Introduction
A CNC (Computer Numerical Control) milling machine is a machine tool that uses a cutting tool to create physical components with a specified shape, size and surface finish. The work-piece is cut and machined precisely according to instructions sent to the machine from a computer numerically controlled (CNC) system. The machine is typically programmed using a special CAD/CAM (computer aided design/computer aided machining) software such as MasterCam.
The most commonly used CNC milling machines are based on the following parameters:
Travel Capacity: This parameter refers to the maximum distance between the cutting tool and the work-piece. The tool must be able to move a certain distance from one side of the work-piece to the other in order to cut a particular part.
Spindle Speed: The spindle speed is usually expressed in revolutions per minute (RPM). It is the rotational speed at which the cutting tool is fed into the work-piece. The higher the spindle speed, the faster the cutting action and the greater the efficiency of the CNC milling machine.
Feed Rate: This parameter is expressed in inches/minute and represents how fast the tool is fed into the work-piece in order to reduce material. The higher the feed rate, the quicker the cutting action and the greater the efficiency of the CNC milling machine.
Cutting Depth: This parameter indicates the amount and depth of material that is to be cut with each revolution of the tool. The cutting depth is usually measured in inches and depends on the work-piece and the material being cut.
Tool Selection: Some CNC milling machines are equipped with multiple cutting tools; others have only a single cutting tool.
Heel Relief: This parameter depends on the type of work being done and the tool being used. It determines how deep the cutting tool can cut into the work-piece. The heel relief is usually expressed in inches.
From the parameters described above, it is easy to see why CNC milling machines play such a crucial role in producing precision physical parts with consistent high standards of quality and accuracy. CNC milling machines are capable of producing extremely complex parts with exacting precision and repeatability, using a variety of cutting tools and speeds. This enables the production of large runs of identical parts or components in a relatively short period of time.
