TIG electrode angel, and tip width question

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The machine is a Miller Diversion 165 Can someone tell me how the angle and tip width of the electrode affects the arc? I have a fixed nonadjustable tungsten grinder, it grinds the tip angel to 120*, the tip is a needlepoint, can be blunted is need be.Reading a welding book it suggest the angle for the tip of a 3/32 tungsten rod should be 45* and the tip width .045. What would be the differences of the arc between the angles and tip widths noted? Thanks In advanceMagazines have issues, everything else has problems
Reply:I grind the way your tungsten grinder does for DC. I use the same profile but with a slight blunt on the end for AC.I suppose the book recommends the profile it does for pure tungsten and AC work. For DC work that grind is supposed to emit a more focused arc, but I have tried it so many times and I need the needle profile for tight arc close up precision work that an inverter tig provides. But here are some examples, but I don't agree with the outcomes. I do some tiny welding and the top photos are unusable. Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Thank you that helps to give me a direction to go, I was concerned about the angle, will mess with the tip width.  Trying to keep the arc from wandering, the work piece is cleaned bright and acetone wiped. Arc acts like it has its own mind sometimes, trying to solve that. Took a week of vacation and thought it was a good way to spend it working on with the Tig welderMagazines have issues, everything else has problems
Reply:I prefer the 4th pic down, as far as tip prep goes. I prefer about 1/64" land on the end.As far as the arc wandering, that could happen if the grind lines of the tungsten tip are not parallel with the tungsten, but if you have a tungsten grinder, I'm assuming that the grind lines are going in the right direction.We have recently switched over from 2% thoriated (which I really prefer), to 1.5% lanthanated (which I don't like). Every now and then, we will get a "haunted" stick of it. These random pieces will not run right! The puddle will sometimes pulsate, the tungsten tip will develop a slightly rounded tip (even on DCEN), and a few other undesirable traits.Rich
Reply:I hand grind my tungsten on a dedicated bench grinder. I like mine as the 4th pic down showed also. DC tig welding only for me.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:I have a theory that electrons are led by those traveling on the surface of a conductor. Scratches made by even the finest grinder stones are like driving a car across the Himalayas. Electrons are hard pressed to jump from one mountain peak to another. The smaller scratches seen under a microscope on a polished tungsten are less an obstacle. I like the tungsten to remain cylinder shaped until it passes the cup of my torch. Low amp density on a tungsten causes arc wander. A long point on the tungsten seems to make the problem worse. A blunt grind, and a blunted tip will help keep your AC arc cone narrow.At higher amperage, a bull nose tip is preferred.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:Originally Posted by Willie BI have a theory that electrons are led by those traveling on the surface of a conductor. Scratches made by even the finest grinder stones are like driving a car across the Himalayas. Electrons are hard pressed to jump from one mountain peak to another. The smaller scratches seen under a microscope on a polished tungsten are less an obstacle. I like the tungsten to remain cylinder shaped until it passes the cup of my torch. Low amp density on a tungsten causes arc wander. A long point on the tungsten seems to make the problem worse. A blunt grind, and a blunted tip will help keep your AC arc cone narrow.At higher amperage, a bull nose tip is preferred.