A method for the prediction of cutting force for 5-axis ball-end milling of workpieces with curved surfaces

Abstract

In existing researches, only the milling tests in the state of single-tooth engagement can be used to identify cutting force coefficients. So, when the average cutting force–based calibration is performed for a 4-fluted cutter, several slots must be machined and the cutting parameters must be properly selected to ensure single-tooth engagement. To reduce the consumed time of calibration tests, we present the new identification expressions of the cutting force coefficient for the 4-fluted ball-end mill based on the average cutting force obtained by the slotting tests with double-tooth engagement. Meanwhile, a three-orthogonal dexel–based model is presented to calculate the cutter-workpiece engagement. Also, the researches show that cutting element position and spindle speed have significant effects on cutting force coefficients; however, there is no research that has built a fitting model of cutting force coefficients simultaneously related to this two factors. To accurately predict cutting forces for different cutting conditions, the influences of these two factors on cutting force coefficients are studied. Then, a fitting model of the cutting force coefficient related to this two factors is presented. After, to verify the accuracy of the proposed method, milling tests are performed on both the rectangular workpiece and curved surface. The results show that the proposed model can predict the cutting force for different cutting parameters with the relative error less than 15%.