The C Axis interpolation issue of turning center has studied in this paper. The numerical control lathe, in general, can only carry out X and Z axes interpolation.It would be possessed the capabilities of performing multiple technology machining in one installation and improving the adaptive scope of technology greatly, provided that the lathe has the ability of C Axis interpolation. Several kinds of C Axis interpolation formulas have been derived in this paper. These interpolation formulas have been...