A MODEL FOR THE PREDICTION OF SURFACE FLATNESS IN FACE MILLING

This paper presents a new model for the prediction of surface flatness errors in face milling. The model includes the effects of machining c onditions, elastic deformation of the cutler-spindle and workpiece-fix ture assemblies, static spindle axis tilt and axially inclined tool pa th. A new method called equivalent flexibility influence coefficient m ethod is used to compute the elastic deflection of the cutter-spindle and workpiece-fixture assembly at the points of cutting force applicat ion. Single insert and multi-insert face milling experiments are condu cted to evaluate the predictive ability of the surface flatness model. A comparison of the model predictions and measurements shows good agr eement. The influence of static spindle axis tilt on the surface flatn ess error is found to be very significant. it is shown that care needs to be exercised in comparing the model predictions based on elastic d eflection of the machining system and spindle axis tilt with the surfa ce flatness error measurements due to the fact that these measurements may be inflated by inclusion of the surface roughness.