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CAM: Computer Aided Manufacturing

Definition: Computer-Aided Manufacturing (CAM) is the use of computer software and hardware in the translation of computer-aided design models into manufacturing instructions for numerical controlled machine tools.

Applications of Computer-Aided Manufacturing

The field of computer-aided design has steadily advanced over the past four decades to the stage at which conceptual designs for new products can be made entirely within the framework of CAD software. From the development of the basic design to the Bill of Materials necessary to manufacture the product there is no requirement at any stage of the process to build physical prototypes.

Computer-Aided Manufacturing takes this one step further by bridging the gap between the conceptual design and the manufacturing of the finished product. Whereas in the past it would be necessary for a design developed using CAD software to be manually converted into a drafted paper drawing detailing instructions for its manufacture, Computer-Aided Manufacturing software allows data from CAD software to be converted directly into a set of manufacturing instructions.

CAM software converts 3D models generated in CAD into a set of basic operating instructions written in G-Code. G-code is a programming language that can be understood by numerical controlled machine tools – essentially industrial robots – and the G-code can instruct the machine tool to manufacture a large number of items with perfect precision and faith to the CAD design.

Modern numerical controlled machine tools can be linked into a ‘cell’, a collection of tools that each performs a specified task in the manufacture of a product. The product is passed along the cell in the manner of a production line, with each machine tool (i.e. welding and milling machines, drills, lathes etc.) performing a single step of the process.

For the sake of convenience, a single computer ‘controller’ can drive all of the tools in a single cell. G-code instructions can be fed to this controller and then left to run the cell with minimal input from human supervisors.

Benefits of Computer-Aided Manufacturing

While undesirable for factory workers, the ideal state of affairs for manufacturers is an entirely automated manufacturing process. In conjunction with computer-aided design, computer-aided manufacturing enables manufacturers to reduce the costs of producing goods by minimising the involvement of human operators.

In addition to lower running costs there are several additional benefits to using CAM software. By removing the need to translate CAD models into manufacturing instructions through paper drafts it enables manufactures to make quick alterations to the product design, feeding updated instructions to the machine tools and seeing instant results.

In addition, many CAM software packages have the ability to manage simple tasks such as the re-ordering of parts, further minimising human involvement. Though all numerical controlled machine tools have the ability to sense errors and automatically shut down, many can actually send a message to their human operators via mobile phones or e-mail, informing them of the problem and awaiting further instructions.

All in all, CAM software represents a continuation of the trend to make manufacturing entirely automated. While CAD removed the need to retain a team of drafters to design new products, CAM removes the need for skilled and unskilled factory workers. All of these developments result in lower operational costs, lower end product prices and increased profits for manufacturers.

Problems with Computer-Aided Manufacturing

Unfortunately, there are several limitations of computer-aided manufacturing. Obviously, setting up the infrastructure to begin with can be extremely expensive. Computer-aided manufacturing requires not only the numerical controlled machine tools themselves but also an extensive suite of CAD/CAM software and hardware to develop the design models and convert them into manufacturing instructions – as well as trained operatives to run them.

Additionally, the field of computer-aided management is fraught with inconsistency. While all numerical controlled machine tools operate using G-code, there is no universally used standard for the code itself. Since there is such a wide variety of machine tools that use the code it tends to be the case that manufacturers create their own bespoke codes to operate their machinery.

While this lack of standardisation may not be a problem in itself, it can become a problem when the time comes to convert 3D CAD designs into G-code. CAD systems tend to store data in their own proprietary format (in the same way that word processor applications do), so it can often be a challenge to transfer data from CAD to CAM software and then into whatever form of G-code the manufacturer employs.

Further information regarding computer-aided manufacturing can be found at the Berkeley CAM Research site, UC Irvine’s CAM resource site and the National Institute of Standards and Technology (NIST) (PDF).