Base Alignment Issue, I cant Replicate 2015 vs 2019.

[[Si...]]

Hi All,

Quick background on this issue. Our Supplier has 2015 Calypso and Articulating Head vs Our 2018 Calypso Vast XT Gold Fixed head. We have both been trying t correlate as best as possible. They use a steel fixture with the part Vertically standing vs our 3 point setup free standing (unconstrained) . They always have passing results where we have failures.
I received their Program last night, opened it up and the B.A. they have I am confused on how Calypso even calculated it. See attached hand sketch.

Its a complicated Casting but a square I feel would show what I am talking about. Supplier has the Block up Vertically with the 2 Circles on left side. They probe 4 points to make a Plane opposite Datum -A-. Then 3 Pts in Circle 1 & 2.

This is where I get confused... The Alignment setup is Plane 1* Spacial, 3 D Line Rotational, X Circle 1, Y Plane 1*, Z Circle 1.

How is that possible to have Plane one control the Spacial?? I try this exact alignment and Calypso " Unable to Calculate" .... Am I missing something?

Also would like to mention they do have a SECONDARY Alignment which is correct and is how I align the Part for its called out Zero on the Drawing.

SUpplier Align Sketch.pdf

[[Ow...]]

Silvio,
Aside from them using the wrong plane as Datum (they can’t access it because of the fixture?) I don’t see anything wrong with their alignment. GD&T might dictate differently but, generally a plane for spatial, the largest surface surrounding the features works best in defining how the part is tipped in 3D space relative to the CMM axis.

I’m not sure how your alignment would be different but, If I was going to guess what was causing the different results between the two CMM’s, I would say it’s because they are constraining (clamping) the part against the fixture. If datum A is not flat and they’re clamping against it in 4 places, they are taking any non-flatness or distortion out of the part/face and when you check it un-clamped, you see the distortion.

That doesn’t mean the way they’re checking (constrained) is wrong because, I’ve seen prints that specify a part be clamped/constrained to simulate how the part would look assembled to its mating part. It all depends on how the part and its features are expected to conform after or before it’s mating part.

[[Me...]]

I would check these directions. your clocking line should be z- if i am interpreting your drawing correctly.

[[Ma...]]

Yeah, there is nothing wrong with their alignment. I think Joseph is on to what is happening.

Mark