XactMeasure versus GeoTol accuracy- comparative study of results

I would need you to send me a copy of the program (.prg & .cad files) to confirm but I do not expect there to be large discrepancies between 2018 & 2023.2 - providing everything has been programmed correctly.  By that I mean, THEO values matching the CAD nominals for all features, a fully constrained alignment BEFORE measuring anything that gets reported later and no partially constrained alignments mid-program (this breaks the alignment chain and can lead to strange behaviour), datums referenced at MMB/LMB must have been previously dimensioned - see "Determining the Size of the Material Boundary" on the following help page: How PC-DMIS Solves and Uses Datums

Good Morning Neil,

Neil Challinor said:

By that I mean, THEO values matching the CAD nominals for all features

The CAD is reference only so for every feature I have to run a location first and adjust nominals to print, then run the GeoTol.

Neil Challinor said:

a fully constrained alignment BEFORE measuring anything that gets reported late

I may get their Engineers to correct this at least but most features are ABC with A plane defined by flatness, B is position MMC from A-C MMB, and C has no geometric definition.  To follow print as it currently stands, I've already lost and would like to find out if XactMeasure can do this as GeoTol is not happy.  I don't get a Datum does not constrain error like some FCFs from another customer that doesn't understand common datums (A | B-C | B), but I know it is treating datums as 0.  Further D and E datums have no constraints other than linear dimensions.  Their Engineers don't understand the necessities of PCDmis but I would have figured their Quality Lab would have chimed in by now.

Good Morning Neil,

Neil Challinor said:

By that I mean, THEO values matching the CAD nominals for all features

The CAD is reference only so for every feature I have to run a location first and adjust nominals to print, then run the GeoTol.

Neil Challinor said:

a fully constrained alignment BEFORE measuring anything that gets reported late

I may get their Engineers to correct this at least but most features are ABC with A plane defined by flatness, B is position MMC from A-C MMB, and C has no geometric definition.  To follow print as it currently stands, I've already lost and would like to find out if XactMeasure can do this as GeoTol is not happy.  I don't get a Datum does not constrain error like some FCFs from another customer that doesn't understand common datums (A | B-C | B), but I know it is treating datums as 0.  Further D and E datums have no constraints other than linear dimensions.  Their Engineers don't understand the necessities of PCDmis but I would have figured their Quality Lab would have chimed in by now.

DR LokiZ said:

Their Engineers don't understand the necessities of PCDmis but I would have figured their Quality Lab would have chimed in by now.

It's not a requirement that's specific to PC-DMIS, it's how material boundaries on datums are supposed to be calculated according to the standards.  The following extract from the help file details where you can find the information in either ISO or ASME. 

Thank you.  That was the section I was looking for.  I need ASME Y14.5-2009 § 4.9 for them but the bridge was easily made.  I knew it was there in -1982 and -1994 (weakly) but the intent was there.