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More about CNC Machining

cnc milling machine

CNC machining is a manufacturing procedure that uses computer programs to control a range of machining centres such as lathes, milling machines, drills, routers and grinders designed for material removal.

Machines are programmed offline or directly to produce precision engineered components in various materials and for a multitude of applications.

A computer program defines the tool path using traditional CAD drawings or now, more commonly, 3D models and works out the most efficient cutting path, tool type, speeds and feed configurations.

A series of servo motors and lead screws guide the cutting tool position, type, movement and orientation to replicate the encoding program.

Uses of CNC machining

CNC machines are used across the full spectrum of metal engineering processes such as turning, milling and laser cutting.

Once programmed, and with proven set up completed, CNC operations are executed with virtually no involvement from human operators resulting in very high precision engineering and consistent repeatability.

The program not only controls the precision CNC machining process but also determines subsidiary functions such as fixtures and machine axes.

CNC machining can manufacture parts for all sectors of industry, but especially where complex multi-axis machining is required for precision fabricated products such as those used in the aerospace, defence, medical, transport sectors as well as for vending machine and kiosk manufacture.

CAD drawing and CNC machining

CNC machining typically starts with a 3D design of the finished machined object, which is used to generate machine instructions.

Component dimensions generated by computer-aided design (CAD) software are converted into a proposed product using computer-aided manufacturing (CAM) software, often combined into CAD/CAM systems.

The computer program is loaded into the CNC machine along with the relevant tooling and a first off sample is manufactured to confirm dimensional accuracy and finish. Minor adjustments can then be made to the program as required.

Advantages of CNC machining

There are many advantages of CNC machining in the precision engineering and sheet metal manufacturing environment:

  • Precision components: The use of a digital template and the autonomous machining practically eliminate human error and achieve accuracy of 1/1000th.
  • Consistency of manufacture: CNC machining will produce consistent components and, with the application of some additional measurement and monitoring, can also automatically detect tool wear, material inconsistencies and dimensional creep.
  • Reliable endurance: CNC machines can work around-the-clock daily, weekends and holidays. They only need to stop for maintenance or repair.

Previously, complex machined components required several machining operations resulting in part variations, increased cycle times and higher costs.

Not only is CNC machining more efficient it can also reduce waste and bring down production times, especially for large batch run-off precision engineered components.

Types of CNC machining tools

Basic CNC machining tools include turning centres (lathes), Swiss-style turning, bridge mills and gantry mills, metrology tools, shapers, broaching machines and 5-Axis machine tools. See our article on Types of CNC Machining Tools for more details.

A complex machined component will usually require several machining operations in its construction, and these are typically executed in a particular order.

Many modern CNC machines can combine different engineering operations and machine tools into a single cell.

Advanced machines can operate on up to five axes, laterally along the x and y-axes, longitudinally along the y-axis and rotationally about one or two axes.

Multi-axis simultaneous machining allows the machining of complex shapes with relative ease. Multi-axis machines can also have the capacity to flip components parts over to turn them around, eliminating the need for any manual intervention.

No matter which setup or type of machine used, a single CNC program can control all the metal engineering and fabrication operations that are required such as cutting, drilling, turning, milling, routing, punching and welding.

The scope of CNC machining

The precision and versatility of CNC machining means that CNC machined parts are used in a wide range of products manufactured from an extensive range of materials, including most metals and plastics.

Complex machined parts can be produced from a single machine to very high levels of accuracy while advances in CAD/CAM software and the digitisation of supply chains means that production times have become very much shorter than conventional production methods.

KMF Precision Engineering is an advanced precision engineering company at the forefront of CNC machining services and manufacturing technology. Focused on investment and innovation, KMF Precision Engineering is a market leader with best-in-class manufacturing facilities and technology, allowing us to excel in the production of high-value and quality-stringent CNC machined components at competitive costs and lead times.

If you have a CNC machining project you would like to discuss, please get in touch with our team today: sales@kmf.co.uk | 01780 593020.

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