How to Use a Plasma Cutter?

Answer 1

A plasma cutter is a device that uses compressed air or an inert gas blown through a high speed nozzle to cut metal. As the inert gas or compressed air is blown out of the nozzle, an electric arc is formed from the nozzle to the surface of the material being cut. Some of the inert gas or compressed air is converted into plasma as it touches the material being cut, and the heat from this plasma is used to cut the metal. There are two types of plasma cutters most commonly used in commercial applications. The HF (high frequency) Contact plasma cutter initiates an arc by using a high frequency, high-voltage spark to ionise the air through the torch head. While the use of this method is quite common, it is not suitable for CNC cutting applications because it requires the torch to be in contact with the material that is being cut. The other method commonly used in commerical applications is the Pilot Arc method. This method uses a high-voltage, low current circuit to create a spark within the torch body. The creation of this spark generates a pocket of plasma gas, or a pilot arc. The pilot arc is able to maintain itself because there is a return electrical path in the torch head. The pilot arc is maintained until the torch comes into contact with the material being cut, at which time the main plasma cutting arc is ignited. Because this method does not require the torch to be in contact with the material it is cutting in order to ignite, this type of plasma cutter is used across all plasma cutter applications. Over the last decade, manufacturers of plasma cutters have continued to roll out new models that feature smaller nozzles and thinner plasma arcs. As these components have become smaller, plasma cutters have been reduced in size to the point where there are now hand-held plasma cutters. This development has made plasma cutters not only easier to handle, but also much more precise. Another benefit of the increasing miniaturization of plasma cutters has been a reduction in their cost. This reduction in cost has now made the purchase of a plasma cutter within the reach of most hobbyists.