Abstract: A CAD/CAM system arranged so that a re-creation processing for a cutter path is automatically executed by a CAM system when a curved surface is modified by a CAD system. Functions for the cutter path re-creation processing are provided by utilizing a customizing function of the CAD system. In executing computation for the cutter path and in originating NC data, references for assigning the functions are previously set for the curved surface. When the shape of the curved surface is modified on the CAD side after the NC data has been created, the CAM is invoked to invoke the aforesaid functions. Perceiving this invocation, the CAM executes the cutter path re-creation processing by using machining condition data set for the unmodified curved surface, on the basis of the invoked functions. Thus, the cutter path for the modified curved surface is created immediately by the CAM when the curved surface is modified by the CAD.

Abstract: Provided is a method of creating NC for rough machining using surface data obtained by digitizing a model surface. A traveling distance Ki is determined between a present target tool position (Pck') and an immediately preceding tool position [PC(k-1)']. When the distance ki is less than a predetermined value L, NC data for rough machining are created in such a manner that a tool will move linearly between the present tool position (Pck') and the immediately preceding tool position [Pc(k-1)']. When the distance Ki is greater than the predetermined value L, the distance is partitioning into a plurality of set distances l.sub.0, and a check is made at each partitioning point (Pnj) to determine whether the tool (TL) will intersect a shape approximating surface (Sm).

Abstract: This invention relates to a method of creating NC data for rough machining, in which a cutting path (QLi) for rough machining is outputted using points on an i-th point sequence path (PLi) from among a plurality of point sequence paths repeatedly digitized at a predetermined interval in a predetermined direction. The next cutting path for rough machining is created and output using a projected point sequence path (PLk') which, among those projected point sequence paths spaced away from the i-th point sequence path by a distance greater than a tool radius (Tr), is that nearest an i-th projected point sequence path (PLi').