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I have the 325ext and get by without pulse most of the time. When I do need pulse I usually hit Google for some insight and come up short. I guess and try this or that and eventually turn it off lol. Could anyone share some basic pulse settings that work well for them? I've got some .040 stainless projects and some 3/32" and 1/8" 5053 (I think) projects. I've got purple and gold tungstens.
For the .040, to control heat input, try around 30-50 for pulses per second, background current, and duty cycle. For the thicker stuff I wouldn't use pulse at all. However, some people like to use a slow pulse to keep their timing and travel speed consistent. For that application dial the pulses per second to match your desired dip rate, around .5 to 4 pulses per second. Then dial down the background current and duty cycle just enough to you can clearly see the timing.
Some time ago,,, I decided to "play around" with pulsing and did some experimenting by making a triangle of Alum (with a wider base) so I had a Lap Joint and an Inside Corner and an Outside Corner. I played around with 1/2dz pieces like that maybe 8" long with all kinds of different settings. Because it was a complicated thing to try to evaluate, I took Notes so I could remind myself of what I thought about it all ;)
I share them, and any understanding I had or THOUGHT I HAD, below ~hehe
---------------------My Pulse Experience w/PP256 w/Alum Sheet Metal (22ga)--------------------------------
First you set the Main Amperage (High Amps)
OK, so then you've got those 3 knobs
Pulse Rate - how Fast to pulse in 2 Ranges (low/hi) ~ used 1-2 in LOW and 20-30 in HIGH
(Low) Pulse Amps (aka "background") - how far Down, as a percentage of the Main Amp setting, the low side Amps drops to during the pulse.
Time ON (balance) - how Long the pulse stays "hot" (at that Main Amp setting)
Main Amps have to be adjusted for the pulse settings. If you would need 50A normally and had a 50% background it should be set to 75A and the pulse would go from 35-75A giving you an 50A "effect". The lower the background the longer the puddle has to cool so, if the BG was at 60% everything stays hotter than if it were 30% (it put less heat into the metal during the "deeper" cycle). THEN the Time On also makes it MUCH Hotter/Colder too. The longer you're ON, the Hotter the weld so, a 50% Time On would be a Hotter "effect" than 30% but Colder than 60% (ie. with Main Amps @75 and change from 50% to only 30% background and you'd need to raise the Main to 100A, set 65% background and it might need only to be 60A). Mixed together (BG & ON) changes the Main Amps in Many ways with Many variables. I think you could find MANY combinations that would weld with the same "feel" at different settings...
The slow pulse (knob says (10) but I think it's really like 2) is OK for the outside corner but Impossible on the Inside or lap. It's too Hot and too Cold at the same time. Burns in a 'C" then won't flow the rod to fill it. Not sure that slow is right for much in thin Alum. Works better on the Outside corner but, I can get the 30pps to work too.
Fast(er) pulse 20-30ppm, when all else is set right, is Amazing in the inside corner & lap. Really makes a difference. The outside corner is always a challenge, more about proper angle, & correction of angle to compensate, than anything else...
The two Amperage controls (Background & Time On) RADICALLY change the Main Amps setting. Too little Background or too much Time On and the puddle stays HOT. You're really only "welding" during the Time On so the rest is recovering from the pulse and giving time to solidify. I'm not sure HOW but this is Very evident even at 30pps, you wouldn't think so but it is a big change.
So the "Pulse Amps" or "Ratio" are the background. That is, how deep the cycle is, how low the Amps go down to. It will go 95% but I'm not sure why??? If you were at 100A and set the BG to 95% then the pulse would go from 5A to 100A. I assume the arc would have to Stop when it got to 5A on a slow pulse if the tungsten wasn't really close. On a Fast pulse I'm not sure what it will do. I've been between 30-60% with noticeable differences.
And the "Time On" is when you're actually welding, adding filler to the puddle, so it has to be long enough for you to do that and not so long as to not allow the effect of the cooling or "freeze" you're after by pulsing in the first place. This means it has the most dramatic effect on overall Heat because it's how long the metal is exposed to the puddle.
SO ~ for the .22ga Alum Sheet I mostly left the MAIN Amps at 75 and was happiest overall at 50 BG & 40 ON, sometimes 50-50 was better and mostly 150Hz with 225Hz tacks. Tried everything from 30-30 to 40-60
Some surprises;
I was welding at 150Hz and tacking at 225Hz but if I welded at 225 the bead was actually wider. I would have thought the more "focused" 225 would have kept the beam more narrow.
Then there's the Pulse Knob which I can't make sense of the graduations. It's supposed to be .2-20 on low and 20-500 on High. But it doesn't feel that way. The .2 I count as being about every 1.5sec and dialed up 1/4 of the way (between 50-100 on the scale) looks to be about the 1PPS. Where it says (10) looks like maybe 2PPS.
When happy with the 75A and 50-40 (50% BG & 40% Time On) at the .2 (knob all-the-way Down on LOW) IF switched to HIGH (20PPS) it goes COLD and I Boost the Time ON to 50% and solve the coldest with just that change. 10% more TIME ON makes it that much hotter.
I would have also thought that the effect of the heat/cool pulse gives you would be negated by having to pulse Fast but at 30pps you can see the difference clearly and I think even faster will still do a lot.
This is, of course, all on Aluminum I don't know how well these Numbers are going to Transfer to Steel or SS.
Very informative blaster, thank you! It'll be tricky transferring your "knob" info to my "buttons" machine but it certainly helps. My weakness is aluminum, especially anodized...sheesh.
Blaster:
I'm glad I found this thread and will certainly make use of its valuable information. Your explanation makes a lot of sense now I just have to put in some practice time
Good info/place to start from.
Thank you for taking the time and effort to write all this information. Very useful, and I will continue to explore Pulse Settings based on the work you have started. Aluminum is my love / hate relationship, and I think the answer is in Pulse Settings until I get more experienced.