PRECISION POCKETTING IN THE BALL END MILLING PROCESS

Many die/mold parts including sculptured surfaces are usually complete d by pocketting with ball end mill. Therefore the precision machining in pocketting is important. It has been noted that the tool deflection produced by the cutting force is a main cause of machining error in p ocketting. The instantaneous deflection is dependent upon the static s tiffness of tool and the instantaneous cutting force. In this study, t he stiffness of holder was obtained by experiment and the stiffness of cutter was analyzed by the discrete elements along cutter length. The instantaneous cutting force was obtained by using the iteration metho d with the linear interpolation of basic machining data. By predicting the tool deflection in pocketting, a method improving the machining a ccuracy is suggested.