Abstract: In order to eliminate a delay in a driving system and a control system during sequential operation of various component parts, to thereby realize a high speed and easy multi-axis control, a work delivery and removing device (7), a grindstone retracting device (14) and a gauge retracting device (19) are driven by respective compact electric motors (15, 13, 18) through associated reduction gear units. A reference pulse generator (34) for sequencers for generating reference pulses is provided, which reference pulses are distributed by a pulse distributor (35) to various position change curve setting units (36A, 36B, 36C). The position change curve setting units (36A, 36B, 36C) are a so-called electronic cam and output in response to receipt of the corresponding reference pulses respective position commands representative of predetermined position change curves (a, b, c). Servo-controllers (37A, 37B, 37C) are used for controlling the electric motors (15, 13, 18) in response to these outputs.