CNC stands for Computer Numerical Control and is the practice of converting a design produced by CAD (Computer Aided Design) software into G-Code, CNC Machining language (numbers). The numbers act as coordinates of a graph which controls the movement of the cutter to produce the item.
CNC Machining is used in the manufacturing of both plastic and metal parts. CNC Machining has many benefits; precision is one of these as for manufacturers the precision achieved is much greater than via manual machining. Another benefit is that once the code has been generated it can be repeated in the same manner which provides great opportunities to manufacturers. Additionally, CNC Machining can be used effectively within the production of complex three-dimensional shapes which would be very difficult to achieve with manual machining. As a result, CNC Machining is critical for jobs that require a high level of precision or repetition.
CNC Machining is used in the manufacturing of production and prototype parts for use in product development and engineering. … Firstly, as its name implies CNC Machining involves the use of ‘computer numerically controlled’ machines.
Advantages of CNC Machining
The first major advantage of CNC machining is that it improves automation, removing the need of an operator for all but a few parts of the work. And produces highly accurate parts.
CNC Machining is a process used in the manufacturing sector that involves the use of computers to control machine tools. Tools that can be controlled in this manner include lathes, milling machines, routers and grinders.
CNC Machining Techniques
When fabricating or shaping parts, several techniques are used to remove unwanted metal. Among these are:
- Electrical discharge machining (EDM) also known as spark machining, spark eroding, die sinking, wire burning or wire erosion is a manufacturing process whereby a desired shape is obtained by using electrical discharges (sparks). Material is removed from the work piece by a series of rapidly recurring current discharges between two electrodes.
- Grinding (abrasive cutting) is an abrasive machining process that uses a grinding wheel as the cutting tool, other processes include Surface grinding, cylindrical grinding.
- Multiple edge cutting tools, a cutting tool is any tool that is used to remove materials from the work piece. Cutting may be accomplished by single-point or multipoint tools.
Machining in general is a way to transfer a stock piece of material such as a block of plastic or metal to arrive at a finished product or part by way f a controlled removal process. The CNC machine interprets the design as instructions for cutting. The ability to program the computer device to control the machine tool rapidly advances shop productivity by automating the highly technical data. By way of being able to automate the cutting process this improves both the speed and the accuracy with which the parts can be made.
Types of CNC Machines
These typically fall into two general categories Conventional Technologies and Novel Technologies
Drills – work by spinning a drill bit and moving the bit about and into contact with a stationary block of material.
Lathes – spin the block of material against the drill and putting it into contact with the material by moving a cutting tool until it progressively touches the spinning material.
Milling machines – are probably the most common CNC machining machine tool, this involves using a rotary cutting tool to remove material from the stock unit.
Electrical and/or Chemical Machining technologies to cut material, include Electron Beam Machining, Electrochemical machining, Electrical Discharge Machine (EDM) and Ultrasonic machining. Most of these technologies are highly specialised and are used in special cases for mass-production involving different materials.
Other cutting tools include water-jet cutting technology and plasma cutting machines.
Almost any material can be used in a CNC machining, it really depends on the application. Common materials include aluminium, brass, copper, steel, and titanium, as well as plastics.