Computer numerical control
Computer numerical control (CNC) is the digital manipulation of machines such as drills, lathes and other machine tools by computers and circuitry. Also known as numerical control or computational numerical control, the process comprises a series of numerical values generated by a computer; each of which is assigned to a desired tool or control position to enable the machining of a blank piece of material to precise specifications without requiring a manual operator.
The process dateso back to the first CNC machines built in the 1950s and 60s which relied on punched tape (or perforated paper tape) to communicate the tool position that was controlled by a motor. The process has since been refined and improved by analogue and digital computers.
Under CNC, every object to be manufactured is allocated a G-code (an international standard language) that is stored in the machine and executed by a microcomputer (machine control unit or MCU) attached to the machine. The G-code is a set of instructions – such as the positioning or speed of the tool’s components – that the machine will follow to create or part-create the item in question. Typically, this allows the automation of machine tools such as lathes, mills, routers, lasers and grinders.
In sophisticated manufacturing operations, G-codes are typically derived from the automatic translation of engineers’ CAD drawings into a sequential programme of machine control instructions which are then implemented. A less complex method is writing part-programmes using high-level, part-programming languages.
CNC does not rely on conventional control by cranks, cams and gears. Instead, it allows desired feed rates and cuts to be ‘dialled in’, thereby providing precise, repeatable machine movements that can be optimised for speed, feed and machine cycles.
CNC machines give flexibility of manufacture, especially when variable and complex part geometries are required. Parts can be produced in batches of just a few to several thousand.
[edit] Benefits of computer numerical control
- Provides highly automated, precise manufacturing;
- Does not rely on manual control;
- The part produced is a close match to the original CAD drawing, and
- Gives flexibility of batch size.
[edit] Typical applications of CNC include:
- 3D printing
- Lathes
- Mills
- Water jet cutters, drills, embroidery machines, sheet metal works and glass cutting
- Electrical and/or chemical machining
- Lasers, oxy-fuel and plasma technology
[edit] Related articles on Designing Buildings
- 3D printing.
- Advanced construction technology.
- Building drawing software.
- Building information modelling.
- Common data environment.
- Computer aided design.
- Computer aided manufacturing.
- Computers in building design.
- Computers in tendering.
- Computers in the management of construction.
- Information manager.
- Information and communications technology.
- LEXiCON.
- PAS 1192-2:2013.
- Rapid prototyping.
- Twickenham Studio - London's world-renowned film studio transformed.
- Wikihouse.
Featured articles and news
Electrotechnical excellence, now open for entries.
Net zero electricity grids BSRIA guide NZG 5/2024
Outlining the changes needed to transition to net zero.
CIOB Global Student Challenge 2024
Universitas Indonesia wins for second year running.
New project and cultural district described in detail.
The nature of EPCs, crticism and inaccuracies.
History, issues and redesign.
From waste recycling to energy performance the hierchy.
An introduction to WERCS and WEEE responsibilities
Dealing with 2 million tonnes of waste equipment a year.
Global BACS Market: analytics and optimisation
A BSRIA glance at building automation and control systems.
What it is and how to use it.
Types of insulating plaster by binder and insulant.
Investors in People: CIOB achieves gold
Reflecting a commitment to employees and members.
Scratching beneath the surface; a guide to selection.
ECA 2024 Apprentice of the Year Award
Entries open for submission until May 31.
UK gov apprenticeship funding from April 2024
Brief summary the policy paper updated in March.
For the World Autism Awareness Month of April.