CNC lathe is also by the headstock, knife holder, feed transmission system, bed, hydraulic system, cooling system, lubrication system and other components, but the CNC lathe feed system and horizontal lathe feed system exists in the structure The essential difference. Horizontal lathe spindle movement through the rack, feed box, slide box reached the turret, to achieve vertical and horizontal feed movement. The CNC lathe is a servo motor, the ball screw to the skateboard and knife holder, to achieve z (vertical) and vertical (horizontal) feed movement. CNC lathes also have a variety of thread function, spindle rotation and tool movement between the movement through the CNC system to control. A pulse encoder is installed in the CNC lathe spindle box, and the movement of the spindle is transmitted to the pulse encoder through the synchronous toothed belt 1 1. When the spindle rotates, the pulse encoder sends a detection pulse signal to the numerical control system to make the rotation of the spindle motor and the cutting feed of the tool holder keep the movement relation required by the machining thread, that is, the spindle rotates one revolution when machining the thread, z move the workpiece a lead.