Tips for Buying a Plasma Cutter
Do you plan to buy a plasma cutter? Its can be overwhelming to purchase equipment that is new to you, not to mention there are so many models and manufacturers and models to select from.
As a start, there are a few questions you should ask yourself:
> How hours of daily use will the equipment get? In short, what duty cycle should it have?
> What electrical service type is available in the area where you will be using the machine? Is it 50 amp 220 volt single phase, or maybe 30 amp 110 volt single phase? What other machines or tools will be run on the same circuit simultaneously?
> How portable do you need the equipment to be? Will you take it outside or will you use it strictly in your shop? Will you be able to supply the machine with compressed air in a remote location? Will you be using an air bottle or portable compressor? How about supplying the supply electric current at the site?
> What type of material do you intend to cut, and how thick will it probably be?
> Will you only do manual cutting exclusively, or will you probably use your plasma cutter with a CNC cutting machine? Typically, higher the plasma cutter amperage output come with a greater duty cycle at lesser amperages. Plenty of people think that a machine with greater capacity is always better, but not necessarily. Fabricators generally consider oxy-fuel to be better than plasma for steel cutting steel with a thickness above .5 inch; this is due to the slight (4 to 6-degree) bevel in the cut face produced by the plasma. You wouldn’t see it in thinner materials, but it does become more noticeable with increased thickness. As well, at above .5-inch thickness, plasma has no advantage over oxy-fuel in terms of speed.
If you’ll be using acetylene for the work, there will be nearly no point in purchasing a plasma cutter. If your intention is to cut aluminum, stainless or any other non-ferrous metal, which oxy-fuel cannot cut, get a 50 to 80 amp 220 volt plasma cutter. If you must take your plasma cutter outside the shop, get one of those latest semi-portable machines. These are little powerhouses weighing below 100 lbs., but they have the ability to cut .75″ to 1″ in a snap. You’re going to need a bottle of air or a compressor, as well as a portable generator.
If you think you might automate your plasma cutting in the future, pick a unit that that runs on a low-frequency starting circuit. A high-frequency start operates like the spark plug in your vehicle. Instead of using a relatively lower voltage pilot arc to start the plasma process, it relies on a high voltage spark, which causes electrical interference like destroying files, locking up the computer, and so on.
Source: Plasma Cutter