Figuring out Pulsed TIG

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I'm using a Miller SW 200 to do sheet metal 18-20G.  I am playing around with the pulse mode, but can't find anything but vaige references and staring points.  I've seen high pulses for thin material, and low pulse for thin stuff.  Other's refer to using the pulse to time filler.  I try to not use any filler on tight butt welds, but occasionally do.  Just wondering if there are any guidelines or starting points.  Also was trying to get a handle on the % at peak and % at background, I know it relates to travel speed, but it stops there.  It would be nice to not have to re-invent the wheel if one of you pros could offer a few tips.ThanksDavid
Reply:Cobra,As an example of pulsed TIG, here are settings for a 0.026" thick, 304 stainless steel tube, autogenous, butt weld, made by machine.travel speed = 6 ipmIpk = 40 ampIbk = 8 ampTpk = 53 msecTbk = 213 msecThis results in a full penetration weld, 0.080" wide overbead,  0.060" wide underbead, with 70% pulse overlap.Doing some math, you can convert these settings to different units, depending on how your machine is set up.Ipk = 40 amp%Ibk = 8/40 = 20% of IpkPulse frequency = 1/(.053+.213) = 3.8 ppsPeak duty cycle = .053/(.053+.213) = 20%Iavg = (.2x40)+(.8x8) = 14.4 ampsI like to use a very short duration, high amplitude, peak pulse to produce the full penetration spot weld.  This is followed by a very low amplitude, long duration background pulse, during which the arc is maintained but is not doing any melting, and the torch has moved forward the correct distance for the next peak pulse to overlap the previous one by at least 70%.This web site has pulse calculations you can experiment with.http://www.pro-fusiononline.com/welding/pulserate.asphttp://www.pro-fusiononline.com/welding/pulseparams.asp
Reply:Thanks that's the most concise data I've seen in one spot.  The web calculations are also very cool.  Most of the books and info that I have just seem to brush over pulse mode,  without any in-depth explanations.  I'M out to the shop to fire it upThanks AgainDavid