CNC Laser Cutting | CNC Punching

The St. Ann's Sheet Metal Company, based in Nottingham, has been trading since 1960. In this time we have built up a reputation as a quality orientated sheet metal company in materials, workmanship and customer support recognised by ISO 9002 accreditation, to achieve this we use state of the art technology combined with a determination to succeed, thus enabling us to give our customers a highly competitive advantage.

Apart from our precision laser cutting service, St Ann’s Sheet Metal specialise in light to medium fabrication work, CNC punching and bending facilities. We can also offer competitively priced precision machining, quality powder coating and plating processes. St. Ann's Sheet Metal are able to satisfy customer needs efficiently and competitively.

How does Laser Cutting work?

It works by melting, burning or vaporising the material, while an assist gas is employed to "clear" the cut zone of the molten / burnt material or the gas vapour. In the early days the setting of the laser to produce the desired effect was very much a manual process and very complex.

The cutting process is very complex, but basically involves pre-piercing the material outside the area of desired cut, moving the laser beam into the cutting area to apply heat, and finally use an assist gas to remove the heated material and produce the cut. The type of assist gas employed is critical, and is dependent on the material to be laser cut; most commonly used are Oxygen (used predominantly for carbon steels), Nitrogen (used for non-ferrous steels & non-metals) and Argon (used for more exotic materials such as titanium), but we also have the capability to cut in Compressed Air on most materials 2mm thick or under.

The latest machines now come with many of the common parameters pre-programmed, allowing much easier setting. However, the variations in batches of material lead to serious issues in cut quality, and operators still require many hours of training to run a laser efficiently and economically Industrial machines are predominantly used to cut parts from flat-sheet material. However, there are machines specially adapted to cut tubular components, and multi-axis lasers used to cut pre-formed components.

Limitations When Using on Sheet Metal

Despite the numerous advantages of laser profiling, it is not always the most appropriate or most cost-effective method of producing a sheet metal blank.

CNC Punching is a cost effective way of making components out of sheet metal. CNC Punching machines have lower capital cost than lasers and they do not use electric power to nearly the same extent (nor do they have the need for various cutting gases). It is also true that no laser machine can compete with punching in the speed of producing a large number of similar holes or slots.

CNC Punching machines have lower capital cost than lasers and they do not use electric power to nearly the same extent (nor do they have the need for various cutting gases). It is also true that no laser machine can compete with punching in the speed of producing a large number of similar holes or slots. Equally, some jobs do not require the fine edge finish provided by laser. CNC punching can therefore sometimes offer a viable and economical alternative.

The abbreviation CNC stands for computer numerical control, and refers specifically to a computer "controller" that reads G-code instructions and drives a machine tool, a powered mechanical device typically used to fabricate components by the selective removal of material. CNC does numerically directed interpolation of a cutting tool in the work envelope of a machine. The operating parameters of the CNC can be altered via software load program.

In a production environment, a series of CNC machines may be combined into one station, commonly called a "cell", to progressively machine a part requiring several operations. CNC machines today are controlled directly from files created by CAM software packages, so that a part or assembly can go directly from design to manufacturing without the need of producing a drafted paper drawing of the manufactured component. In a sense, the CNC machines represent a special segment of industrial robot systems, as they are programmable to perform many kinds of machining operations.

www.saintanns.co.uk