Hole Pattern on face perpendicular to primary datum

[rkrz]

If I have a part (a cube for example) which has the primary 'A' datum on the bottom surface (B and C datums on faces perpendicular to it), and a hole pattern on one of the surfaces perpendicular to A. In a composite frame I would have the top to datums ABC, then would the FRTZF be only to A or need to be back to A and B (lets say B is the face of the bolt pattern).

In summary, how would I reference a hole pattern that is on a face perpendicular to the primary datum.

Thanks.

 

[pmarc]

It depends on what you need. If, in addition to controlling the spacing between the holes, you only care about perpendiculatrity of the holes in the group to A, use A only in the FRTZF. If you want the pattern to be also oriented to B, specify A|B.

 

[3DDave]

Using references that represent the way it interfaces with other parts is a good start. If the part is forced into position against a surface, include that surface in the feature control frame datums. The perpendicularity doesn't usually matter, but without a specific full assembly description making guesses about exceptions isn't helpful.