Caliper Distance + X/Y/Z Locations not matching

[[Za...]]

Hello all, I'm having some issues getting these .940 /Y locations to come in by using a secondary alignment on the features (the 1/4-20 thread minor diameters) and reporting the X and Y locations from the dialogue box of the features.

However, if I use a caliper distance from minor diameter of the threads to the diameter of that middle bore, the results are within the allowed +/- .005". Why would the results vary that much between each method and how can I be sure I'm reporting the correct results?

As always, any help is appreciated!

Thanks,

Zach

Caliper Distance Results:
Results using Secondary alignment and reporting X/Y Locations (please ignore that the wrong box is checked):
The secondary alignment I'm using:
The portion of the print being used for reference:

[[Ma...]]

Mainly because of A1 nad A2 angles. With caliper distance you can choose middle, min or max. But min and max will work with diameter. If you use data from cylinder as 3d-line then you can report min and max from axis of that cylinder.

Also - only caliper distance uses alignments - so it is perpendicular to axis of choosen alignment

[[Za...]]

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Is there any way to report those X/Y locations as they appear in the caliper distance dialogue box? I have many similar parts that are coming through right now that have this same check and I'm trying to avoid having to do a caliper distance characteristic for each .940" check. I'd rather be able to set the feature to a secondary alignment and report the locations through that dialogue box if possible, but they keep checking out of tolerance when they are in fact not out of tolerance (verified with a height gage).

[[Ma...]]

What problem do you have with caliper distance usage?

Just to mention - don't use X origin from 1.996 cylinder - use plain instead.
You can choose max inscribed evaluation for threaded holes for better position calculation.

And report only Y and Z axis 😉

[[Za...]]

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I guess I don't have anything against the caliper distance except for that it's not displayed as a "location".

I couldn't get the holes to come in how they should, so I'm just going with the caliper distances to save time now. I really want to figure out why the numbers are a few thousandths different from one method to another though.

[[Ha...]]

I just wonder why you scan those as cylinder? if you measured it as circle, everything should work well

[[Ma...]]

As Hai Bui said - you can change it to circles or cut it in middle to get center point and report this as caliper, or with proper alignment you can report just as Y and Z characteristic.

[[Er...]]

Or you change the point of measurement from the features own coordinate system to what ever you like.

But a x/y/z position of a cylinder is kind of wierd, unless its perfectly perpendicular.