Computer numerical control milling, or CNC milling, is a highly-sophisticated machining process that utilizes computerized controls and rotating multipoint cutting tools to gradually remove material from the workpiece and fabricate a custom-designed product or component. This manufacturing process is 100% fitting for machining a broad range of manufacturing materials like plastic, metal, wood, and glass.
In fact, we can say that CNC milling is responsible for revolutionizing the machining scene, granting the possibility to mass-produce detailed products and components faster and with more accuracy than conventional machining methods. Furthermore, once the CNC milling machine is set and programmed, the operator can produce more milling parts and components at faster speeds with fantastic part-to-part repeatability, making CNC milling ideal for high-volume manufacturers.
This brief article focuses on the CNC milling process, outlining the basics and how the process works to serve you as a good starting point if you’re wondering if you should switch the outdated methods of production you’re currently using with something new cost-efficient like CNC milling.
CNC Milling Machines And How They Work
In a nutshell, milling is the process of drilling and cutting a given material with the help of a CNC milling machine which utilizes a rotating cylindrical tool called a milling cutter. The milling cutter is held in a spindle and can vary in size and form. However, the most significant difference between a CNC milling machine and any other drilling machine is the milling machine’s ability to cut at different angles and move along different axes. For that reason, there are different kinds of CNC milling machines, all distinctive by the number of movement axes:
- 2-axis CNC milling machines. These CNC milling machines can cut slots and holes in the X and Z axes, or in other words, 2-axis CNC milling machines will only cut horizontally and vertically in one direction.
- 3-axis CNC milling machines. 3-axis milling machines are the most common on the market, and besides the X and Z axes, they add the Y-axis. With 3-axis milling machines, you can cut vertically and in any direction, but an object like a sphere needs to be one half at a time.
- 4-axis CNC milling machines are even more complex because they can rotate the X-axis, similar to a lathe.
- 5-axis CNC milling machines include rotation in both the X- and Y-axis and are the most complete CNC milling machines you can work with. They allow you to shape aerospace structures, car models, medical products, and everything you can imagine.
CNC Milling Methods
CNC milling is a subtractive manufacturing method, which means that the material is removed from the workpiece to produce the final design shape. The entire process begins with a CAD drawing or 3D model of the final component. Afterward, the dimensional data is exported into a language that CAM software can understand. Then, the CNC milling machine “reads” the generated CAM instructions and carries a series of precise machine movements along different axes and paths. Nevertheless, there are various methods of CNC milling, with the four most common including:
- Plain or surface milling, a milling method that utilizes a cutting tool to remove material along the surface of the workpiece where the rotation axis is parallel to the workpiece.
- Face milling is a method that utilizes a rotational axis perpendicular to the material’s surface.
- Angular milling is a method that positions the cutting tool’s rotary axis at an angle to the workpiece surface to produce angular cuts as specified by the complex design.
- Form milling is a method that makes non-flat cuts, like curves, contours, and radii.
CNC Milling Materials And Applications
The most significant benefit of CNC milling is its ability to cut a broad range of materials and produce custom-designed parts and products in much faster production time cycles than conventional machining. In addition, it can be utilized to machine parts from a wide variety of materials like:
- Different metals, including aluminum, beryllium, brass, bronze alloys, carbon steel, copper, iron, nickel, stainless steel, steel alloys, and titanium.
- Exotic and precious metals like monel, inconel, platinum, silver, and superalloys.
- Plastic materials like acetal, ABS, acrylic, nylon, fiber-reinforced plastics, phenolic, polycarbonate, polyether ketone, PTFE, PVC, and Teflon.
CNC milling can be utilized within any industrial sector that requires exact components, including complex industries like military, automotive, and aerospace.
Final Words On CNC Milling
Outlined above are the basics of the milling process, from how it works to the different types of CNC milling machines, the various CNC milling methods, materials, and applications. Now that you know how CNC milling works, you can easily make better decisions on your next manufacturing projects and include this revolutionary machining process into your production arsenal.
