Plasma Cutters are sort of like metal cutting wizardry the first time you use one. With recent improvements in technology plasma cutters the size of a lunch box can cut through incredibly thick pieces of metal. The plasma cutting process is pretty genius in how it works and we often get tech calls asking the science behind how they work so we decided to break it down a simple as possible for anyone wondering.
A plasma cutter needs two main elements to create its incredible cutting power. First you need an electrical arc that is passed through a torch lead. This can be from a transformer or an inverter power source. Inverter plasma cutters allow for a high frequency arc start or pilot arc that can jump start the plasma before jumping the gap from the torch tip to the work surface. It also means you don’t need to scratch the torch tip on the metal and it can initiate an arc through light rust and coatings found on metal. An inverter is much smaller and lighter weight than a transformer which translates into the entire plasma cutter package. All Eastwood Plasma Cutters are inverter based.
The electrical arc flows through tip of the torch and meets with a compressed gas being pushed through a constricted orfice(s) in the swirl ring . This compressed gas can be nitrogen, oxygen, argon, or the most commonly used; Compressed Air. When the high pressure gas mixes with the electrical arc it super heats the gas so that it turns into a plasma which is transferred to any electrically conductive work piece that is connected to the plasma cutter circuit by the ground clamp. This super heated gas or plasma jumps to the work piece and burns away or cuts the metal. The size of the cut will vary by the size of tip on the torch and also the distance or angle the torch is held at.
The ability to cut through thicker metal is determined first by the amperage the plasma cutter is set at. The higher the amps the hotter the cut that is made. The “punch” to force the plasma through the metal depends mostly on the pressure of the gas being fed into the torch. On Eastwood Plasma Cutters a maximum of around 60PSI is suggested to cut through metals up to 7/8″ thick with our Versa-Cut 60. Each plasma cutter may have different optimal settings so please check your owners manual.
The electrode tip and nozzle are the two “consumables” that will need to be replaced periodically. The frequency of replacement will vary by how extreme the job/cuts are, skill level, and temp rang you’re cutting at. Occasionally the swirl rings do need to be replaced, but very seldom if care is taken when replacing consumables.
Plasma cutters can run off of 110V or 220V depending on the model you use. Some inverter units like our Versa-Cut 40 have the ability to sense the input voltage and run off either with a wall outlet adapter. Obviously the maximum output is lower when running on 110V than 220V on dual voltage input machines.
So that’s a crash course on how a plasma cutter works and cuts metal so easily and efficiently. We suggest reading up on each machine and considering the maximum thickness you will need to cut before pulling the trigger on your plasma cutter purchase. Our full line of plasma cutting and welding machines can be found here: http://www.eastwood.com/welders.html .