3D surface topography prediction in the five-axis milling of plexiglas and metal using cutters with non-uniform helix and pitch angles combining runout

Surface micro-morphology (SMM) determines the working performance of a key component. Because, for metals (e.g. Aerometal), SMM affects the capability of holding lubricating oil, the fitting accuracy, and the serving life, etc. And for non-metals (e.g. Plexiglas), SMM affects light transmission, weathering resistance and mechanical strength, and so on. One of the most important ways to obtain the desired surface is the 5-axis flank milling technology. In this process, cutters with variable helix and pitch angles are used commonly, and the runout is also general. These angles and runout have great effects on SMM. Therefore, to consider these factors, this paper introduces an accurate model to predict SMM. First, true trace-surfaces of cutter edges considering process parameters are built. Then, sample lines vertical to the tool path are constructed. Based on these, a model to compute points on SMM is proposed. Third, the modified Levenberg-Marquardt method is presented to solve SMM model with an innovative way to determine initial conditions. Subsequently, the SMM can be obtained. Then, effects of the cutter runout, pitch and helix angles on SMM are also studied and some important principles are found. Finally, some examples and experiments are conducted to prove the validity of the proposed method.