CNC Cutting Methods
When required to do Computer Numerically Controlled (CNC) metal cutting services, there are three different methods - Plasma Cutting, Waterjet Cutting and Laser Cutting. To decide which of these methods is best suited for the work on hand, one should know the three different application areas.
If cutting involves a piece of metal below one inch thickness and requiring moderate to strict tolerances, laser cutting should be the preferred choice. If a metal is made of any unusual material with low tolerance to heat, then waterjet cutting method is the one to opt for. If the material is metallic and extremely thick beyond 1.5 inches and speed is criticial, then plasma cutting would be ideal.
Plasma Cutting involves high temperature plasma and an electric arc seeking ground as this process is designed to remove metal by melting the material and blowing it away from the work area. Plasma cutting has by far the fastest speeds when cutting thick metal. Plasma cutting requires electricity and certain gasses to function. The plasma cutting process uses a controlled electrical arc to create a superheated gas plasma jet. This electrically conductive, ionized gas plasma is hot enough to easily cut through a variety of metals.
In recent years there has been rapid advancements in the CNC Plasma Cutting Machinery. Traditionally the machines' cutting tables was horizontal but now Vertical CNC Plasma Cutting Machines are available. For thinner material cutting, plasma cutting is being replaced by laser cutting primarily because of the laser cutter's superior hole-cutting abilities.
Waterjet cutting involves abrasives and high pressure water resulting in precise abrasion cutting. Steel parts can be as thick as 6 inches and materials can range from metal to ceramic tiles and other material in between. It is indeed the slowest method of the three types of cutting services. Apart from the supply of water, the waterjet method involves expensive tiny rocks called garnet. Water jet cutters are able to cut soft materials such as rubber gaskets at very fast rates, and with a quick change in cutting heads, thicker materials such as 4" stainless steel can also be cut instantly. The waterjet cutting process uses a low volume, very thin stream of ultra high pressure water for cutting high precision parts.
Laser cutting involves light moving in a straight line and in the process, removes metal by vaporization. Laser cutters usually have rigid tolerances and are capable of precise cutting. They are also the fastest at cutting thin material and some more powerful laser cutters can cut mild steel as thick as 1.25 inches. The supply of the laser involves laser gasses and electricity. The laser cutting process uses a focused beam of high energy infrared laser light to cut material by selectively vaporizing and melting a highly localized area, while an assist gas is used to remove the molten material from the resulting cut.
When you search on-line many advanced CNC techniques are available. that are not commonly presented in a regular CNC tutorial. Benefits of applying advanced techniques include minimizing setup time, reducing cycle time, shortening programs, making machines easier to run and generally improving the company's CNC programs.