What to look for in a plasma cutting machine: Part 2December 2, 2014 REDWIRE is news you can use from leading suppliers. Powered by FRASERS.
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You’re in the market for a plasma cutting machine, but you don’t know where to start. You’re not alone.
Lincoln Electric has compiled this list of factors to consider when making a buying decision. Part 1 can be found here.
Pilot to cut and cut to pilot transfers
The transfer from pilot arc to cutting arc occurs when the pilot arc is brought close to the workpiece. A voltage potential from nozzle to work is the mechanism for this transfer. Traditionally, a large resistor in the pilot arc current path created this voltage potential. This voltage potential directly affects the height at which the arc can transfer. After the pilot arc transfers to work, a switch (relay or transistor) is used to open the current path. Look for a machine that provides a quick, positive transfer from pilot to cutting at a large transfer height. These machines will be more forgiving to the operator and will better support gouging. A good way to test transfer characteristics is by cutting expanded metal or gratings. In these instances, the machine will be required to quickly transfer from pilot to cut and back to pilot very quickly.
Check the machine's working visibility
You want to be able to see what you’re cutting, especially when tracing a pattern. Visibility is facilitated by the geometry of the torch — a smaller, less bulky torch will enable you to better see where you are cutting, as will an extended nozzle.
Look for portability
Many consumers use their plasma cutter for a variety of cutting applications and need to move the machine around a plant, job site or even from site to site. Having a lightweight, portable unit and a means of transportation for that unit makes all the difference.
Determine the ruggedness of the machine
For today's hard job site environments, look for a machine that offers durability and has protected controls. For example, fittings and torch connections that are protected will wear better than those that aren't. Some machines offer a protective cage around the air filter and other integral parts of the machine. These filters are an important feature since they ensure oil is removed from the compressed air. Oil can cause arcing and reduce cutting performance. Protection of these filters is important as they ensure oil and water, which reduces cutting performance, is removed from the compressed air.
Find out if the machine is easy to operate and feels comfortable
Look for a plasma cutter that has a big, easy-to-read control panel that is user-friendly. Such a panel allows someone who does not normally use a plasma cutter to be able to pick it up and use it. In addition, a machine with procedural information clearly printed on the unit will help with setup and troubleshooting. Pay attention to how the torch feels in your hand. You want something that has good ergonomics and feels comfortable.
Look for safety features
Look for a machine that offers a true Nozzle-in-Place safety sensor. With such a feature, the plasma cutter won’t start an arc unless the nozzle is in place. Look for a machine that provides a three-second pre-flow safety, which gives users advanced warning to make sure all body parts are clear of the nozzle before the arc initiates.
Now you know what to consider when buying a plasma cutting machine. For more information, contact Lincoln Electric.