronically vary the "pedal" input fast enough to help as well.(would probably require a machine that can take an external pulser, but ...)Might be easier to do on a spoolgun due to low spool/wire mass.(I can't help myself playing with this sort of stuff, used to be my real job)Last edited by waferhead; 01-27-2012 at 10:28 PM.1999 Synchrowave 250, Bernard cooler.TA 181i, US version, with TA 181i Euro connector, Euro on torch.Firepower spool gun w/Euro connector, modded to suit 181iPressure controlled TIG amptrols.TD PacMaster 100XL plasma cutter