New NC Routines for Quality in Milling

This paper illustrates some developments in NC programming routines for pockets. Where previous work focused on choosing optimum speed and feed, this work addresses the need to select proper axial and radial depths of cut. First, it is shown that in pocketing operations, acceptable depths of cut can change as the direction and mode (UP-or down-milling) changes. It is therefore advantageous to have pocketing subroutines which allow for that fact. A database suggesting appropriate cutting parameters to produce given quality criteria has been developed using measured dynamics and time-domain simulation. The tool path is automatically selected using this database and optimizing metal removal rate. Additional improvements were made by choosing the tool path to avoid the necessity of internal corners, since the change in radial depth of cut there changes the quality of the part.