Please suggest tolerance scheme.

[JV1]

Hello everyone,

I have the following situation and I would appreciate if someone can suggest a tolerancing scheme for the following group of holes: I have three holes. The circular outside boundary of the part is not important. The three holes are inline. The top and bottom holes have a tight diameter tolerance. The center hole does not. The center hole is located midway between the top and bottom holes. The center hole can drift a lot perpendicularly from the plane formed by the top and bottom holes. However the position of the center hole to the midpoint must be tight (see attached sketch).

I am thinking of making the one of the sides of the part where the holes are datum A. Then, making the top and bottom holes a single datum. So, I apply a position tolerance to these two holes relative to datum A and make them datum B. How do I use TP or symmetry to dimension the center hole and assign the requirement described above?

Thank you.

jv

 

[powerhound]

See fig 5.41 on p. 139 in the standard. This is how you position bidirectionally.

Powerhound, GDTP T-0419
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[desertfox]

Hi JV1

I agree with powerhound.


desertfox