Computer-aided manufacturing

Overview

Sometimes the CAM software is integrated with the CAD system, but not always. Every piece of CAM software must first solve the problem of CAD data exchange where in the CAD system which is producing the data often stores it in its own proprietary format, much as is the case with word processor software. Usually it is 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.

While it has long been the dream to make the CAM software that can run on its own, it generally requires a human operator with much knowledge and skill of machining to select the Milling cutters and define the necessary parameters and strategies that will generate an effective tool path.

Shortcomings

Present day CAM software has several shortcomings that necessitate skilled CNC machinists in industry. CAM software must output code for the least capable machine, as each machine tool interpreter may add on to the standard g-code set for increased flexibility. In some cases, such as improperly set up CAM software or specific tools, the CNC machine will require manual editing before the program will run properly. None of these issues are so insurmountable that a thoughtful engineer cannot overcome for prototyping or small production runs; G-Code is a simple language. In high production or high precision shops, a different set of problems are encountered where an experienced CNC machinist must both hand-code programs and run CAM software.

As CAM packages cannot reason as a machinist can, they cannot optimize toolpaths to the extent required of mass production. 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 can't be produced in a CAM package.

Job Elimination Concerns

CAM demonstrates the latent drive towards computerization that is just now touching manufacturing, where in other industries it has prevailed and matured. This has lead to a concern amongst skilled workers that computers will replace future generations of machinist as engineers become versed in CAM. At least in the United States, there is a shortage of young, skilled machinists entering the workforce able to preform at the extremes of manufacturing; high precision and mass production. As CAM software and machines become more complicated, the skills required of a machinist advance to approach that of a computer programmer and engineer rather than eliminating the CNC machinist from the workforce.

Software providers today

The largest CAM software companies (by revenue 2005) are UGS Corp and Dassault Systèmes, both with over 10% of the market; PTC, Hitachi Zosen and Delcam have over 5% each; while Planit, Tebis, Missler, CNC (Mastercam), ESPRIT and Sescoi between 2.5% and 5% each. The remaining 35% is accounted for by other niche suppliers like OneCNC.

Areas of usage
* In mechanical engineering
* In electronic design automation, CAM tools prepare printed circuit board (PCB) and integrated circuit design data for manufacturing.

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