Surface shape prediction in high speed milling

Chatter is one of the main causes affecting the surface quality of machined parts. Since it occurs when a machining process is unstable, it is important to select process parameters that promote stability. However, this condition alone is not sufficient to ensure good surface shape because the dynamics of the machining system as a whole also affects the resulting surface. Thus, even in the absence of chatter, significant movement of the tool or the part may occur causing surface defects. This effect is significant in high speed milling. In order to select optimal machining parameters, a computationally efficient simulator has been developed based on a novel machined surface generation model capable of accurate and reliable prediction of the surface shape. The programme written in MATLAB^® predicts the surface shape from which surface finish, waviness, form and position parameters can be determined. A test bench consisting of a relatively low frequency second order dynamic mode is used to hold a test sample. The results obtained on a machining centre show that the predictions favourably compare with experimental results.