Buy a Used Plasma Cutter and Save

Plasma cutters don’t have much in the way of moving parts so a used plasma cutter either works or it doesn’t. The main part is the power source. If the used plasma cutter develops an arc then the power source is probably working. Quality of cut is controlled by the condition of plasma cutter consumables and the quality of the air supply. If the used plasma cutter you are looking at works and cuts then that is the most important test. Used plasma cutters that operate properly and are in good condition can save some you some money.

Power Source – A used plasma cutter consists of the power source, electronic starter circuit, thermal protection circuit, and fan control circuit. The only moving parts are a cooling fan, a gas solenoid, and the torch assembly trigger. The electrical motors and switches and the electronics are probably ok if the unit cuts the thickness of metal for which the plasma cutting machine is designed. The power source of used plasma cutters pretty much either work or they don’t. Here is an opportunity to save money on a used plasma cutter.

Starter Circuit – If the electronic starter circuit of the used plasma cutter works ok then the arc will start easily and hold steady during the cut. An unsteady arc can also be caused by dirty air. Air contaminated with oil or water will cause intermittent arc and reduce cut quality of used plasma cutters.

Gas solenoid – When the torch trigger on the used plasma cutter is pulled, the gas solenoid will turn on. If the gas solenoid isn’t working then there will be no air flow and thus no plasma stream. After the cut is finished and the trigger is released the solenoid stays on for a few seconds to provide post cut air flow to cool the torch assembly. A good quality name brand used plasma cutter will have this post cut air flow feature.

Fan Control – Depending on the age and manufacturer of the used plasma cutter, the cooling fan will either run continuously at power on or cycle on and off during operation. On newer plasma cutters the fan may not run unless the plasma arc is established. and then it cycles on and off to cool the power source as needed. My Hypertherm 1000 plasma cutter is like that. It only cools when it needs to.

Torch Assembly – On a used plasma cutter the only moving part in the torch is the trigger switch. This should operate smoothly with no binding. The tip and nozzle are easily replaced. They are consumable which means that they wear and are used up whenever the plasma arc is flowing through the nozzle tip. The condition of the plasma cutter consumable nozzle and electrode has a great effect on cut quality of used plasma cutters. The hose is replaceable, inspect for cuts and abrasion. Hose condition should be considered when pricing a used plasma cutter.

Ground Clamp – The ground clamp on used plasma cutters is often overlooked. The plasma cutter depends on current flow through a complete electrical circuit. The ground clamp returns current flow back to the power source. The ground clamp on any used plasma cutter should not get hot during operation. Heat at the ground clamp indicates a poor, high resistance electrical connection. Replacing a worn and broken ground clamp can greatly improve the operation of a used plasma cutter.

Plasma Cutter Consumables – The nozzle and electrode wear as the plasma arc flows through the constricting orifice. The orifice is designed to constrict the plasma which concentrates the heat, increases the temperature, and increases the velocity of the plasma stream. As the orifice and electrode wear the stream velocity decreases and the temperature decreases which causes a longer preheat time and noticeably affects cut quality. Always keep a supply of consumables on hand. A properly working used plasma cutter can be a good buy and may work as well as a new unit by just replacing the torch nozzle and electrode.

Appearance can tell you something about the care and use of a used plasma cutter. If it looks well cared then it probably was. If it is banged up and dirty then these are signs of neglect or abuse. The appearance should be considered before the purchase when pricing used plasma cutters.

There are other considerations when buying used plasma cutters. If the unit is too old then it could be missing some nice to have technology. Modern starting circuits make a big difference in establishing and maintaining a steady arc, and there are other factors such as current regulation, thermal protection, and cooling technology that should also be considered. take all these into consideration when buying a used plasma cutter. And by all means stay with the major brands of used plasma cutters