In most NC machining companies, operators decide the feedrate by experiences and subjective judgements. The objective of this study is to improve a precision and a production time for finish in the CNC Milling. To reduce the polishing time for the final product, the finish cut should meet the desired surface requirement. There are some errors in machining even if the part program is geometrically perfect and the workpiece is setup without any displacement error. Such errors can be called as contour errors that are mainly caused by NCK(Numerical Control Kernel) and servo delay. In this paper, the main issue is that NC code for finish is optimized by virtual machinining process.
This research uses the virtual machining which contains NCK and servo mechanism. The simulation produces the Error Map Table which shows contour errors accorging to a feed rate and an angle between two linear blocks. NCK is designed which is based on Fanuc-OM controller and the first order system is designed for a servo mechanism. On a basis of the Error map table a normal NC code is changed to a code withthe optimum feed rate. In order to test the performance of an optimized NC code, a workpiece is used to measure the contour accuracy.
