Tips for Buying a Plasma Cutter
Are you thinking of buying a plasma cutter? It can be difficult to purchase a type of equipment you’re not familiar with, especially that there are several models and manufacturers to consider.
To begin with, there are a few questions you should answer before going shopping:
> How often in a day do you plan to use the equipment? What duty cycle should it have in other words?
> What electrical service type is available in the area where you will be using the machine? Will it be 30 amp 110 volt single phase or 50 amp 220 volt single phase perhaps? What other machines or tools will be run on the same circuit simultaneously?
> What level of portability should your plasma cutter have? Are you going to use it in your shop exclusively, or do you have to take it to the job? Do you have way of supplying compressed air to the machine when you take it to a remote location? Will you be using an air bottle or portable compressor? How can you provide electric current onsite?
> What kind of material would you like to cut and how thick might it be?
> Manual cutting or with a CNC cutting machine? Usually, a higher amperage output would mean a greater duty cycle at a lower amperage. Many people believe that a greater-capacity machine is always better, but this is false. Fabricators usually consider oxy-fuel as superior to plasma for cutting steel that have a thickness of .5 inch or more; this is because of the 4 to 6-degree bevel in the cut face made by the plasma. It is not obvious in thinner materials, but it becomes more noticeable as thickness increases. 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 you intend to cut non-ferrous metals like stainless or aluminum, which could not be cut by oxy-fuel, think 50 to 80 amp 220 volt plasma cutter. If you’re going to use your plasma cutter outside the shop sometimes, you have to consider getting one of new breed of semi-portable types. These units are small powerhouses weighing under 100 lbs., but they can cut .75″ to 1″ in a pinch. You’re going to need a bottle of air or a compressor, as well as a portable generator.
If you automating your plasma cutting is a possibility, then get a unit that which doesn’t use a high-frequency starting circuit. A high-frequency start operates like the spark plug in your vehicle. Rather than relying on lower voltage pilot arc to begin the plasma process, it counts on a high voltage spark, which produces electrical interference like computer lockup or destroying files, etc.
Source: Plasma Cutter