Uncut free tool path planning for pocket using offset loops

In pocket machining, an optimal tool path planning has been a very difficult problem. In this study, we focus our attention on the integration of complicated tool path planning into clarifying one. Then, we introduced offset loop entity (OLE) as a key concept. The OLE concept enables the proposed offset loop dissection method (ODM) to possess four distinctive features that lead our work to be departed far from the others. Among those, the first is that every kind of intersection is removed by one unique procedure, i.e., OLE dissection. The second is that entire offsetting is performed without taking account of interfering/intersecting relationship with the pocket/island contour curve after the first offsetting had performed. The third is that the devised virtual OLE allows us to treat every kind of island offset loop as same as the pocket offset loop at once. And, the last is that the uncut region is detected in the identical way of offsetting and clean up curve is treated as an ordinary offset loop. To verify prominent features of devised method, prototype systems are implemented and then examined with actual pocket machining. The results show that the use of OLE concept for offset curve generation is a reliable and proper approach, and the proposed ODM fulfils the requirements for uncut free tool path.