Computer-aided manufacturing (CAM) is the use of computer-based software tools that assist engineers and machinists in manufacturing or prototyping product components. CAM is a programming tool that makes it possible to manufacture physical models using computer-aided design (CAD) programs. CAM creates real life versions of components designed within a software package. CAM was first used in 1971 for car body design and tooling. Traditionally, CAM was considered to be a numerical control (NC) programming tool, wherein three-dimensional (3D) models of components generated in CAD software are used to generate CNC code to drive NC machine tools. Although this remains the most common CAM function, CAM functions have expanded to integrate CAM more fully with CAD/CAM/CAE PLM solutions.
As with other ‘Computer-Aided’ technologies, CAM does not eliminate the need for skilled professionals such as manufacturing engineers and NC programmers. CAM, in fact, both leverages the value of the most skilled manufacturing professionals through advanced productivity tools, while building the skills of new professionals through visualization, simulation and optimization tools.
The first commercial applications of CAD were in large companies in the automotive and aerospace industries, for example, UNISURF in 1971 at Renault for car body design and tooling. Integration of CAD with other components of CAD/CAM/CAE PLM environment requires an effective CAD data exchange. Usually, it had been necessary to force the CAD operator to export the data in one of the common data formats, such as IGES or STL, that are supported by a wide variety of software. The output from the CAM software is usually a simple text file of G-code, sometimes many thousands of commands long, that is then transferred to a machine tool using a direct numerical control (DNC) program.
CAM packages could not, and still cannot, reason as a machinist can. They could not optimize toolpaths to the extent required for mass production. Users would select the type of tool, machining process and paths to be used. While an engineer may have a working knowledge of G-code programming, small optimization and wear issues compound over time. Mass-produced items that require machining are often initially created through casting or some other non-machine method. This enables hand-written, short and highly optimized G-code that could not be produced in a CAM package. Over time, the historical shortcomings of CAM are being attenuated, both by providers of niche solutions and by providers of high-end solutions. This is occurring primarily in three arenas:
- Ease of use
- Manufacturing complexity
- Integration with PLM and the extended enterprise
For the user who is just getting started as a CAM user, out-of-the-box capabilities, providing process wizards, templates, libraries, machine tool kits, automated feature based machining and job function specific tailorable user interfaces, build user confidence and speed up the learning curve. User confidence is further built on 3D visualization through a closer integration with the 3D CAD environment, including error-avoiding simulations and optimizations.
The manufacturing environment is increasingly complex. The need for CAM and PLM tools of the manufacturing engineer, NC programmer or machinist is similar to the need for computer assistance of the pilot of modern aircraft systems. The modern machinery cannot be properly used without this assistance. Today’s CAM systems support the full range of machine tools, including turning, five axis machining and wire EDM. Today’s CAM user can easily generate streamlined tool paths, optimized tool axis tilt for higher feed rates and optimized Z axis depth cuts as well as driving non-cutting operations such as the specification of probing motions.
The largest CAM software companies (by revenue by the year 2005) are UGS Corp (now owned by Siemens and called Siemens PLM Software, Inc) and Dassault Systèmes, both with over 10 per cent of the market; CAMWorks, PTC, Hitachi Zosen and Delcam have over 5 per cent each; while Planit-Edgecam, Tebis, TopSolid, CATIA, CNC (Mastercam), SolidCAM, DP Technology’s ESPRIT, OneCNC, and Sescoi between 2.5 per cent and 5 per cent each. The remaining 35 per cent is accounted for by other niche suppliers like T-Flex, Dolphin CAD/CAM, MecSoft Corporation, SurfCAM, BobCAD, Metamation, GibbsCAM and SUM3D.
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