XY Origin 3D line

[[Pa...]]

I'm measuring high speed rotor hub in jet engine. It is comprised of concentric cylinders, cones and torus' along the rotating axis of the part. Both program's spatial alignment is from one end-plane (FWD or AFT) of the part, but XY origin is located with a stepped cylinder constructed from opposite-end concentric datum cylinders, thus making my XY origin an end-on view of a 3D line.
The program was written off site and though that strategy makes sense, I'm now questioning if it is best; the stepped cylinder origin produces different results depending on which end plane is used for spatial alignment and though they should be reconcilable with each other, I have been unable to do so. Is above strategy an invitation to chase your tail?
Possible better strategy: place XY origin using a circle datum located halfway between the two end planes. I realize without the print it's impossible to answer this question definitively; my question is more general in nature: What is the best strategy for inspection of spin balanced high speed rotating parts?
Machine is Prismo with dynamic XR head and rotating table.

[[Ri...]]

Is the RT being used for this measurement plan?

[[Pa...]]

Richard
Yes rotary active for most (but not all) of the circles/cylinders up and down the part.
And I’ve wondered about that—probably better to use the rotary table for all of the runout features?
PaulS

[[Me...]]

I might be missing something and be way off, but why not use the rotational axis of the part as your spatial since the axis would seem to be the main function of the part/assembly?

[[Ri...]]

The program was written off site. Was it written with a routine for determining RT axis along with Part axis? Calypso must know the delta of those two axis or it can't possibly measure the part correctly.

[[Pa...]]

Sorry about delay in responding, I could not log in to the site for a few day. yes it was written with RT routine. When you say "Was it written with a routine for determining RT axis along with Part axis?", how would I be able to determine that? And if it didn't know the RT axis, how could Calypso give results?

[[Ri...]]

I'm sorry, I should have been more specific. There is a canned routine that comes with Calypso that can determine the RT axis. Some people use this and the setting "Use existing RT axis" for their part programs. For more tightly toleranced parts, it is recommended you use a routine within the part program that will determine the RT axis for each specific workpiece. This method will give you the most precision.