How Does a CNC Machine Work?

CNC, computer numeric control, machine systems are a type of machining equipment controlled by computers. In a nutshell, computer aided design (CAD) software is used to produce a design for a part to be machined. This design is translated into numbers and coordinates. The CNC machine system can then "read" these instructions and move the machining tools to the precise coordinates. Thus, the parts are cut and shaped to the exact specifications of the design, every time.
 
Alas, there's more to the story as qualified operators also play a role. Let's take a quick look at the history of CNC machining and the other important components to successful CNC operations.
 
A Brief History of CNC Machines
Numeric control machines have been in existence since the 1950s, getting their instructions from punched tape. The idea eventually caught on with manufacturers, but each wanted to create its own language. In the 1960s, a standard language, G-Code, was adopted and standardized for part programs. At the same time, computer aided design arrived on the scene, as did a few affordable mini-computers. As the economy slowed and labor costs rose in the 1970s, companies gravitated toward CNC machining.
 
Advances in personal computers and cheaper, more powerful microprocessors soon followed, opening CNC to markets of all sizes including to hobbyists. Today, numerous CNC software exists including open source CNC software.
 
How CNC Machines Work
In order to begin cutting parts, the machine must have instructions to follow. Remember that G-Code that was standardized in the 1970s? This is a "Go" code that tells the CNC machine where to go, at which point to turn, and when to cut. M codes are used to tell the CNC machine when to turn on additional devices or add fluids. These codes are generated by CAM software and then loaded onto the machine via flash storage devices or even Wi-Fi if so equipped.
 
Once the CNC machine is loaded, the CNC operator will need to place the component to be cut into the machine, preparing and securing it as needed. From there, the machine operator will start the CNC machine and monitor operations. The CNC machine will follow its instructions, making the CNC operator's job at this point fairly easy. However, supervision is a must in case a problem occurs that needs troubleshooting.
 
What are CNC Machines Used For?
CNC machines are used to create all kinds of products and components. CNC machines can be used to cut metal, acrylic, and other materials into precise shapes, drill holes, and grind surfaces to precise specifications. They can be used to engrave items, embroider items, cut leather, and more. From auto parts, nuts, and bolts to trophies, engraved tags, and more, CNC machining is used to create many of the components used in manufacturing. For example, if you have the iPhone 5c, your iPhone's colorful shell was CNC'd. If you own an inkjet printer, it is a basic CNC machine that moves the printhead along the X axis according to instructions sent to it whenever you press the "print" button.

Adrian Thomas has worked with many CNC machine shops around the San Francisco Bay Area. He has gathered sources from http://www.acrylicart.com/precision-cnc-machining.html to write this article and feel free to connect with him over at Google+.