[skinart]

Hey guys, I have recently bought a cheap multi function machine which has a plasma cutter as one of the process's anyway ..

while I put a new tip, and electrode piece in the torch, it cuts great ...... but only after a very short time the tip starts to melt and the electrode inside starts to melt and pit also .... I have tried increasing and decreasing voltage but it still seems to do it, I have tried running the torch just above the surface and also dragging it along the metal .... not sure which is the right way but both still seem to end in the same result.

When it has the new parts in it the arc is nice and straight and strong and cuts awesome, but I can tell when it starts to melt as the arc starts to wonder and I can hear it start to spit and splatter ugh!

Do you guys have any tips for me that may stop this from happening? Im guessing it must be something im doing wrong as when I first start it works a treat, but in under 1 minute it will start to destroy the tips ..

Hey also, when I hold the torch in the air and squeeze the button only air flows ... it doesn't throw an arc? Im sure the miller I use to use would arc while in the air even without having to get close to the metal ... is this normal?

Im running 65 psi through the reg, and I turn the amperage up until it penetrates the metal I am cutting. Which is around 35 amps at the moment.

*edit*

I just tried it on some thin steel with an amperage of 20 amps, and it doesn't melt teh tip of the electrode, it seems to work just fine .... so its only when using 35+ amps ... so im guessing its just from to much heat? I have no idea how the torch is meant to disperse its heat but Im guessing its unable to.

[rickbreezy]

First off, i dont know much about plasma cutters.

but my 2 cents worth would be that maybe your holding the tip too close to the metal. I ussually use a 3/16-1/4 gap to cut steel. Also, are you using a gas cup, becuase I know that not everyone does and it seems that a gas cup greatly improves the life of your consumables.

Oh, and the plasma cutter I use also throws a "plasma" or "arc' thing while I press the button mid-air also.

But the best advice I could probably give you is to read the manual for the amp. specifications.

hope it all works out,

-Rick

[tjsmetalart]

keep your machine voltages below tip voltage 20 amps on machine for 20 amp tip 40amp at machine for 40 amp tip and check for water in your air install a good air dryer check the tip # and see if its a drag tip,they can ride on material while cutting with out problems if its not a drag tip keep off the material about 1/16 while cutting

[jakeru]

I experienced high rate of tip erosion on my multifunction plasma cutter (a "Super200P"... without pilot arc) until I made the following changes:

1. I installed an inexpensive (< $10) inline dessicant air dryer in the air supply, right at the unit's air inlet (see picture.)
2. I switched from an arc welding helmet (with a too dark for plasma cutting Shade 9) to a much lighter (oxy acetylene appropriate, shade 5) eye protection, so I can actually see the torch and surface when cutting and keep it held the proper ditance and *not* bump the torch into the work surface!
3. I got the high frequency gap setting inside the machine dialed in (and cleaned the contacts to fresh, shiny metal) so I can start reliably (on bare metal surface) without touching the torch on the work surface. In a nutshell, more spark gap = more voltage can be built up in the HF arc, which can make it bridge a longer gap, however too much gap can damage your equipment. (For more on spark gap, see this thread post I made on another forum: http://weldingweb.com/showthread.php?t=35536 )
4. Avoided inside corners! Those are hard to do without touching the torch on the surfaces. You will ruin your expensive tips...

Also, it helps if you do touch the tip, to stop plasmaing, let things cool off inside, and inspect them. Keep the copper parts especially where the arc occurs inside shiny and fresh copper. (Clean off dirty/dark looking copper oxidation as needed with a file or wire brush.)

[anthonyfawley]

Dryer is a must. keep a 3/16" to 1/4" gap from tip to steel (you can see the slag build up, just be higher than that), also change the tip and electrode together, try not to use an old electrode and a new tip ( gets costly i know). It helps when cutting thicker steel 3/16" or larger to drill a small hole 1st so the blowback dont kill the tips, or at least hold it on a bit of an angle. aluminum 1/8" or smaller you could almost drag the tip and still be fine, it actually makes it easier when cutting straight lines draging the side of the torch along a straight edge with the tip dragging on the thin aluminum. be sure to check recomended air pressur as well. I have a miller and have about 80-90 psi, it cuts 1-1/4" steel pretty good but its a slow process. good luck.

Anthony