CNC Machining Services

How Does CNC Machining Work?

CNC (Computer Numerical Controlled) Machining is a means to remove material using high speed, precision machines that use a wide variety of cutting tools to create the final design. Common CNC machines include vertical milling machines, horizontal milling machines, and lathes. Complex cylindrical shapes can be manufactured more cost effectively using a CNC lathe versus a 3 or 5-axis CNC milling machine. With a CNC lathe, the part stock turns while the cutting tools remain stationary. Conversely, on a CNC mill, the cutting tools move while the stock remains fixed. To create the geometry of a part, the CNC computer controls the rotational speed of the stock as well as the movement and feed rates of the stationary tools. If square features are needed on an otherwise round part, the round geometry is first created on the CNC lathe followed by the square features on a CNC mill. To successfully make a part on a CNC Machine, programs instruct the machine how it should move. The programmed instructions given to the CNC machine are encoded using CAM (computer aided manufacturing) software in conjunction with the CAD (computer aided design) model provided by the customer. The CAD model is loaded into the CAM software and tool paths are created based on the required geometry of the manufactured part. Once the tool paths are determined, the CAM software creates machine code that tells the machine how fast to move, how fast to turn the stock and/or tool, and where to move in a 5-axis X, Y, Z, A and B coordinate system.

Why Work With Xometry For CNC Machining?

We combine the latest CNC machining and turning processes with proprietary technology to deliver high quality, on-demand parts. Our typical tolerance accuracy ranges from +/-0.001" to +/-0.005" for metal and +/- .002" to +/- .010" for plastic, depending on customer specs. Please see our Manufacturing Standards for more details.