1) positioning error is mainly related to 20 0.07. Because only the positioning error is considered, the influence factors of aperture φ 20 (+0.045/0), φ 60 (0/-0. 14) and 45 can be ignored (if these three factors are considered, the calculation will be relatively complicated, but

2) Calculate the maximum horizontal offset and vertical offset of φ 20 hole center. Assuming that the central coordinate of φ 20 hole is (0,0), then:

The coordinates of the limit points of the horizontal displacement of 20 0.07 are (-0.07,0) and (+0.07,0) respectively; The vector offset is: left shift-0.07; Move 0.07 to the right;

So the radius of the accumulated positioning error of φ 20 center, that is, coaxiality, is the sum of the square of 0.07+the square of 0.07, and then the root sign is opened.

?