To predict the milling force of spheric end mills in CNC milling process,the cutting tool was divided into many cutting elements,along its axis so that the milling forces would be the sum of all forces of all cutting elements participating in cutting.According to the empirical formula of dependence of tool milling force on cutting load and taking tool disalignment,force variation,and thermal deformation into account,the expression of instantaneous cutting thickness was derived on condition under the of thre...