Plasma settings and consumable life?

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To maximize consumable life, should you run max amperage and cut fast or lower amperage and cut slower?Ian TannerKawasaki KX450 and many other fine tools
Reply:Make sure the air is DRY.  damp air will kill your consumables in short order...   Avoid blowback and use correct standoff or proper drag tip.    Your amperage is more for the cut quality.   its hard to keep up with the cut if you run hi amps on sheet metal etc..  I cannot say I have noticed much difference in consumable life purely from the amperage setting of the machine.   Otherwise it is just brand/machine dependent on how long the tip lasts.    I have been abusing the heck out of the tip on the Forcecut 42i and have yet to kill the first one.  would have killed a couple of nozzles on my ESAB doing the same I did with the Forcecut..    Ask Lanse how the consumable life is on his Forcecut compared to his Hypertherm 45..Tiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:With a Hypertherm torch the best consumable life is with the book spec amperage (ie. 45 amps for a 45 amp set of consumables, 65 amps for a 65 amp set), the book spec air inlet and torch pressure settings, as well as the proper pierce height, cut height and speed.Reducing the amperage on a set of consumables is sometimes detrimental to life as it allows blowback on the nozzle. Low air pressure will cause nozzle wear, high air pressure will cause electrode wear.Cutting to slow increases the nozzle heat load, cutting too high off the plate can do the same.There is a balancing act of cooling, insulating values and conductive properties inside every plasma torch....this is to create a 25,000 plus degree arc out of ordinary compressed air. When you change the balance....expect an affect on consumable life!Jim Colt  Hypertherm Originally Posted by fortyonethirtyTo maximize consumable life, should you run max amperage and cut fast or lower amperage and cut slower?
Reply:What exactly happens to the consumables in a plasma torch? I've had a plasma cutter now for the last month. I haven't cut a huge amount but I've been using it and I haven't noticed any change in the tip. I did have to clean off some, what I guess was blow back, but that's about it.
Reply:A shielded plasma torch (like all Hypertherm units above 30 amps output) have an electrode, a nozzle and a shield (no part called a tip). Most other manufacturers torches are unshielded, and have an electrode and a nozzle (some call the nozzle a tip).The two parts that wear most rapidly are the electrode and the nozzle. The electrode is the negative side of the plasma arc, the material being cut is the positive side. The torch nozzle is at positive potential at the begining of each cut in order to get the pilot arc started (an arc between the electrode and the nozzle that is forced through the nozzle orifice by air pressure), then, if the torch is within striking distance of the plate the arc transfers from the nozzle to the plate....at this point the nozzle is electrically "floating", and the function of the nozzle is to create the cylindrical shape for the arc, as well as to increase the velocity of the arc.The plasma arc in an air plasma torch has a temperature in excess of 25,000 degrees F. The nozzle, made of copper (for excellent heat transfer) which melts at less than 1100 degrees F.....uses some advanced technology that internally swirls the air flow....which slings cooler molecules to the surface of the nozzle bore, which insulates the nozzle from the high temperature arc...allowing the nozzle to remain solid.  The electrode has an insert made of Hafnium (an earth element)....hafnium is a great emitter of electrons and holds up well in an oxygen rich environment (air is 20% oxygen).....so it becomes the arc attachment point.Needless to say....under the high temperature conditions inside a plasma torch...the electrode hafnium emmitter eventually evaporates, ultimately the cut quality will change and the torch will start misfiring. The nozzle bore also erodes....changing the shape and energy density of the arc, also affecting cut quality. Shielded torches have a shield that electrically isolates the nozzle from touching the plate.....and more advanced shield designs dramatically improve nozzle life and cut quality through increasing the energy density of the arc and super cooling of the nozzle exit bore.So.....when the nozzle orifice becomes eroded and out of round, cut speeds will slow down and cut edge angularity will suffer. You will get more dross, and eventually the torch will not cut at all. When the electrode hafnium wears to a certain depth (differently affected on different torch designs) it will also affect cut quality and will eventually stop working.With a hand torch...often you can run consumables until near failure....as your hand can tip and change speeds to accomodate the changes in cut quality associated with consumable wear. On a mechanized torch....consumables often get changed sooner...as cut quality is often more closely monitored on cnc cutting applications.Better quality torches that are well engineered will produce better cut quality as well as dramatically longer consumable parts life....making for a more precise cutting process with a much lower cost of operation.Hopes this helps understand consumable parts wear in a plasma torch.Jim Colt  Hypertherm Originally Posted by herbet99What exactly happens to the consumables in a plasma torch? I've had a plasma cutter now for the last month. I haven't cut a huge amount but I've been using it and I haven't noticed any change in the tip. I did have to clean off some, what I guess was blow back, but that's about it.
Reply:Originally Posted by jimcoltHopes this helps understand consumable parts wear in a plasma torch.
Reply:If you have a Hypertherm....simply open your manual up to the consumable inspection section...and it explains how to inspect the consumables. The electrode develops a "pit" in the center hafnium emitter. Once the pit gets to a cetain depth...then the electrode should be changed. The depth will be different with different torch designs....so what works with a Hypertherm Duramax torch will be different than with other torches.Jim Originally Posted by herbet99Yes, it does. Thanks. Is the wear of the electrode something you can visually inspect or is the degradation of the cutting results the only way to know that your consumables are.. well... consumed.
Reply:Thanks again.