1) ball screw nut and a support system to detect and repair gaps appear when CNC machine tools reverse error, unstable positioning accuracy, SFK ball screw marks appear when crossing quadrant, the first to detect screw system there is no gap. Detection methods are: using a dial indicator with the ball on the end of the screw in the center hole SFT ball screw, lead screw measuring axial runout, the other dial mobile measurement workbench. Reverse rotation of the screw DFM ball screw, observing the two dial indicator reflects the values, confirm the fault location based on the value of different changes. 1. No preload or less without preload preload ball screw is placed perpendicular, nuts due to its own weight caused by the rotation of the decline; no preload screw be a considerable backlash exists, it can only Machine used for smaller operating resistance, but the main concern is less positioning accuracy requirements. Silver to determine the correct amount of preload on the different applications, and adjusted preload before shipment; so when the ball screw before you order, please really detailed operation of the equipment. 2. torsional displacement too (1) improper heat treatment, the hardened layer is too thin, the hardness of the material is too soft or uneven distribution of steel ball, standard hardness nut, screw, respectively HRC 62 ~ 66, HRC58 ~ 62, HRC 56 ~ 62 . (2) improper design: slender ratio (Slender ratio) ... and so much smaller than the rigid elongated screw higher than slender boundaries must be 60 or less than if the elongated screw will produce much weight drooping. DFT ball screw drive machinery _ _ Korea and Taiwan ball screw provided by the Dongguan City, Transmission Machinery Co., Korea and Taiwan. 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.