Short for ‘Computer Numerical Control’, CNC machining is a computer-directed manufacturing process. It can control a wide variety of machinery, from grinders and mills to lathes, routers, and more. Because CNC can be used to shape materials with greater speed and accuracy than manual controls, it has become a leading metal fabrication technology.
How does CNC machining work?
When numerical control machines originally appeared during the 1940s, they used motors to control tool movement. As the technology developed, these mechanisms were augmented by analog computers and finally digital computers.
Today, CNC machines are controlled by a special software programmed with G-Code, a process-specific language that enables precise control of features like coordination, location, speed, and feed rate. After a 2D or 3D CAD drawing is created and translated into computer code, operators program the chosen cuts into the software, which then directs the connected tools and machinery to carry out processes such as:
- Laser cutting
- Ultrasonic welding
Tool position and speed are both pre-programmed and require little to no involvement from shop operators. The result is a consistency in output that would be difficult to replicate manually, especially when more complicated cuts have to be made at various angles and levels on the workpiece.
What are the different types of CNC machines?
Below is an overview of the most common CNC machine types, along with their unique functions.
- CNC Mills: After materials are placed inside a CNC milling machine, its built-in drilling and cutting tools follow inputted guidelines to create the finished product. Milling machines are routinely used to drill, plan, route, bore, cut gears and produce slots.
- CNC Lathes: CNC lathes produce detailed designs that couldn’t be produced on manually run versions. A lathe in the center of the machine rotates and moves the material into the position directed by the computer.
- CNC Plasma Cutters: With plasma cutters, the material is shaped with a plasma torch. Since they cut with a very hot and localized cone, they are especially useful for cutting sheet metal in angled or curved shapes. (Although the edges are much rougher than if they were cut with a laser.)
- CNC Laser-Cutting Machines: These machines use one of three types of lasers- CO2, neodymium, or yttrium-aluminum-garnet- to cut through materials. Although not as strong as plasma torches, lasers still offer a high degree of cutting accuracy.
- CNC Electric Discharge Machine: Also known as spark CNC machines, these units use electrical sparks to shape materials, with the computer dictating how much electrical discharge the electrodes produce.
Horizontal vs. vertical machining centers
One of the latest innovations in CNC technology is the VMC (vertical machining center) machine, which has a vertically-oriented spindle instead of the traditional horizontal one. These machines, which boast capabilities of 1000psi, can be designed with a 4th or even 5th axis for greater production versatility compared to their horizontal counterparts. VMC is regarded as the most suitable technology for processing cover, plate, and plate-type parts.
Other VMC advantages include:
- Gravity advantage: in metal machining, water needs to be poured on the spindle, and the vertical position helps the water reach its target more effectively.
- Operator access to the machine chamber, where processing conditions can be observed.
- Simpler to use than horizontal machining centers while delivering a more versatile performance.
- Easier debugging.
- Less expensive to acquire and use, creating a cost savings that can be passed on to customers.
Are there non-metal CNC machines?
Although CNC machines are primarily used to shape and finish metal, they can process other materials. Wood CNC machines are similar to hand-controlled mills, except that they use computer-driven routers to direct the tasks of panel saws, boring machines, spindle moulders, and other woodworking machinery. Other materials that can be processed using CNC technology include:
With its ability to work with so many materials, CNC machining is an essential function of the manufacturing sector, from the production of tools and auto parts to computer and aerospace components. Without the high-tech capabilities that it offers, a lot of the items that we see and use today would be next to impossible to produce.
Contact a CNC Machining Specialist
At Advantage Machining, we stay ahead of the curve when it comes to machining and manufacturing technologies. Our CNC machines are programmed to each customer’s exact specifications, resulting in custom and repeatable machining jobs that meet deadlines and exceed expectations. Let us put our nearly two decades worth of experience to work for you. Contact us today by calling 289.389.3167 or submitting a form on our contact page.