How the CNC Plasma Cutter Works

The CNC plasma cutter is just one of the countless inventions that were developed due to the increased demand of factories during the Second World War. The breakthrough discovery was that inert gas could be combined with an electric arc in order to create a powerful welding tool. Since this time these machines have gone through many changes. It was discovered that because they could reach much higher temperatures than the typical welding tool, they could actually be used to cut through thick sheets of metal like a saw. This invention has improved the speed, accuracy, and the types of cuts that could be used in the manufacturing process.

The secret behind the CNC plasma cutter and its ability to cut through thick sheets of metal is due to the unique properties that plasma possesses. Most people are familiar with the three stages of matter, liquid, gas, and solid, but did you know there is a fourth stage, plasma? This stage is reached when the gas is heated to an even greater extent. This occurs when the energy actually begins to break apart and the molecules of gas and the atoms split as a result. The electrons separate from the nucleus and begin to move around furiously. The electrons will then collide with other electronics and ions which will create vast amounts of energy.

There are many different shapes and sizes of CNC plasma cutter table available which range from small, hand held tools to massive robot controlled machines capable of making the most precise incisions. However, no matter what size, they all operate in the same manner. Pressurized gas is sent through a small channel which contains a negatively charged electrode. A spark is then generated which heats the gas until it reaches the plasma state of matter which is so hot (30,000 degrees Fahrenheit) that it turns metal into a molten slag. As long as power is provided to the electrode and the plasma stays in contact with the metal being cut the arc will remain continuous.

A cutter nozzle is typically outfitted with several different channels which protects the cut from oxidation and regulates the plasma which can be very unpredictable. A constant stream of shielding gas is released around the cutting area from these channels which ultimately controls the radius that the beam travels on.

Although CNC plasma cutter machines were once only rarely used, today they are found in a wide variety of applications. Auto shops and manufacturers use them to easily create chassis and frames and construction companies use them for projects that require them to cut through huge sheets of metal.  They are now affordable enough that hobbyists can use them in their DIY projects. They can even be used by locksmiths to bore through massive safes and locks.