5 Key Functions of CNC Machines

A computer numerical control (CNC) machine tool is a machining tool that can process blank material into a desired shape to meet production instructions and part requirements. CNC machines use pre-programmed software to control the movement of complex machinery, including grinders, lathes, mills, and other cutting tools used to remove material. These computer-aided manufacturing technologies perform a variety of complex and precise CNC machining tasks to create manufactured products and specially designed parts for the automotive, defense, and aerospace industries.

Below are a few of the most common industrial applications for CNC machines:

1. Cutting

CNC machines are excellent tools for projects that require precise, efficient cutting speeds, and they can accommodate two of the most advanced cutting technologies: sinker EDM (electrical discharge machining) and wire EDM.

Sinker EDM uses thermal erosion generated by the interaction between two electrodes, one of which is attached to the tool in the form of copper or graphite. The other electrode is a dielectric fluid in which the material is immersed. Amazingly, the tool and the workpiece never come into direct contact during the production process. EDM wire cutting works on the same principle, except that it utilizes a wire electrode as a precise cutting tool.

2. Drilling

This precise hole-drilling process uses a rotary cutting tool, usually a drill or a high-speed water jet, to make circular holes in a stationary workpiece. These holes are usually used for assembly of screws and bolts.

3. Grinding

CNC machines are often equipped with grinding wheels that can polish an almost flawless surface. The accuracy of this subtractive grinding technique greatly exceeds that of any additive manufacturing process, reducing imperfections to 1/10th of the width of a hair.

4. Milling

CNC milling machines are similar to basic milling machines and other manual milling machines in that they use a lathe, water jet, or turning tool to remove material from a stationary blank part. CNC milling machines can move along multiple axes, allowing the operator to perform horizontal, vertical, inclined and face milling tasks with absolute precision. These multi-angle capabilities increase the efficiency of the manufacturing process for complex wood, metal and plastic parts because the machinist can reduce the number of adjustments and refixtures of the blank material.

5. Turning

This CNC machine process works similarly to milling, but instead of fixing the blank to a workstation, it is attached to a high-speed rotating turning mechanism. Workers using lathes or CNC machines with similar attachments will then remove small amounts of material until the blank is machined to the desired shape.