Pre-Process Evaluation and Modification of NC Program Using Virtual Machining Simulator.

A PC based virtual machining simulator (VMSim) has been developed to evaluate and modify the NC program before the real machining. The VMSim consists of an NC program simulator, a geometric simulator and a physical simulator. The NC program simulator can calculate the machining time and CL data, and detect the cutting conditions such as the feed rate. The geometric simulator shows machining process and detects implicit cutting conditions such as depth of cuts and metal removal rate. The physical simulator estimates instantaneous cutting force and machining error. From these estimated results, the VMSim can detect the problematic NC blocks in which cutting force and/or machining error exceed the considerable limit. Furthermore, the VMSim can modify the problematic NC blocks by means of changing the feed rate so that the cutting force and the machining error can be maintained under under the limit value. As the case study, an NC program that makes cavity shape is modified successfully.