Reduction of machining errors by adjustment of feedrates in the ball-end milling process

Abstract

In the ball-end milling process, cutter deflection is one of the main causes of machining errors on free-form surfaces. A methodology which adjusts feedrates to avoid these machining errors has been developed. A model, which is represented by the cutter feed vector and the normal vector at the surface, is derived to predict these machining errors. This model is applied to the determination of the rational feedrates, which satisfy the machining tolerance to the full, and simultaneously prevent unwanted results. A series of down ball-end milling experiments are run in order to examine this surface error prediction model and to verify the ability of the rational feedrates. In these tests, it is shown that the predicted surface errors by the suggested model are in fairly good agreement with the measured data along the cutter path, and the rational feedrates effectively keep the surface errors on the surface in the range of the machining tolerance.