Hole position calculation interpretation

[[Ca...]]

The hole measurement on feature circle20 x-axis is different than when it's being evaluated for position.

I can height gauge it on surface plate and get similar value to 46.32 but there is no way for me to replicate 46.52.

 

Edited March 6

[[Ma...]]

If you are comparing actuals, don't forget to make correct evaluation of alignment.

Datums have to be tangential element and as i saw at Inspect also perpendicular.
You have probably made evaluation as Geometry instead of ISO/ASME

[[Ca...]]

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How can I toggle between the two? This is the setting I'm using for evaluation

[[Pa...]]

Remember that the primary datum in every single case sets the orientation of the coordinate system and therefore all tolerance zones. The X value in the feature is the location of the feature origin on the X axis in whatever alignment you're using.

The x value in the position is measured parallel (or perpendicular, or at some specified basic angle, I can't tell) to the primary datum, not your alignment.  It looks like that datum might be a derived centerplane which could make it virtually impossible to orient correctly on a surface plate.

I'd use a CMM for this 😁

[[Ja...]]

Filters and outliers also play a part. If you're just using the Calypso defaults, then the raw data in the feature isn't getting filtered, and the characteristic is getting a random preset value. The majority of the time, proper filtering often doesn't make a big difference however the more form error there is in a feature, the bigger the impact. I've personally seen it make as much as 0.018+" (0.457mm) difference, although most of the time it's somewhere between 0 - 0.0015" (0 - 0.038mm).