How Do CNC Machines Work?

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1 What is CNC?

Computer Numerical Control (CNC) machines have dozens of business and manufacturing applications. CNC is used in everything from home embroidery machines to robotic arms in a manufacturing assembly plant. Any machine operated by a computer program can be considered a CNC machine. Most CNC machines are now programmed using CAD/CAM software.

2 Programming the CNC

Program a CNC machine by generating G and M codes that the machine understands. The G code is a Go code that tells the machine the precise movements, turns and cuts to make, while the M code turns fluids and other extra devices on and off. These codes are generated with a CAM, or Computer Aided Machining program. More often than not, the CAM program is a part of a CAD, or Computer Aided Design program where the parts are drafted into the computer to exact specifications.

3 Loading the Code

The G and M codes can be saved from the computer and stored on flash or floppy drives to be transferred to the CNC machine. In environments where a large library of codes are stored, punch tape and punch tape readers are still used, as it is simpler to load on small microprocessors. In some cases, the CNC machine operator will create all the needed code directly into the machine. Once the codes are installed, the CNC machine will follow all the directions given to it in the code.

4 Running the CNC

The CNC machine is started and the code program is loaded. The machine operator presses the start button and monitors that the machine is following the design laid out in the code. If a problem occurs, the operator will either stop the machine after the cycle, or if it is serious enough, will hit the "e-stop," or emergency stop button to stop the machine.

5 Uses of CNC

CNC machines are widely used in the fabrication business. Common CNC machine include welders, drills, mills, grinders, routers and lathes. Plasma and water jet cutters, along with other types of cutters are all popular uses for CNC machining. Home uses of CNC machines include electronic paper cutters for scrap booking, quilting and embroidery machines for elaborate designs and DVD title etching programs. The most common use of a CNC machine in the home is the computer printer which operates on the X axis only.