Composite Profile Call-Out to Datum A Twice.

[stkenitz]

I have a part where datum A is a plane, oriented (0, 0, 1). There is a plane below datum A, but also oriented (0, 0, 1).

The plane below datum A has a composite profile call out as such;

| .060 | A |
| .030 | A |

Isn't this redundant? I am not understanding what this FCF is trying to dimension.

[brian.freeman]

Yes, redundant. I would 'kick it; back to the engineers and ask what hey really want?

[JacobCheverie]

Parallelism. The lower tier serves as a refinement of the upper tier. Are you sure that there are no other datums in the upper tier? If not, then you and Brian are correct in that it is redundant. I agree, send it back.

[Schlag]

Location and a form refinement ? I don't think its supported by the standard but I'm putting a dollar that's what the engineer is thinking ?

[brian.freeman]

Then he / she should have just put it as .030 A.

[Schlag]

You are loosing available tolerance that way . So why ?

[Mike Ruff]

This callout is legit as long as it is composite. The .060 controls orientation AND location. The lower tier controls only controls orientation (parallelism in this case) to .030.