The design of the rail system strives to maximize the contact area between the fixed component and the moving component. This not only improves the load carrying capacity of the system, but also the system can withstand the impact force generated by intermittent cutting or gravity cutting, spreading the force widely and expanding the bearing capacity. The area of force. In order to achieve this, the groove system has a variety of groove shapes, two representative ones, one called Gothic (pointed arch), the shape is a semicircular extension, the contact point is the apex; the other It is a circular arc and can play the same role. No matter which type of structure, there is only one purpose, and strive to contact more of the radius of the rolling steel ball with the guide rail (fixed component). The factor that determines the performance characteristics of the system is how the rolling elements come into contact with the rails, which is the key to the problem.