Advances in CAD/CAM Technologies

Abstract

The product development, as a stage of product life cycle, has to meet the requirements enforced by the technological component on one hand, and by the economical one, on the other hand. The technological component enforces restrictions referring to materials, cutting tools, machine-tools foreseen for processing, and mainly to the possibility to work a certain part by the means available. The economical component comes with restrictions referring to the costs of developing the product. It is clear that the two types of restrictions work contrary: in the most cases, the more a material, a tool, or a technology is effective, the more expensive it is. On the other hand, the cheap resources cannot always meet all the technical / technological specific requirements of a certain product. Consequently, a permanent optimisation is necessary. Such an optimisation means finding the best compromise between the technological and the economical criteria. This compromise must lead to producing a product that fully meets all the customer’s technical specifications, and which is attractive in terms of price, as well. Optimisation has to be applied in all the stages of product development, consequently in the simultaneous design – constructive and technological – of the product, and its integrated conception with the production. It is known that the CAD/CAM software is very expensive. Many SME’s that do not use sophisticated hardware resources, and do not use to produce very complicated parts are interested to benefit from low-priced pieces of software that can give answers to the most common problems of designing and manufacturing. Some specific tools that ease the designer’s job in terms of finding the best solution to technological problems, or automating some specific laborious tasks are presented in this chapter. Note that the solutions here provided do not intend to replace the well-known specific software, but rather to be an alternative to it, there where those are not a real necessity. Some samples of problems approached here are automatically checking if a certain part can be machined by up to three axes CNC milling machines, optimizing the approximation of the curves in order to engender automatically CNC files, automatically engendering the tool-path for CNC milling in vertical planes (a new method to compute ball nose milling cutter radius compensation in Z axis for CNC), transferring geometrical data from CAD systems to CAM system (in order to engender CNC files) as a mean of integration of CAD and CAM systems. AutoCAD and AutoLISP were chosen as the support of CAD/CAM systems.