● V-F sliding surfaces of X and Y axes, spindle head, top and bottom sides of cross rail bridges are scraped for extremely high geometric precision.
●Z axis is NC controlled and two types of control (Z axis as cutting feed and Z-axis as chopping cycle) are available.               
●As for Z axis chopping cycle, the ball screw drive has realized the high speed of 200 cycles/min (at 25 mm stroke). Even at this speed, the bottom dead center precision is 2μm (J300G, J4GDN, J6GCN, J7GAN).        
●In J3GEN, the linear motor is adopted to the Z axis (first practical application for machine tools). Z axis chopping cycle of 400 cycles/min (at 25 mm stroke), which was impossible for traditional models, has been realized to drastically reduce the process time of contouring cutting. 
●Low thermal expansion casting is adopted for the head material. Error due to heat displacement is extremely small