Welding Tips and Tricks Rule of 33 and a T/A 186

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I have been trying to figure  out this concept with my T/A 186. I get the 33pps is the Pulse Freq, the 33% on time is the Pulse Width, but cant figure out the 33% background. I think I am just misunderstanding what this is. Can someone please explain the Background setting on the T/A 186.Thanks
Reply:The background percentage number represents the amperage on the "low part" of the pulse--but not in absolute terms of amperage, but rather a percentage of the weld current.  33% means the low part of the pulse will be 1/3 of whatever the high portion is.  IE:  if the on-time weld amperage is 100A, a 33% background current means you'll have 33A on the low portion. 1st on WeldingWeb to have a scrolling sig! HTP Invertig 400HTP Invertig 221HTP ProPulse 300HTP ProPulse 200 x2HTP ProPulse 220MTSHTP Inverarc 200TLP HTP Microcut 875SC
Reply:As a guy with a TA 186, I could use a lot of clarification on this. It's been on the back burner of things I need to figure out, but since we're all here..I am new to TIG, and I can't figure out how to apply the rule of 33 to the TA 186 either. Seems Jodys machines all have settings that differ greatly, IE pps vs hz, etc.I am not well versed in this stuff, I am going to night school to improve my general understanding of TIG, and practicing at home, but if anyone wants to dumb this whole situation down so it's more easily understood, I'd be appreciative.If you fight long enough, you will win. The problem is it costs too damned much.- Lee Cheng
Reply:IIRC Thermal Arc machines display the background current as an amperage value and not a percentage. So if you are welding @ 66A peak current and set your background to 33 this would be 50% background current. For 33% you would want to set the background current to 22 amps which is 1/3 or 33% of the peak 66 amp setting.That is how my TA200 displays pulse. I have never used the 186 so I can say for sure, but if it isn't a percentage there's not a whole lot else. I believe the display identifies which value is being adjusted i.e. Amps, seconds, % or Hz (frequency). Like I said I've never used a 186 but I'm sure it shows you what you are adjusting, try looking at the display...Pulse Frequency = Hertz (Hz), Pulses Per Second (PPS), same thingOn Time = amount of time spent on peak amps, set as % on any machine I've usedPeak Current = self explanatory, set in ampsBackground Current = The low end, set in amps or as a % of the peak ampsPulse can be very useful once you get it figured out. Best thing to do is just play with it when you can and see what you like the best. I don't like 33pps, I prefer around 50 or above and 20% background. 33pps is like a friggin helicopter to me I knew right away I hated it haha. Everyone's different, poor Jody has to try to figure out something for unknown thousands of youtubers. 33s is a good place to start. Best of luck - Rgfab
Reply:RGFAB is correct.On the TA186 to set up for the "rule of 33" you would set:High Current  X       AmpsWidth           33 %  (this means 33%  of each pulse is high current)Frequency    33 Hz (Hz is another way of saying per second, in this case pulses per second)Low Current .33 x X Amps (You need to do the math, multiply High Current by 0.33 and round to the nearest amp)If you are doing AC  you will set the AC frequency in Hz (in this case cycles per second) and the Wave Balance in %.  Those two parameters are not part of the rule of 33.  Set them the same as you would if not doing pulse.  Try 60 hz and 30 % EP for starters.  In general going down in Hz will give more penetration and wider arc.  Going down in % EP also gives more penetration and less cleaning action.Miller and a lot of other makes does AC balance backwards of Thermalarc.  They display the % EN and so generally suggest starting at 70%EN which is the same as 30%EP.
Reply:Thanks Fern,After thinking about it I thought that since you set the high and low amps in the pulse mode there was math involved.
Reply:Thank you.And I had already mastered the art of looking at the display, it's the bits beyond it that confused me. I can't follow the electrons across the PCB.'preciate it.If you fight long enough, you will win. The problem is it costs too damned much.- Lee Cheng
Reply:FernTJ, my understanding of TIG AC, High Frequency above 60Hz seems different than what you've posted. "In general going down in Hz will give more penetration and wider arc. "I fully agree the lower Hz of the AC will widen the arc where 60Hz is the 'old fashioned' 90 degree arc cone, but the idea this provides a MORE penetration is completely contrary to my experiments, welding and experience with the Miller 300DX TIG power supply.My experience shows and break bend tests confirm that the puddle width and penetration are hand in hand, as the arc cone narrows with higher and higher frequencies I find more and more penetration. Likewise I find that as the puddle widen with a wider arc cone from a slower frequency AC occilation so does the penetration become more surface and less below the surface.But I'm more than willing to learn new TIG info. What concept explains a wider arc cone provide a deeper arc core penetration?  My experiments with the Miller shows the depth of penetration at 250Hz is twice to three times as deep as at 60Hz with the same parent metal, same joint, same tungsten and same power settings.Could you explain the statement so we can clarify this?  I do agree the Balance (% neg sine wave time) also impacts penetration so perhaps my experiments were influenced by the balance and not the arc cone foot print as I'd thought?  I was focused on a T fillet using beveled plate on a flat T surface (inside fillet). The results were very dramatic where the higher the frequency the greater the depth of wetted root face and the lower the high freq. the less root wetting was achieved.Next, we did butt joints, beveled and square edge and again the higher freq the narrower arc cone footprint the narrow the bead, and the deeper the weld.  Of course we used the Miller as the old Lincoln 300/300 didn't have any arc controls so we were confined to fixed Hi freq @ 60Hz. Not a bad weld, and it built hundreds of skiffs, but not the control provided by the Miller.Would like to more fully understand your welding results?Cheers,Kevin MorinKenai, AK
Reply:If u r new to TIG, leave Pulse off!    Set htz between 100 and 120 and u r good to go.   Pulse will help with discoloration control on stainless.  But everything else u r better learning to weld without it.  Sent from my SPH-D700 using Tapatalk 2Tiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:SouthPaw is 110% correct here.  Leave it off until you get really good with basic TIG. Nothing worse to hamper your learning curve than trying to mess it up with pulse.Jody's done a lot of reviews on our equipment.  We've talked quite a bit.   However, I'd disagree with him on the settings, or the rules of 3.  That is what he has found to be optimum for him. He's not wrong, but it's his opinion....from an expert point of view, with expert skills... But I find that most people initially think in equal terms, or balanced settings. This means setting the pulse balance (time on/pulse width) to 50% and setting Pulse amps to 50% or roughly half of the peak (high stage of pulse) amps.  Then setting pulse to around a controllable, natural rate of 1 pulse per second (hertz).   If you are pulsing, most people are going to use the pulse to manually time the dips, to enhance the appearance. This is why I recommend our customers to use 1 hertz if they want to use it at first, because it helps keep things even and on a steady keel.  It's easy to synch up a 1001, 1002 count with a 1 second pulse every time you want to dip...or some similar pulse setting, even a 2 hertz  is manageable if you are proceeding rapidly.  The even, 50/50 setting keeps   each part of the pulse equal in length allow the half pulse cycles to be even as well.  Keeping it off balance at 33% or so, keeps your timing off balance at first.The 33 hertz is sort of an arbitrary number, though as the pulse frequency when used in the higher range produces a different sort of effect, or rather should I say, and increased effect.  Even that is going to depend upon what effect you are looking for.   For a medium pulse, I'd rather see someone set the pulse at 50-100, hertz.Last edited by lugweld; 09-02-2013 at 11:07 AM.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:Thermal-arc picked these # on their older 300  GTSW  Great machine too.  Pulse width is fixed at 35%.Background current is fixed at 1/5th of the peak current.Esab/Lorch ET-220iEsab 160i caddyThermal LM-200 Lincoln feedersThermal Pee-Wee 85sThermal 60i- 3phase /RPC powered (Beast)Thermal Drag-gun 35CINE 1500 Klutch 140i