Ball screw drives usually provide mechanical efficiency greater than 90, so their cost is often offset by low power requirements. The ball screw has increased load capacity, long life and predictable predictability on the screw. Repeatability and accuracy are measures of how close the motion system is to the command position, and are defined as the large error between the expected position and the actual position. Repeatability defines the ability of the system to return to position during an operation. Ball screw drives have colored (backlash depends on ball bearing diameter, but usually) and (precision ball screw is inch / foot, standard precision ball screw is. Accuracy is a common measure of ball screw accuracy. The 360 ° rotation distance of a single ball screw is referred to. The lead accuracy is measured as the allowable travel variation (actual position and theoretical position) per foot or 300 mm. Ball screw manufacturer Precise and accurate control of the whole traverse is provided. Backlash is the free movement between the nut and the screw. The best way is to keep the screw from moving, push and pull the ball nut axially and measure its movement with a dial indicator. Clearance can also be measured by placing a dial indicator on the ball nut in the system and driving it forward one inch and returning to the original position. The change is a rebound. Repeatability is only a quantitative value of ball screw clearance. The non preloaded ball nut has a partial clearance between the components, which means there is a clearance. There is no preload ball nut, so the clearance is eliminated and the stiffness is increased.