A typical cutting tool in simplified form is shown in Fig. 7.1. The important features to be observed are follows.

Fortunately, the correct cutting speed can estimated with reasonable accuracy from tool-life graphs or form the Taylor tool life Relationship, provided that necessary data are obtainable.

To aim at the research on cutting direction in NC machining of free-form surfaces, a simplified time model for tool trace is established, and the system of tool path programming is discussed.