“CNC” stands for Computer Numerical Control. A CNC machine is an electro-mechanical device that controls, automates and monitors the movement of shop tools with computer programming inputs. These advanced machines can generate physical prototypes from a digital software file and are often compared with 3D printers.
CNC machines were first developed in the 1940s and have been used in manufacturing across the globe ever since. In this used CNC machine guide, you’ll also learn how they work and how many different types of used CNC machines exist.
HOW DOES A CNC MACHINE WORK?
Industrial CNC machines generally have a dedicated onboard controller to execute programmed motions. The computer controller communicates with drive components and motors to move and control the CNC machine’s axes, while the feedback system monitors the speed and position to adjust as necessary.
All of these motions and adjustments are dependent on the digital instructional data that is inputted into the machine. Data that is typically used for CNC machines is inputted using either computer-aided manufacturing (CAM) or computer-aided design (CAD) files. The benefit of being able to program computers to control machine tools drastically increase shop productivity with the automation of especially technical or labor-intensive processes.
WHAT ARE THE DIFFERENT TYPES OF CNC MACHINES?
All CNC machines can work with most materials (like wood, metal, fiberglass, foam and plastic), but depending on the type of actions you need the machine to execute, you’ll need to consider the different types of machines available. As a general CNC machine guide, here are some of the most common types of CNC machines, what they’re used for and what brands you should consider when making a purchase:
What They Do: CNC lathe machines spin a block of material against a drill bit—essentially the opposite of a drill.
Benefits of CNC Lathes:
- Provides a simulated visualization of the machine’s process
- Requires less intimate knowledge of the machine than older types
- Can be set and operated by the same person
SWISS-STYLE CNC LATHES
Benefits of Swiss-Style CNC Lathes:
- Provides extreme accuracy
- Ideal for slender workpieces and small-diameter parts
- Capable of fast cycle times
Popular Swiss-Style CNC Lathe Brands: Citizen, Star, Tsugami, Miyano, Nomura, KSI, Hanwa and Tornos
CNC HORIZONTAL MACHINING CENTERS
What They Do: CNC Machining centers work by clamping down a stationary piece of material and spinning a drill bit into contact with the material. Horizontal machining centers have a horizontally oriented spindle.
Benefits of CNC Horizontal Machining Centers:
- Favors uninterrupted production work
- Horizontal orientation encourages chips to fall away without being cleared manually
- Allows a pallet change to be incorporated for space efficiency
Popular CNC Horizontal Machining Center Brands: Mazak, DMG Mori, Mori Seiki, Okuma, OKK, Haas, Doosan, Hyundai-Wia, Toyoda, Kitamura, Matsuura, Hurco, Nakamura-Tome, Makino, Enshu, Mitsui Seiki, YCM, Tsugami, Chevalier and Mighty Viper
CNC VERTICAL MACHINING CENTERS
What They Do: CNC vertical machining centers have a vertically oriented spindle, enabling tools to stick straight down and cut across the top of a piece of material. Vertical machining centers use rotary cutters to remove material from a piece. This process is also often referred to as milling.
Benefits of CNC Vertical Machining Centers:
- Can add a rotary table to provide 4-axis machining
Popular CNC Vertical Machining Center Brands: Mazak, DMG Mori, Mori Seiki, Okuma, OKK, Haas, Doosan, Hyundai-Wia, Toyoda, Kitamura, Matsuura, Hurco, Fanuc, Brother, Makino, Enshu, Mitsui Seiki, YCM, Tsugami Fadal, Chevalier and Mighty Viper
5-AXIS CNC MACHINING CENTERS
What They Do: 5-Axis CNC machining centers can move cutting tools in five different directions. The tools are able to move along the X, Y and Z linear axes as well rotate on A and B axes to contact the material from any direction.
Benefits of 5-Axis CNC Machining Centers:
- Provides infinite possibilities in part sizes and shapes
- Ability to process five sides of a part in a single setup
- Features high efficiency and precision
- Widely used in aerospace, military and high-precision medical device industries
Popular 5-Axis CNC Machining Center Brands: Mazak, DMG Mori, Mori Seiki, Okuma, OKK, Haas, Doosan, Mikron, Hyundai-Wia, Agie Charmilles, Toyoda, Cincinnati, Kitamura, Matsuura, Hurco, Makino, Enshu, Mitsui Seiki, YCM, Brother, Chiron and Fanuc
CNC HORIZONTAL BORING MILLS
What They Do: CNC boring mills make (or bore) holes in a piece of material. The table type is considered the most common and versatile of boring mills, but there are also planer and floor types. A horizontal boring mill bores holes in a horizontal direction.
Benefits of CNC Horizontal Boring Mills:
- Versatile for heavy-duty or high-precision components
Popular CNC Horizontal Boring Mill Brands: Kuraki, Toshiba, Giddings and Lewis (G&L), Awea, Bullard, Cincinnati, Doosan, Femco, Mighty Viper, Milltronics, SNK Nissin, Ikegai and Wotan
CNC VERTICAL BORING MILLS
What They Do: Also referred to as vertical turning lathes, vertical boring mills make holes in a vertical direction. These machines typically include rotary, horizontal worktables and a cross rail mounted above the worktable.
Benefits of CNC Vertical Boring Mills:
- Capable of handling heavier and awkward-shaped workpieces
CNC ELECTRONIC DISCHARGE MACHINES (EDM)
What They Do: Electrical discharge machining goes by many names, such as spark eroding, die sinking, spark machining, burning, wire burning, etc. There are also two different types of CNC EDMs: wire EDM and sinker EDM. The EDM process is defined by removing material from a workpiece by a series of rapidly recurring current discharges between two electrodes. These electrodes are separated by a dielectric liquid that enhances electric voltage. The main difference between wire and sinker EDM is that in sinker EDM, the material is submerged in an insulating liquid, and in wire EDM a single-strand brass wire is submerged and used to cut the workpiece.
Benefits of CNC EDMs:
- Creates complex shapes that would otherwise be difficult to produce
- Ideal for small workpieces that could be damaged by tool pressure
- No direct contact between tools and workpiece
Popular CNC EDM Brands: Makino, Sodick, Agie Charmilles, Mitsubishi, Accutex, Ona and Fanuc