1. Decide on the conditions of use
　　 According to the weight of the moving object, feed speed, operation mode, screw shaft speed, stroke, installation direction (horizontal or vertical), life time, positioning accuracy.
　　 2. Pre-select ball screw specifications
　　 Pre-selected ball screw accuracy grade (C3~C10), screw shaft diameter, pitch, and overall length.
　　 3. Confirm basic safety
　　(1) Allowable axial load, confirm that the axial load is within the allowable axial load value range of the screw shaft.
　　 (2) Allowable rotation speed, confirm that the rotation speed of the screw shaft is within its allowable rotation speed range.
　　(3) Life, calculate the life time of the screw shaft, and confirm that the required life time can be secured.
　　4. conduct research according to performance requirements
　　 In order to improve the positioning accuracy and responsiveness during control, the following confirmation is required.
　　(1) The rigidity of the screw shaft
　　(2) Life change caused by temperature