Abstract
This paper deals with the geometric error of bottom surface in end milling that depends upon the relative displacements of an end mill to a work. The results are as follows. (1) It is shown that the presented procedures are able to calculate shape errors of bottom surface machined by 4 edged square end mill. (2) Errors of bottom surface exist negative (negative means over cut) in both up and down milling. (3) The results of this analysis are almost coincident to the experimental values in the condition of 5 mm radial depth of cut. (4) In case of 10 mm radial depth of cut, both shape of errors only show a similar tendency. It is considered that inclination angles at end edge become 1.7 to 1.8 times larger than calculated values in end milling. (5) Under the experimental conditions, a returned edge cuts again about one half of bottom surface during each quarter of a revolution in down milling, but this phenomena do not occur in up milling.
