There are many types of equipment for precision machining, such as CNC milling machines, CNC machining centers, CNC drilling machines, CNC grinders, and CNC lathes. Below is a brief introduction to CNC milling machines, which vary in size, axis configuration, feed rate, cutting speed, milling feed direction, and other characteristics. However, in general, CNC milling machines use a rotating spindle to remove unwanted material. They are used to cut hard metals such as steel and titanium, but can also be used for materials such as plastics and aluminum.
CNC milling machines are designed for repeatability and can be used for everything from prototyping to high-volume production. High-end precision CNC milling machines are often used for close tolerance work, such as milling fine molds. While CNC milling can provide fast turnaround, finishing after milling creates parts with visible tool marks. It can also produce parts with some sharp edges and burrs, so if the edges and burrs are unacceptable for these features, additional processes may be required. Of course, the deburring tool programmed into the sequence will remove the burrs.
Precision CNC milling centers are available with multiple axes. 3-axis CNC milling machines utilize the X, Y, and Z axes for a variety of jobs. With a 4-axis CNC milling machine, the machine can rotate and move the workpiece on both the vertical and horizontal axes for more continuous machining. 5-axis CNC milling machines have three traditional axes and two additional rotary axes that enable the workpiece to rotate as the spindle head moves around the workpiece. This allows five sides of the workpiece to be machined without removing the workpiece and resetting the machine.
