April 2010 - There are a number of factors to consider when purchasing a plasma cutting tool. They include cut capacity, cut quality, reliability, duty cycle, ease of use and operating cost. The first step is to figure out what type of plasma cutting you plan to do. Are you planning to cut by hand or on a table? Some plasma cutting tools are capable of doing both, easily going from handheld to mechanized cutting and back again. A few systems include a CNC interface and internal voltage divider, which provides even greater options for mechanized applications.
Once you know what type of plasma cutting you are going to do, then you should consider the thickness of the material you plan to cut. The general rule is to choose a system with a recommended cut capacity that matches the material thickness you plan to cut 80 percent of the time. For example, if you mainly plan to cut 1/2-inch-thick metal, and only occasionally cut metal that's a little thicker (say 3/4 of an inch), then you can choose a 1/2-inch system.
Cut quality is another important consideration. Not only does it impact the quality of your finished piece, but it also saves time in later stages of production. Ideally, you want a clean, smooth edge so you don't spend a lot of time on secondary work. In addition to clean cuts, better plasma cutting systems create a much narrower kerf (cut width), which means more precise cuts and less wasted metal.
You should also consider reliability. The most reliable plasma cutting systems are engineered with fewer parts, use software instead of hardware when possible, are carefully manufactured to exacting ISO standards and are thoroughly tested. Ideally, you will want a centralized fan configuration to bring cool air in through the center of the system where the most thermally sensitive components are located. This will result in efficient and consistent cooling and enable a higher, more industrial duty cycle.
Simple operation is a requirement in a plasma cutting tool. Obviously, for an experienced operator, ease of use allows a job to be done faster and more efficiently, but it also means that people with little or no experience can get good results. Regardless of experience level, operators using plasma cutting tools can get jobs completed quickly and with good quality, keeping time-sensitive projects on schedule.
If you plan to move around or do any work away from your shop, then size and weight will play a role in your decision. Engineering advances mean you can now get a lightweight system without sacrificing power and performance. Certain plasma cutting systems also come with technology that automatically adjusts for different voltages and voltage variations, which is good if you plan to work off a generator.
Finally, you should consider operating cost. Cut quality, cut speed, and performance play a role here but so does plasma consumable cost. Plasma consumable life can vary significantly from one brand of plasma cutting system to another. Longer plasma consumable life is important as it reduces downtime for change-outs and lowers the cost you pay for new plasma consumables. The best brands use patented technology to extend plasma consumable life. MM