What Does CNC Stand For?
CNC Machining is a vital element to the core processes of manufacturing, but what does CNC mean? Well, the term CNC means “Computer Numerical Control”, which is the automated control of machining tools.
Developed in the 1940s, NC (Numerical Control) machines relied on a technology known as “Punched Tape”. As the name implies, Punched Tape was code punched onto Tape, which fed into the machines. More about Punched Tape here.
Punched Tape is long gone as time transitioned to analogue, then digital computers in the 1960s and 1970s.
NC Machines were created to build helicopter blades and stiffer skins for aircraft. Today, with their improved efficiency, CNC machines are suitable for many industries. Some of these industries include:
It can offer a range of products, such as
- Automobile Parts Including Frames, Engine Components etc
- Surgical Equipment
- Aeroplane Parts
- Gears, Chains, Sprockets etc
- Hand Tools
What Exactly Is CNC Machining?
CNC Machining is a fabrication method that uses a motor-driven machine controlled by a computer. The subtractive process removes material from a workpiece in order to produce a custom-designed part or product.
Computer software is pre-programmed to tell a device on cutting trajectories and tooling. The machine receives its instructions from computer-aided design (CAD) software or computer-aided manufacturing (CAM) software. Once the software is programmed and loaded, the CNC machine will operate independently, and very little human input is needed.
Instructions delivered to the CNC machine is in a sequential program of machine control instructions. Many programming languages are used today, including G-code and M-code (More on G-Code and M-Code below).
Some examples of CNC Machines:
- Milling Machines
- Laser Cutters
- Waterjet Cutters
- Sheet Metal Makers
- Slumping Machines and more
Types of CNC Machining
Some everyday CNC machining operations are –
- CNC Drilling – Drilling uses rotating drill bits to produce the circular holes in the workpiece. There are various kinds of drill bits with each having a specific application.
- CNC Milling – Milling employs rotating cutting tools to shape the workpiece. Milling tools can be either horizontally or vertically oriented. Primary mills are capable of three-axis movements, and the more advanced models can provide more axes.
- CNC Turning – Turning uses single-point cutting tools to remove material from the spinning workpiece. Tools available for roughing, finishing, facing, threading, forming, undercutting, parting, and grooving applications.
- CNC Grinding – Grinding uses a rotating wheel to remove material from a piece of metal. As the method can achieve a high-quality finish, it’s usually one of the last operations the part goes through.
- CNC Routing – Routers work very similarly to milling by using a rotating piece as the cutting head. However, the difference separating the two is the materials it works with. Routers are more suited to softer materials, such as wood.
How CNC Machining Works
Modern CNC machines are fully computerised, taking instructions from CAM or CAD software. It provides the machine with a set of coordinates that guides the cutting head during the manufacturing process.
The machining processes need many tools to produce a part. The Machinists can build digital tool libraries that work with the physical machine. As a result, the CNC machinery can automatically change tooling based on digital instructions.
The CNC machining process starts with creating parts in CAD (computer-aided design). Once the 3D model is built, the basic dimensions and properties are determined.
CAM (computer-aided manufacturing) software prepares the model for the entire fabrication process.
First, it checks the model for faults, then the correct parameters are set. These include cutting speed, voltage, RPMs, etc.
The software then determines the orientation and placement of parts relative to raw material, known as Nesting.
All this information is turned into a language, or code, that the machinery can understand. The standard codes are called G-Code or M-Code.
What Is G-Code?
The correct name of the code is RS-274D, but most people refer to it as G-Code. G-code is a programming language that instructs a CNC machine on what to do or how to do something. The “G” in G-Code stands for Geometric.
Every row of code tells the machine to do one action. These actions can include rotation, speed, positioning etc.
What Is M-Code?
Used in combination with G-Code, M-code controls the non-geometry functions of the machine. For example, coolant on and off, spindle start and stop etc. These functions may vary by the particular type of machine.
Like G-code, M-code consists of an “M” and a number. The M tells the machine that a miscellaneous command follows. Yet, Unlike G-code, M-code can be more specific for different devices and is more adaptable.
CNC Machining At Varlowe Industrial Services
Our CNC Machining department consists of a team of skilled and experienced machinists.
We are also one of the few companies offering a CMM Inspection Service. Our CMM Inspection services use the latest technology to record the precise measurement of an object. You can read more about the advantages of CMMs in our blog post, “What Is CMM?“.
For more information, please email email@example.com, or call us on 01902 861042.