What are limiting factors in a motion system when it comes to precision and accuracy?
Rockford: A number of factors can limit the axial accuracy of a ball screw. Many designers confuse linear accuracy and repeatability. Because of backlash, inadequate preloading of the ballnut can cause positioning inaccuracies that many times are blamed on lead accuracy. Other factors can affect lead accuracy, such as excessive friction from inadequate lubrication and ambient or built-up heat from thermal expansion. Some manufacturers account for this by including ports in the ballnut and hollow screws through which coolant can be pumped to negate thermal expansion. Kerk Motion: Scale and speed are big challenges: scale because of the need for fine resolution of position and the space to start, stop, and confirm, and speed because the laws of physics constantly work against changing the motion. Changing aspect ratios and shapes helps create space. Reducing mass cuts inertia and improves response time. Eliminating components opens up space, cuts mass, and decreases the tolerance stack.
