Types of CNC Machines: CNC machines typically fall into one the two general categories: conventional machining technologies and novel machining technology:
Conventional Technologies:
Drills: Drills work by spinning a drill bit and moving the bit about and into contact with a stationary block of stock material.
Lathes: Lathes, very much the inverse of drills, spin the block of material against the drill bit (instead of spinning the drill bit and putting it into contact with the material). Lathes typically make contact with the material by laterally moving a cutting tool until it progressively touches the spinning material.
Milling Machines: milling machines are probably the most common CNC machine in use today. They involve the use of rotary cutting tools to remove material from the stock unit.
Novel Technologies:
Electrical and/or Chemical Machining: There are a number of novel technologies that use specialized techniques to cut material. Examples include Electron Beam Machining, Electrochemical machining, Electrical Discharge Machining (EDM), Photochemical machining, and Ultrasonic machining. Most of these technologies are highly specialized and are used in special cases for mass-production involving a particular type of material.
Other Cutting Mediums: There are a number of other novel technologies that use different mediums to cut material. Examples include laser cutting machines, oxy-fuel cutting machines, plasma cutting machines, and water-jet cutting technology.
Materials Used: Almost any material can be used in a CNC machine. It really depends on the application. Common materials include metals such as aluminum, brass, copper, steel, and titanium, as well as wood, foam, fiberglass, and plastics such as polypropylene.
