No Pulse?

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Its dead, Jim!  Ok, so at my new job, we are using two ancient Hobart Arc Master 351 machines.  They have pulse settings in the controls on the power source which are selected and as far as I can tell, should be yielding a pulsed spray mig weld.  Unless it is stealth pulsed, it is not pulsing.  I can't seem to convince anybody of this as I am the only "trained" welder in the shop.  The general thought is that since the settings say that the machines are pulsing, then they must be pulsing Does anyone have any experience with these machines?The other problem is that we have a Miller Maxtron 450 powersource with a 75 series wirefeeder.  We cannot get the machine to run even a short circuit bead.  I have checked polarity, settings, everything I can think of.  All that happens is that the wire just forms large balls and just rolls off the base metal.  No penetration.  My theory is that the problem is one of the settings on the powersource or that the powersource is not communicating with the wirefeeder.Any Ideas?
Reply:I never used any of those machines, but pulsed spray should sound like a bunch O Bumble bees.It might be a dumb question, but for the miller maxtron, do they have the right gas?  Could be the voltage is stuck too high.  As in not responding to adjustment.  Will it sort of spray if you crank the wire speed up?DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:I don't have any experience with that Hobart machine but I've done enough mig pulsing.  This may sound rediculusly obvious, but if you turn off the pulser and weld and it doesn't weld any different than with the pulser on, then either it's not pulsing, or the pulse controls are set such that the pulse is practicaly defeated.  The puddle is usually cooler with the pulse than without.  I don't know what the pulsing controls on that machine are, as most control the pulse in different ways, but if you increase the pulse on-time (or pulse width), peak pulse level, or frequency, the puddle should get hotter, and vice-versa.I've never heard of 'stealth pulse'.  Sounds like you work with some idiots, good luck convincing them of anything...On the Maxtron, is there any arc at all, or is it just very weak?MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Here's the link to the owner's manual for the Maxtron 450 if it helps any...http://www.millerwelds.com/om/o2206g_mil.pdfMM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:I have a couple old Airco PA-3A pulse machines that do not have the swarm of bees sound when they are pulsing. I am sure the big cooling fan drowns out some of the sound but when they are set right on they are great. The settings can be a little finicky untill you have spent some time getting used to the machine. On the Aircos once the sweet spot is found onthe voltage side I leave it alone and adjust from there with the background.
Reply:Try to do an overhead weld in spray mode.  If you can do it, there is pulse somewhere.And as mentioned, turn pulse off and do a weld.  Turn pulse back on and do another weld.  If there is no difference, then something is wrong.Oh, and did you check the manual?    The best laid schemes ... Gang oft agley ...
Reply:I have done overhead welds in spray mode with the Hobart machines while set in pulse.  The reason that I don't think that they are pulsing is that the beads don't have the stack of dimes look and there is no noticeable voltage drop.  I have had my supervisor watch the voltage readout on the machine and it doesn't drop voltage like I believe it should when pulsing.As far as the Maxtron, we have a pendant on order so we can do pulsed welding with it.  I have tried fooling around with just about every setting on the powersource with no luck.  If I turn the voltage down, then end of the wire sticks to the workpiece and just makes a weird sound.  With the voltage slightly higher, the wire just forms weird molten globs with no penetration.  I have the manuals for all the machines and wire feeders, but haven't had any luck with them.
Reply:Stack o' dimes look doesn't really mean there is or isn't pulse going on.If the pulse speed/duration/peak-amperage/background-amperage/etc are set certain ways, you'll pretty much just get what you think is smooth spray transfer.Except you could do an out-of-position spray with it.  And the response time on the meters might not be fast enough to show the pulsing.  So don't really rely on the machine's meters there.If you hook something like David R's diagnostic scope/meter to it (the one he used when he was wringing out the 120V MIG unit, etc), then you probably could see/capture the pulse information.Turn the pulse off and do an overhead spray weld.  If it drops on your head, then the pulse was off.    The best laid schemes ... Gang oft agley ...
Reply:None of the pulse units I have welded with (Miller, MK and PowCon) have created any 'stack of dimes' bead look while moving the torch straight and even.   The beads have always been smooth spray beads, nothing more.The pulse happens way too fast (several times per second, 60Hz or greater) and will never be seen on either a digital or analog meter typically found on a welding machine.  When the pulse is working, you will see the tiny stream of metal shooting off the end of the wire, with very little to no spatter, when set up right.  On my Miller, the sound is like slowly ripping saran wrap of a roll.   On my PowCon, it's a screaching EEEEE sound.   The MK's were fairly quiet.If your Maxtron and feeder are not working together now, I doubt buying a pulsing pendant for it is going to magically make them start working.   You have to solve whatever issue exists now before adding a pulser to the complication.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:On carbon steel, I don't get a stack O dimes in pulse unless I wiggle the torch to get them.  Just a nice smoooth bead.  ONLY on aluminum with my machine set on "Pulse on Pulse" do I get the stack O dimes and its supposed to do that.  I just use regular pulse on aluminum anyhow.  I don't need no stinkin dimes.In pulse spray mig on carbon steel, the puddle looks more like tig and controls more like mig.Welds great out of position once I get the heat right.Good luckDavid Real world weldin.  When I grow up I want to be a tig weldor.