The ability to cut metal is what neatly and quickly can save you a ton of time in your welding operation and in your home shop. A plasma cutter provides the cleanest and safest cut when compared to oxy-fuel cutting, but plasma cutters have their disadvantages. Plasma cutters are both heavy and expensive.
If you’re going to invest in a machine with that kind of price tag, you’ll want to make sure you pick up the right one so that you have enough power to make the right cuts without cleaning out your bank account. Here are some things you need to look for in the right plasma cutter.
TIG/Plasma Combination Units
If you’re already planning on picking up a TIG welder for some finer work, you can pay a little extra for a TIG/plasma cutter combination unit. Some even add stick welding capabilities. This is a nice way to make your welding shop a little more versatile and to save money on both purchases and maintenance.
However, the one drawback is that any problems with one machine means you’re really missing both of them at the same time. If you buy a solid machine, this will hopefully not become an issue.
Plasma cutters can weigh anywhere from 60 to 100 lbs, which isn’t a big deal if you are rolling it around in a shop all day. If you want to haul a plasma cutter out of your truck, then a 20-22 lb portable unit will be ideal. The small unit will limit your cutting capabilities, but you’ll be prepared to take your plasma cutter wherever you need it.
Pilot Arc vs. High Frequency Plasma Cutters
Pilot arc plasma cutters are a more recent innovation in the field that is designed to reduce interference with electronics while cutting, provide a more stable cutting arc, and a longer consumable life since they don’t strike the metal when starting the arc. While pilot arc plasma cutters offer some cost savings in operation, they will tend to be more expensive when making a purchase.
Welding and fabrication shops have been using high frequency plasma cutters for years, and they certainly work just fine for the price. In addition, many electronics today are designed with shields from such high frequency currents that a plasma cutter may put off.
Cut Rating for a Plasma Cutter
What sets plasma cutters apart is how fast they can cut metals depending on a metal’s thickness: this is called the Cut Rating. This will help determine the price range of a particular plasma cutter. There are three classifications used in the industry according to Miller Electric:
- Rated Cut: The thickness of mild metal that an operator can manually cut at a rate of 10 inches per minute (IPM).
- Quality Cut: Rated at a slower speed but on thicker metal.
- Sever Cut: the maximum thickness a plasma cutter can handle. The travel speed is slower and the cut may require clean up.
Voltage for a Plasma Cutter
Plasma cutters come with three different voltage options: some units offer 115V and 230V power together (just switch the plugs in order to cut with more or less power), while there are units that only offer 115V or only 230V.
If you plan on running your plasma cutter off an engine, generator, or overseas where power is more prone to brown outs, consider purchasing a unit with voltage line compensation. This is a great feature to have no matter what, and it will save your plasma cutter from blowing out a circuit board or losing its steady arc while cutting.