Precision ball screw directly affect CNC machine tool positioning accuracy ball screw models, precision ball screw grease ball screw parameters, which lead error effects on the positioning accuracy of the machine the most obvious. 1/3 ~ 1/2 General set screw in the preliminary design of any 300mm stroke volume variation should be less than the target set position V300p positioning accuracy values ??to determine the accuracy of checking in at the end. Lead screw selection is generally based on the design goals of the highest rapid traverse speed vmax, the maximum speed nmax and motor and screw drive servo motor than i to determine. Generally based on the design of the ball screw rated dynamic load to determine the dimensions of the ball screw. Dynamic load rating refers to a group of the same size ball screw after running a million times, the ball screw (threaded surface or ball) 90% of the non-axial load fatigue stripping injury (pitting) time. Minimum axial load of rail friction under the table and workpiece role when calculating the maximum axial load of the machine is the maximum load of ball screw ball screw transmission power, it is the axial cutting forces in ball screw The friction between the rail and component (in this case the common rail friction caused by the table, the workpiece, the total weight of the jig and the cutting force of the three components in the direction perpendicular to the rail. Select screw mounting methods include screw support way and screw special bearing selection, ball bearing different ways have a great impact on the stiffness of the screw, rotary precision, critical speed, generally depending on the length, rotary precision, stiffness requirements and speed to select different screw Installation 1) ball screw nut and a support system to detect and repair gaps appear when CNC machine tools reverse error, positioning accuracy of instability, when crossing quadrant marks appear, the first to be detected screw system has no gaps. Detection methods are: using a dial indicator with the ball on the end of the screw in the center hole, measuring axial runout correction Ball screw, the other dial mobile measurement workbench. Reverse rotation of the screw, observing the two dial indicator reflects the values, confirm the fault location based on the value of different changes. Correction Ball, Korea and Taiwan transmission machinery, ball provided by the Dongguan City, South Korea Taiwan Transmission Machinery Co., Ltd. Dongguan City, South Korea Taiwan Transmission Machinery Co., Ltd. (www.dghantai.com) is an industry leader in Dongguan, Guangdong, machine tool accessories, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. In Korea and Taiwan transmission machinery leadership with the staff warmly welcome all inquiries negotiations, Korea and Taiwan to create a better future transmission machinery.