The design and calculation of the position comprehensive inspection tool must balance two aspects of the problem. First of all, it must meet the inspection requirements, and in addition, it must meet the processing (accuracy, capacity) requirements. Generally, position detection is suitable for the largest entity; the position tolerance zone is cylindrical Φa; pin type detection is commonly used. The size of the inspection pin should be equal to the minimum size of the hole to be measured minus the position tolerance (diameter); the fit between the inspection pin and the bottom plate hole (bushing) is generally H7/h6. It can be verified with CAD drawing method. At this time, the outer diameter and envelope range of the inspection pin are exactly the requirements of the position tolerance. The coordinate dimensional accuracy (tolerance) of the bottom plate hole depends on the position requirements of the hole to be inspected. The measured hole is an important hole, and the general dimensional coordinate tolerance is ±0.015; the measured hole is a threaded hole, which can be appropriately reduced. The pin inspection matches H7/h6, and the dimensional coordinate tolerance is ±0.015, etc., which is selected to meet the highest possible processing accuracy (can be achieved). The above design ideas are the current methods of weighing inspection requirements and manufacturing capabilities. It is inevitable that "detection contradictions" will occur. It's the same as plugging a manhole. For reference.