Nondiametric Composite FCF...

[[Ca...]]

I have a drawing with a set of through holes. They're controlled with nondiametric, composite FCF's. See attached image. I understand that the lower portion of the control frame is only really controlling orientation. My question is, how would you answer this? A standard perpendicularity characteristic doesn't let you specify X/Y angularity. My only real thought is a secondary alignment, then reporting the A1, A2 deviations. Thoughts?

(The bad graphic is the best I can do.)

Untitled.png

[[Br...]]

The lower segments only control orientation to the datum reference frame, but they still control the location in reference to the features within the pattern. The actual name of the lower segment of a composite position tolerance is the "Feature Relating Tolerance Zone Framework" or just FRTZ. So make sure not to neglect the feature to feature relationships here. You can use a Best fit within the position characteristic in calypso when using the Bolt pattern option. Here you can disconnect the translational relationship to the DRF in the bolt pattern as a whole.

[[Ca...]]

Thanks Brett,

Best Fit was something that was talked about here as well. As for the feature to feature relationship, they're actually labelled as "Individually" which I take to mean Separate Requirement. I neglected to mention that in my original post.

[[Br...]]

The lower segments are already separate requirements by default. You would actually need a note stating they should be part of the simultaneous requirement if you didn't want them to be a separate requirement. The "Individually" note would refer to repetitive patterns of features related to a repeated datum reference frame.