NC machine tool path generation from CSG part representations

Recent improvements in geometric modelling systems hove led to the need for more reliable end highly automated softwore for machine tool path generation. Current machining algorithms require that any port geometric information which cannot be determined from the modelling system be supplied by the user. Much geometric information Is needed i f the model used to represent the pert is incomplete. This Is the case with many conventional boundary representation systems. However, this information can easily be determined automatically I f a solid modelling system is used. This paper presents o method for generating numerically-controlled milling machine tool paths directly from constructive solid geometry part representations. The algorithm requires less user interaction than APT boundary representation methods. A wide variety o f ports may be machined using standard torus (bull) ended milling cutters. The algorithm is computetlonally efficient, end requires iteration only on portions of the part where gouging may occur.