How do you calculate position with angled datums?

2 questions for measuring the 2x .5247 +.0007/-.0000 holes to datums D-A-B
*The holes are NOT inline with Datum -B-

#1 how does PC-DMIS calculate where the Datum origin is calculated from?

#2 how would you duplicate this manually with height gage and rock?

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brian.freeman over 7 years ago

I gather your datums are planes. If this is so then DMIS calculates from the center of the Plane, not the 'intersection' of the planes; like is stated in Y14.5 fig 4.4.

Look at where your FCF Trihedron is.
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brian.freeman over 7 years ago

I gather your datums are planes. If this is so then DMIS calculates from the center of the Plane, not the 'intersection' of the planes; like is stated in Y14.5 fig 4.4.

Look at where your FCF Trihedron is.
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BWIZZLE over 7 years ago in reply to brian.freeman

yes, all three datums are planes. That's what I was thinking that it was using the centroid of the plane and not the intersection. So million dollar question is why does PC-DMIS do it incorrectly per ASME Y14.5?
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