TIG Frequency Question

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hi all... i've been lurking a bit and really enjoyed reading in on everyone's experiences/projects/advice/expertise. i have a lincoln squarewave 175. love the machine and it has been flawless from day 1i'm a hired-gun driver for a aa/fa team out of des moine, iowa. it's a really cool gig and i get to play with some really cool toys... and the boss pays the bills!! does it get any better than that? i have hand built my own cars in the past and my car owner is in the process of piecing together a new chassis for next season.ok... not to get too drawn out but we were at the PRI show in florida and he made a deal on a new miller TIG machine to upgrade from his syncro-180(?). my car owner and i were talking about our welders the other night when he asked me a question i had never considered. so i'll pose it to y'allhis machine has an adjustment for the hi-frequency level (not sure how it's measured). he asked me what the hi-frequency level was on my little lincoln squarewave 175 machine... and hell... i dunno?? there is no adjustment for it so is there a 'factory setting'? or does it vary with amperage? any input to help educate me would be greatly appreciated.ps... i did a search first for the word 'frequency' and went thru a few pages... but did not see any threads regarding this issuepss... keep up the cool posts/info/projects otherwise i'll have to get back to work
Reply:http://www.millerwelds.com/resources...rticles30.html"High-Frequency Intensity ControlThis control allows the operator to choose the proper intensityfor the high-frequency output. As this control is increased,the current in the high-frequency circuit is increased. Itshould be set for the required intensity to start the arc. It isrecommended that this control be kept at a minimum settingthat will provide satisfactory weld starts. The higher thesetting the greater the amount of radiation which will causeinterference with communication equipment."http://www.millerwelds.com/resources...Book_Chpt6.pdfEd Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:Inside your machine you will find a set of point contacts, factory set @ .015" gap. You can reduce the gap down to .008" to increase the frequency if you desire. I did just that and found my arc starts more reliably and at the same time it helped reduce arc wander. I use a Precisiopn TIG 375 that is also a square wave machine."SOUTHPAW" A wise person learns from another persons mistakes;A smart person learns from their own mistakes;But, a stupid person.............never learns.
Reply:Hello altered boy, I have a feeling there might be a slight mis-understanding of the interpretation of "frequency" here. Your mention of the "newer" Miller tig could bring me to believe that you might be considering "frequency adjustment", this would apply to AC current and control the switching capability of the output of the AC current, standard machines are based on 60 HZ(current switches 60 times a second from DC- to DC+), adjustable frequency machines are sometimes capable of a range from say 40 to 400 HZ. This can effect arc focus or depth of penetration when using AC current. If I am wrong about this and this was not your question please forgive me.      Referring strictly to high frequency intensity, some machines provide adjustability here to help limit the emittance of the high frequency as you only need enough to provide arc ignition, or, in the case of AC output, arc stability, the levels do somewhat change with different grades and diameters of tungstens as well. A bit more for you to consider. Best regards, Allanaevald
Reply:Originally Posted by aevaldHello altered boy, I have a feeling there might be a slight mis-understanding of the interpretation of "frequency" here. Your mention of the "newer" Miller tig could bring me to believe that you might be considering "frequency adjustment", this would apply to AC current and control the switching capability of the output of the AC current, standard machines are based on 60 HZ(current switches 60 times a second from DC- to DC+), adjustable frequency machines are sometimes capable of a range from say 40 to 400 HZ. This can effect arc focus or depth of penetration when using AC current. If I am wrong about this and this was not your question please forgive me.      Referring strictly to high frequency intensity, some machines provide adjustability here to help limit the emittance of the high frequency as you only need enough to provide arc ignition, or, in the case of AC output, arc stability, the levels do somewhat change with different grades and diameters of tungstens as well. A bit more for you to consider. Best regards, Allan
Reply:Basically, I hate aluminum. However, though I don't know what your machine can do, 200 hertz on AC for aluminum runs nice. And you can sure hear the difference.  It sure beats trying to stick welding aluminum, I can vouche for that.   Aluminum...City of L.A. Structural; Manual & Semi-Automatic;"Surely there is a mine for silver, and a place where gold is refined. Iron is taken from the earth, and copper is smelted from ore."Job 28:1,2Lincoln, Miller, Victor & ISV BibleDanny
Reply:Did you click on the First link?Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:Altered Boy, Those are some nice altereds, are both 125" WB. I built a couple of them myself but not for AA fuel. 1 B/EA 32 bantam CM and 1 E/A 23T bucket MS both used a 320CI chevy. Sold both, but still have the engine combo.Wish I still had some pictures. Darrell
Reply:Hello again altered boy, there is a distinction between "hi-frequency" and "adjustable frequency", they are completely different items that only share the word frequency between them. The hi-frequency is an arc starting aid, it allows the current to bridge the gap between the electrode and the work without physically touching and it is also an arc stabilizing mechanism when welding on AC, it carries the current through the zero point when changing from DC- to DC+ and back again. Adjustable frequency can be used to change the arc characteristics of the weld pool while using AC, Generally lower frequencies will allow for a wider and shallower penetrating weld pool, it can also aid with cleaning of heavy oxides or other surface impurities due to the increased forcefullness noticed from the slower change from DC- to DC+ and back again. An increased frequency rate can focus the energy of the arc in a narrower zone thereby increasing penetration and making the weld bead narrower as well. It may not be the best choice for dealing with dirtier surface and internal material situations as the oxide breaking characteristics exhibit lesser degrees of forcefullness.      I personally would opt for a machine with the frequency adjustability option because I believe it provides so much more flexibility regarding machine capability. That does come with a price tag though, so you have to be willing to ante up to get a machine that is equipped this way. I am familiar with the Miller Dynasty 200, 350, and 700, and the Thermal Arc GTSW 185 and 300 machines, all of them have the adjustable frequency ability and I believe any of them are a thoroughly capable machines. I am not familiar with the other offerings out there that could service this requirement so I can't speak to any of them, possibly others can. Considering what you are building these machines are likely not an absolute necessity, yet you would likely come to appreciate them almost immediately. The Miller 200/350 and either of the Thermal Arcs are very mobile thus making accessability to welding a breeze. So there's a bit of additional information for your consideration. By the way, the cars look awesome and I would bet they are a blast to "pilot". Keep up the good work and good luck on whatever you decide, machine wise. Best regards, Allanaevald
Reply:thanks for all the replies on the frequency issues... it definitely makes more sense to me now
Reply:Originally Posted by papabearInside your machine you will find a set of point contacts, factory set @ .015" gap. You can reduce the gap down to .008" to increase the frequency if you desire. I did just that and found my arc starts more reliably and at the same time it helped reduce arc wander. I use a Precisiopn TIG 375 that is also a square wave machine.
Reply:Originally Posted by lewrayThats something I didnt know.  Thanks for that one.  Im going to decrease the gap on my Syncro 250 and try it.Makes since to me..
Reply:Originally Posted by papabearIt only reduces the arc wander in AC mode, because that is when high frequency is constant. But it does make the DC starts more reliable, because in DC mode it's only HF for starting.