Abstract
This paper deals with influence of cutting force on machining accuracy and improving method of the accuracy in corner cut by end mill. Errors by corner cut are extremely greater than that of steady state cutting. When a cutter radius is equal to a radius of curvature of the corner, maximum machining error becomes 13 to 22 times as large as that of steady state cutting. Describing the position of maximum error by rotating angle φ from start point of corner cut, the position by the angle is φ=10° in down milling and φ=0°in up milling. And also cutting forces in corner cut are measured, and machining accuracy is analysed by a simple error generating model that depends upon cutting force vector and resulting stiffness of machine-tool-workpiece system. Calculated values or shape errors are almost coincident with that of experimental values. To improve machining accuracy, plunge and twice looped path cutting are recommended. But under the experimental conditions, difference of accuracy between steady state cutting and corner cut is smaller by diameter 17 mm in down milling and 14 mm in up milling.
