This chapter covers one of the most important and very often misunderstood subject used in modern CNC programming the subject that is in reality very simple; the subject that deals with the methods how to handle the tool diameter (actually its radius) for any given contour toolpath. The subject of this chapter deals with the radius size of the selected cutter as it relates to the actual programmed toolpath, typical applied to contouring.

Incidentally, this subject has been first addressed by the high-level control systems since the early 1980 s. During the time since its conception, the methods of programming has changed a few times. As might be expected, the most current method offers the best combination of programming power as well as programming ease, when this feature is used in program development. In spite of the numerous articles written on the subject over the years, many CNC programmers and CNC operators alike consider this subject as advanced or even very advanced. In spite of the apprehension of some users, the subject of cutter radius versus the contour toolpath can be very simple in everyday situations. Perhaps one of the reasons that gives credence to the impression of this subject as being difficult are the several methods of approach that are available to the CNC programmer as well as some rules associated with these methods. The main purpose of this chapter is to provide explanations and solutions. The general rules apply equally to milling and turning, only the actual methods used to...