An Improved Method for Cutting Force and Surface Error Prediction in Flexible End Milling Systems

Abstract
As more emphasis is placed on quality and productivity in manufacturing, it becomes necessary to develop models that more accurately describe the performance of machining processes. An improved model for the prediction of the cutting force system and surface error in end milling has been developed and has been implemented on the computer. This enhanced model takes into account the effect of system deflections on the chip load, and solves for the chip load that balances the cutting forces and the resulting system deflections. Such a model allows for the evaluation of cuts in which deflections significantly effect the chip load. The flexible system model predictions of forces and surface error are compared against both measured and rigid system model-predicted values associated with the machining conditions for experiments performed on the 390 casting aluminum alloy. It is shown that the enhanced chip load model gives predictions of both cutting force signatures and surface error profiles that are significantly better than the rigid system chip load model developed previously. The fact that system deflections temper the effects of runout, and reduce both peak cutting force and maximum surface error is demonstrated and discussed.