Linear guides with high requirements for geometric accuracy, motion accuracy, and positioning accuracy should follow the following principles in design:
The principle of error compensation is to meet the following three requirements in order to achieve mutual error compensation in the guide rail system:
(1) Intermediate elastic links must be installed between the guide rails, such as plastic strips (sheets) or fluid films for rolling elements.
(2) There should be sufficient pre tension between the guide rails to compensate for contact errors.
(3) The manufacturing error of the guide rail should be less than the deformation of the intermediate elastic body (component).
The principle of non-interference in precision ensures that the various accuracies of the guide rail do not affect each other during manufacturing and use in order to achieve high precision. For example, the straightness of rectangular guide rails and the straightness of side guide rails do not affect each other during manufacturing; The variation of the lateral dimensions of the Ping-V guide rail combination guide rail will not affect the working accuracy of the guide rail.
In situations where the above-mentioned instruments are not available, operators can hold tools such as round bars or wrenches to resist the machine housing closest to the self-aligning ball bearing, and listen to the sound of the self-aligning ball shaft being carried and rotated by the tool with their ears against the tool. Of course, medical stethoscopes can also be used for modification.
A normal centering ball shaft should produce a uniform, smooth, and non irritating sound, while abnormal centering ball shaft should produce various intermittent, impactful, or jarring sounds. Firstly, one must get used to the normal rotation sound of the self-aligning ball shaft, and then be able to grasp and judge the abnormal rotation sound of the self-aligning ball shaft. Then, through the accumulation of practical experience, one can further analyze what kind of abnormal sound corresponds to what kind of abnormal phenomenon of the self-aligning ball bearing. There are many types of abnormal sounds from self-aligning ball bearings, which are difficult to describe and mainly rely on accumulated experience.
When designing guide rail pairs based on the principle of close dynamic and static friction coefficients, the dynamic and static friction coefficients of the guide rail contact surface should be as close as possible in order to achieve high repeatability and low-speed stability. Rolling guide rails, ordinary sliding guide rails with embedded plastic plates or plastic sheets, have low friction coefficients and close static and dynamic friction coefficients.

The principle of automatic fitting of guide rail pairs requires that the guide rail pairs have the characteristic of automatic fitting in order to achieve high precision. The horizontal guide rail can be attached by the weight of the moving components; Other guide rails must be attached with spring force or roller pressure to ensure proper fit.
The principle of full contact requires that the length of the fixed guide rail must ensure that the moving guide rail is in full contact with the fixed guide rail at the two extreme positions of the maximum travel (without exceeding the fixed guide rail), to ensure that the guide rail pair is always in full contact during the contact process.
The principle of compensating force deformation and thermal deformation is that when the guide rail and its supporting components are subjected to force or temperature changes, the design of the guide rail and its supporting components should strive to make them deform into the required shape. The crossbeam guide rail of the Longmen machine tool is made into a convex shape to compensate for the bending deformation caused by the weight of the spindle box (or tool holder).