Pulse MIG welding question

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I have been trying to get used to working with Pulse MIG on my Multimatic 255. My question is, is it bad to do gun manipulation while welding in pulse mode? I read one article from ESAB that said gun manipulation could result in a less than ideal weld because the welding machine might not adjust fast enough to the changing arc length from moving back over the bead. My journey with pulsed MIG has kind of gone as follows: I started out with 1/8th coupons (cold rolled steel, no mill scale) and 0.035 wire (Lincoln L56), using the autoset feature, and 90/10 gas. At first I was getting a whole bunch of spatter and really crappy looking beads that were all strung out. After a while I figured out the correct stick out, but the beads were still pretty inconsistent, really thin and I was still getting a lot of crackling and spatter. Next I spent time figuring out the best combinations of wire feed speed and arc length. I was running 155 on the WFS (up from the recommended 150) and an arc length (trim) of 60-67 (out of 100, with the default being 50). Finally I started making some halfway decent beads with no spatter, but I couldn't get the puddle width I wanted for a fillet weld, and was still having trouble with holding a consistent puddle width. I then switched to 0.045 wire (still L56), and the situation got significantly better. But I was still having some trouble getting decent leg size on fillet welds, so I started experimenting with using the cursive "e" technique I normally use on short circuit MIG. There was a tiny bit of crackling and spatter on the back end of the "e" when I transition across the middle, but the beads looked much improvedThen I transitioned over to 1/4 inch CRS coupons and this welder really came to life! Man, this process is HOT. On 1/4 inch material, all of the autoset settings were almost perfect (150 WFS and 50 arc length). I could make OK beads with plenty of bead width with a straight push (all of my work has been pushing, not pulling), but when I kicked in the cursive "e" the beads came out much better. So, what am I doing wrong and is gun manipulation a no-no?Once I get better at this, I will need to do some cut and etch samples. Its crazy how much hotter pulse is over short circuit. Almost feels like dual shield hot.Miller Multimatic 255
Reply:Subscribed.Millermatic 255Dynasty 280 DXReady Welder IHypertherm 30XP
Reply:I didn't really like the Miller XMT/Optima pulse on steel. It looked OK but wasn't any benefit over straight spray or short-arc transfer, penetration was marginal. I kept the optima pulser for aluminium only.the Lorch Saprom I have now is far better on steel for pulsing, I use it for structural sections and anything over 3mm, although I'll switch to short-arc for uphill.The general rule of thumb I was told by the Lorch guys themselves, was to alter the arc length until it's about 1mm above the weld pool. You'll still get a few crackles but it should be mostly straight humming/buzzing. I run as much wirespeed as I would normally run for the thickness of steel, that makes sure your average amps are up where they need to be and keeps travel speed up a bit. It IS a slower process than straight CV spray. It's also a very runny puddle at higher amps. Say anything above 100 amps, the puddle is too runny to work in anything other than flat and 2F positions. I know some people get it to work for them, but I personally can't, so i switch to short-arc.as far as manipulation goes, the pulse puddle wants to make a very flat fillet weld, I think due to surface tension as the puddle freezes. So any side to side manipulation leads to variations, and you can get undercut, bad tie-ins and even cold laps.I move, pause, move, pause. The arc goes direct in the middle of the joint, and I pause until the sides are filled, then move forward. This is where you really need enough wirespeed to fill the joint at a decent rate, without putting too much wasteful heat into it.It's not the same as the CV arc, you have to let the machine do the welding. My brother has my old XMT now and we've been welding together over the last few months. He's got used to the CV arc and I've got used to the pulse arc. I can use his machine and make a nice CV weld, but for some reason he can't use my machine and make a nice pulse weld. He overthinks and over manipulates it and it makes a mess.I've proved the Lorch settings on cut+etches, and now I treat my machine's torch like an "idiot gun" - I set material amps, pull the trigger and just squirt metal into the joint

Murphy's Golden Rule: Whoever has the gold, makes the rules.
Reply:The pulse spray can stumble if your arc length changes, which it does if you are manipulating at a speed that is needed to prevent over reinforcement. A straight line push is best.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:On Millers spray arc machines, their main pulse process is called accu-pulse. It is considered a pulse CV hybrid. Of course you can do short circuit with it as well. Lincoln's pulse process was called Rapidarc, it could have changed by now. They are similar in application but Miller utilizes a feedback cable to control weld parameters in real time. Lincoln claims that their feedback is attained from the input and output of the welder. Without this information there is little room for error in pulse technique. Both of the hybrid pulse processes on these machines is awesome. It is smooth and clean after learning the basic techniques. It is usually taught to keep the arc at the root of the weld with a 1/4-1/2 wire stickout. Manipulation is to be kept at a mimimum (i teach a sewing machine stitch, 1/16-1/8 back and forth from the leading edge of the weld pool). Old school pulse (which is what it sounds like your running) is more difficult to manipulate. Years ago my company tried to get us all to switch to a straight pulse spray. Eventually most welders went back to CV... until they rolled out the hybrid processes.Lincoln 275 SquarewaveLincoln SP 250
Reply:The welder is the Miller Multimatic 255. The machine was just released recently (last year?). There is no feedback or voltage sensing cable. Think of this as a smaller version of the Millermatic 350P. This machine is similar to the millermatic 252 (more or less) but adds pulse and couple of other features. https://www.millerwelds.com/equipmen...-welder-m30175Miller Multimatic 255
Reply:The settings for 035 wire on 1/8" steel seem off (for WFS) IMO.  Question:  When you adjust the arc length/trim, aside from the arbitrary 0-100 scale that it uses, can you see the actual effect on the voltage somewhere on the screen?  In other words, what I'm asking and trying to get at is:   do you know your actual & final welding voltage setting after adjusting the trim, and if so what is it?

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Reply:

Originally Posted by Oscar

The settings for 035 wire on 1/8" steel seem off (for WFS) IMO.  Question:  When you adjust the arc length/trim, aside from the arbitrary 0-100 scale that it uses, can you see the actual effect on the voltage somewhere on the screen?  In other words, what I'm asking and trying to get at is:   do you know your actual & final welding voltage setting after adjusting the trim, and if so what is it?
Reply:

Originally Posted by Louie1961

I usually don't get my hood off fast enough to catch the actual voltage. I'll have to see if there is a setting the lengthen the delay. I also mixed up some numbers. WFS was in the 275 range on .035 and 150 range on .045 for the 1/8th coupons. At 1/4 inch I was pushing around 250 IPM on the 045 wire
Reply:What's your theory?Miller Multimatic 255
Reply:that maybe the settings have been extrapolated from other synergic programs

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Reply:From what i read, you only have two parameters to adjust on the MM255 - wire speed and arc length. This is the same as all earlier Miller pulsed machines.The later Invisions and 350P all have an additional parameter to control, called "sharp arc" which sets the dynamics of the arc. I've never used it but I imagine it makes the pulse on steel a lot nicer. Reading between the lines, this is the 3rd generation of Miller pulse. (1st gen was manually set, 2nd generation had an auto arc length control)As Zebediah says, the 1st and 2nd generation pulse processes aren't any better on steel than straight CV, but the newer hybrid pulse programs do offer some advantages.If you can't get a machine to run great on steel pulse, don't worry - you haven't missed out on much! And any pulse on aluminium is good IMHO

Last edited by Munkul; 2 Days Ago at 03:38 AM.Murphy's Golden Rule: Whoever has the gold, makes the rules.
Reply:

Originally Posted by Munkul

From what i read, you only have two parameters to adjust on the MM255 - wire speed and arc length. This is the same as all earlier Miller pulsed machines.
Reply:I just checked..all the same pulse MIG adjustments as the 350P. They even call the sharp arc feature "arc control" now in the latest version of the 350P owners manualMiller Multimatic 255
Reply:Ah OK, that's cool.I dunno about running like dualshield - normal pulse on steel runs like hard wire spray, it's not positional... Steel just doesn't freeze fast enough unless it's a modified pulse for rooting or uphill. Aluminium does though. Running pulse on aluminium makes you feel like a hero. Upside down, inside out, whatever you like, it freezes fast and looks great!Murphy's Golden Rule: Whoever has the gold, makes the rules.
Reply:

Originally Posted by Munkul

The later Invisions and 350P all have an additional parameter to control, called "sharp arc" which sets the dynamics of the arc.
Reply:I have never used pulse welder.I only used the trigger and did pulse.It would interesting to try a pulse welder , save the finger 😉. Dave

Originally Posted by Louie1961

I have been trying to get used to working with Pulse MIG on my Multimatic 255. My question is, is it bad to do gun manipulation while welding in pulse mode? I read one article from ESAB that said gun manipulation could result in a less than ideal weld because the welding machine might not adjust fast enough to the changing arc length from moving back over the bead. My journey with pulsed MIG has kind of gone as follows: I started out with 1/8th coupons (cold rolled steel, no mill scale) and 0.035 wire (Lincoln L56), using the autoset feature, and 90/10 gas. At first I was getting a whole bunch of spatter and really crappy looking beads that were all strung out. After a while I figured out the correct stick out, but the beads were still pretty inconsistent, really thin and I was still getting a lot of crackling and spatter. Next I spent time figuring out the best combinations of wire feed speed and arc length. I was running 155 on the WFS (up from the recommended 150) and an arc length (trim) of 60-67 (out of 100, with the default being 50). Finally I started making some halfway decent beads with no spatter, but I couldn't get the puddle width I wanted for a fillet weld, and was still having trouble with holding a consistent puddle width. I then switched to 0.045 wire (still L56), and the situation got significantly better. But I was still having some trouble getting decent leg size on fillet welds, so I started experimenting with using the cursive "e" technique I normally use on short circuit MIG. There was a tiny bit of crackling and spatter on the back end of the "e" when I transition across the middle, but the beads looked much improvedThen I transitioned over to 1/4 inch CRS coupons and this welder really came to life! Man, this process is HOT. On 1/4 inch material, all of the autoset settings were almost perfect (150 WFS and 50 arc length). I could make OK beads with plenty of bead width with a straight push (all of my work has been pushing, not pulling), but when I kicked in the cursive "e" the beads came out much better. So, what am I doing wrong and is gun manipulation a no-no?Once I get better at this, I will need to do some cut and etch samples. Its crazy how much hotter pulse is over short circuit. Almost feels like dual shield hot.
Reply:

Originally Posted by smithdoor

I have never used pulse welder.I only used the trigger and did pulse.It would interesting to try a pulse welder , save the finger . Dave
Reply:It looks great But my old work was plate.Still try pulse it looks great. FYI The chip that makes the pulse was first made 1960's (CI 555) It one of most widely used chip. Dave

Originally Posted by Louie1961

This is completely different so save your finger anyway. This is like changing the voltage knob hundreds of times per second.
Reply:From the manual,C. Weld StatusWhen trigger is released on a MIG gun, spool gun, or push-pull gun, the last actual amperage and voltage are shown on the display for 5 seconds. If aprogrammed value requires adjustment after the arc is extinguished and during the 5-second display of actual values, turning either knob will causeactual values in the displays to be replaced by programmed values for adjustment purposes