Plasma Cutting Tips Part 7

Setting up a plasma cutter is fairly straight forward, with connections, fittings, and wiring. There's not much to it for most people. However, plasma cutter settings to make a proper cut is another issue entirely. A lot of people have called me seeking advice on exact settings and hard and fast rules of plasma cutting. Unfortunately there are few unbendable rules related to plasma cutting. Any plasma cutter will make some sort of cut operated at maximum amps on the thinnest metal. However it may not offer the best cut. How to adjust your amps and air pressure to give the best possible cut properly is best learned through experience, following broad general rules. Each situation is different, due to mill scale, torch angle etc. But as a “general” rule setting the plasma up with the correct amount of amps is not that difficult. A good beginning point is to use 20 amps to cut up to 1/8” and for every 1/8” after that use at a minimum 10 additional amps. As far as air pressure, across brands, there is considerable variability. For Everlast, minimum cutting pressure is set at 35 psi. That doesn't mean it offers the best cut, only a “safe” cut. Typically lowering the airpressure from the maximum setting by 5-7 psi for every 10 amps reduction from maximum amperage is a good practice to offer the smoothest cuts. Again, this varies by manufacturer and is subject to vary. But it is a good place to start. The key is to watch the dross underneath the cut, and adjust it until it is reduced to a minimum. When all else fails use your eyes to tell the story. Keeping forward speed as stable as possible helps as well in dross reduction. Sudden bobbles and changes of direction will often deposit extra dross, so don’t be fooled.