Static and dynamic models for predicting the effects of supports on machining flatness and roughness

This paper presents analytical static and dynamic models of a rigid workpiece held in a machining fixture in contact with locators and clamps (in a 3-2-1 scheme) and three supports (in three locating planes) influenced by machining forces and moments. The model is used to predict the effects of support parameters including the support position, rigidity and preload on improving machining accuracies. Milling and creep feed grinding experiments are performed to verify the model. The model can be used to develop present computer aided fixture design systems that consider only locators and clamps in a force analysis module.