Working on a sign, 12” letters, and at random the cutter has been losing the arc when it seems to be cutting fine just before. Mach3 is still showing as if the torch is firing, but the plasma cutter light is no longer lit. (Harbor freight cutter by the way). I’ve been able to salvage some pieces by just re-firing the torch from Mach3 when the program gets to a certain point and it seems to cut along just fine.
Any ideas why this is going on?
I’ve tried replacing the tips a couple times as well
Are you using a descant filter or anything to clean and dry the air? I know mine would do that from the water table being too high causing it to splash into the torch and cause a no fire(extinguished) arc as well.
I have a home made air dryer with 3/4” copper tube and a filter desiccant dryer from harbor freight after it before it goes o the machine, I did just add water to the table, I’ll try lowering the water level
It is fairly common to experience “arc blowout” with some plasma cutters. This occurs in very sharp angles (common with many fonts) where the torch kind of backtracks over an already cut kerf, this makes the arc voltage increase, exceeding the capability of some plasma power supplies…so the power supply senses this as though you cut off the edge of the material and it will shut off. Others things that cause loss of the arc are 1. Cutting too slow on thin materials. 2. Low input line voltage to the plasma power supply, 3. Cut air pressure set too high. 4. Cutting too close to the edge of the material. 5. worn electrode and / or nozzle (they are called consumables because they wear out). Jim Colt
As Jim said, I think you need more cut speed.