Make this make sense

[[Ca...]]

 

Position is different if I pick individual datums vs base alignment. They both should be the same? Also if I calculate position, it should not be 0.4073 ( 2√(0.0843²+0.0167²)

[[Ma...]]

I think you should have selected: Plane A, 3d Line1, Circle B - i don't want to use this type definition of an alignment. I rather use normal alignment, where is realy shown where is origin.

Unless you have not fully defined alignment.

[[Cl...]]

I think I remember seeing a post not long ago talking about the difference between

two alignments using the exact Datum's, as in this instance.

I thought it had something to do with Evaluation Method for Datum - 

LSQ Feature

Outer tangential feature

ISO 5459

[[Ca...]]

Is this a bug? https://imgur.com/GQz3TUi

[[Ma...]]

I would rather fill circle B as third datum.

[[Ca...]]

Print called position to A and B only. So lets say if print called to A only, do I still have to filled out and put in B and C?

[[Ma...]]

I would fill all three with same feature for only A.

Or do your research about values. Like intersectioned circle, there you will have really one point.

[[Ca...]]

This is more confusing than anything. If print called for position to AB and I can't just plug in A and B. Depending on combinations of base alignment and/or A and B, I get like four different results.

Edited August 22

[[Cl...]]

It would be interesting to see what the result would be if you created a secondary alignment with A&B and evaluated to that.

[[Ca...]]

The result is same as base alignment.

[[Ro...]]

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When there is a position callout that is not fully constrained, a sub alignment should not be used in the position characteristic's evaluation. If you look below the sub alignment's name you see (Base Alignment) which means any open slot gets automatically filled in by what was used in the base alignment, making it fully constrained. That's why you see the same result. Attached a Zeiss document explaining this.

If the print callout is only to -AB- then you must only enter datums -A- and -B- in the position characteristic. No need for the 3DLine.

Also, when you create your base alignment, the features are evaluated as LSQ. Which is what you want. It's the most stable, repeatable evaluation. When you enter your features in the position characteristic, they should be evaluated as Outer Tangential for Planes and Max Inscribe for ID's and Min Circumscribe for OD's. Hence why you would see the difference.

Align_vs_Datum_Ref_Frame.pdf

[[Jo...]]

If you do not define enough datums to fully constrain calypso will give nonsense numbers.  Datums consume all possible constraints as they are applied.  (If datum A was a sphere, datum B would constrain nothing!) 

In its defense, the new GDT engine in 2024 features will show you an exclamation point when left unrestrained and it is GREAT

[[To...]]

A sphere could not constrain any rotations though.

[[DW...]]

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 Source - Earth. 🤣

Edited August 27