Coaxial holes

I have attached a call out below. What would be the best way to report this out. They are 2 cylinders in line about .250” long each with a 2” space in between. I’ve tried to
1. level and origin on one then report the TP. Of the other
2. 3D best fit both cylinders trans and rotate and report of both cylinders using worst end of axis.
3. using geo-tol by selecting both cylinders with no datum

all of these came up with different results. Which is the best way? Any of these 3 or maybe some different ways?

Should both holes be reported out or just the one? Because technically one becomes datum in way.

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Neil Challinor over 2 years ago

constadin has the correct approach. It is composite position of a pattern of holes. The upper segment controls the relationship of the whole pattern to the datums and the lower segment is the relationship of the features within the pattern to each other - essentially concentricity between the two holes.
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Neil Challinor over 2 years ago

constadin has the correct approach. It is composite position of a pattern of holes. The upper segment controls the relationship of the whole pattern to the datums and the lower segment is the relationship of the features within the pattern to each other - essentially concentricity between the two holes.
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Jay_Q over 2 years ago in reply to Neil Challinor

I went with the geo tol option. But am I correct that I select both holes for the lower portion of the composite and report it out showing both?
The customer says I should only be reporting one hole. But I don’t think you can do that with geo tol.

Also what would be the legacy equivalent of achieving this result?
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Neil Challinor over 2 years ago in reply to Neil Challinor

I'd need to see the real drawing to give a definitive answer but based on your sketch of the feature control frame you are doing it correctly by selecting both features. If you only select a single feature then there wouldn't be any pattern and the lower segment would not make sense. To satisfy this callout using legacy would be extremely difficult as you would need to create a weighted 3D best fit so as to be able to include MMB. Even if you omitted the MMB, I'm not sure how you would determine the unusable areas (see Mike Ruff's post - #7) and exclude them from the calculation.
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