how to buy a used plasma cutter

That being said....on a daily basis I speak with users that have perfectly good running inverter (and non-inverter) plasma cutters that are 30 years old....and still cutting metal. The newer technology inverters (at least the ones from my company) are engineered and designed better....so I expect there will be an even higher percentage of them still performing well in another 30 or 40 years. Higher duty cycles, better cooling systems (keeping shop dust off the circuitry with clean side / dirty side cooling techniques), and higher rated components (IGBT's vs FET's) will prove to benefit reliability.

Torches on plasma cutters take the majority of abuse. They have to handle high temperature, high voltage, and the operator that uses them as a hammer. There are no "ceramic" parts in a Hypertherm Powermax1000 torch....but there are some high temperature composite insulators that certainly can crack or become damaged under hard misuse!

So...for the original poster in regards to purchasing a used plasma cutter.....I suggest sticking with the major brands. Look carefully at the condition of the power supply and torch, and feel free to call the manufacturers tech service department with the model number, serial number and they can look up the service history (if there is any) and can offer advice regarding the capability and serviceability (are parts available?).....and maybe even a strong opinion of the reliability of that particular model. I often give potential buyers my opinion of the price range of used, older models as well.

Jim Colt Hypertherm

Ziggy2 said:

The problem with the older inverter machines is the cost of replacing bad control boards. IGBTs are readily available but also are a bit pricey even from secondary sources.

The torch is also a trouble spot. We had a Hypertherm G1000 at work that was problematic for me to keep running. Good machine but at the time, Hypertherm had a slight design flaw in the torch design which has been fixed now with the new series of torches. The issue which took me forever to track down was that one particular user liked to use the torch to chip slag with as he was cutting with it. The slag hammer tapping action would crack a ceramic disk in the torch head preventing the arc to start or at least be sporadic.

The only reason why I bring up my story is that when you are buying a used plasma rig, unless you can test it at time of sale, I would assume that it is broke and price it accordingly. The used price plus the cost of one repair will probably exceed the price of a new rig.

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The older technology plasma cutters such as the Thermal Dynamics Pak5xr and the Hypertherm Max40 where both "transformer based". They also have circuit boards in them like inverter plasma cutters do. The circuit boards controlled output, timing, etc. Virtually anything with a circuit board will eventually become obsolete once the manufacturers of the discrete components on the circuit board stop manufacturing certain parts.....there are many integrated circuits (chips) that were widely used in plasma cutters, computers, industrial equipment, etc. over 20 years ago that have been superceded with newer, better designs. Electronics become obsolete over time......so it really doesn't matter if it is an inverter or transformer design....a plasma cutter or a welder...or a computer. Eventually it will have an issue that will cause it to be difficult if not impossible....to repair.That being said....on a daily basis I speak with users that have perfectly good running inverter (and non-inverter) plasma cutters that are 30 years old....and still cutting metal. The newer technology inverters (at least the ones from my company) are engineered and designed better....so I expect there will be an even higher percentage of them still performing well in another 30 or 40 years. Higher duty cycles, better cooling systems (keeping shop dust off the circuitry with clean side / dirty side cooling techniques), and higher rated components (IGBT's vs FET's) will prove to benefit reliability.Torches on plasma cutters take the majority of abuse. They have to handle high temperature, high voltage, and the operator that uses them as a hammer. There are no "ceramic" parts in a Hypertherm Powermax1000 torch....but there are some high temperature composite insulators that certainly can crack or become damaged under hard misuse!So...for the original poster in regards to purchasing a used plasma cutter.....I suggest sticking with the major brands. Look carefully at the condition of the power supply and torch, and feel free to call the manufacturers tech service department with the model number, serial number and they can look up the service history (if there is any) and can offer advice regarding the capability and serviceability (are parts available?).....and maybe even a strong opinion of the reliability of that particular model. I often give potential buyers my opinion of the price range of used, older models as well.Jim Colt Hypertherm