CNC routers and 3D printers achieve similar results in different ways. A CNC (computer numerical control) router uses computer-controlled tools to cut material away from a raw block. In contrast, 3D printers add lots of layers of material together to create a whole. Both processes are often used as printing services for anything from signs to frames, and they each come with certain advantages and drawbacks. Here are just four reasons why you might want to consider CNC machining over 3D printing.