3D Best-Fit Base Alignment

[[Do...]]

Can someone please provide an explanation of, or reference documentation for, the correct procedure to create a 3D Best‑Fit Base Alignment using XYZ coordinate data collected from tooling balls on a fixture?

Specifically, I am looking to understand the recommended steps, assumptions, and alignment methodology used to establish a stable and repeatable alignment from discrete tooling ball coordinate data, including any best practices related to datum selection, constraint application, and evaluation of alignment quality.

Any guidance, examples, or standard work that outlines this process would be greatly appreciated.

[[Ri...]]

I guess I'd have to see the drawing and the intent. 

I haven't measured too many fixtures with tooling balls, but of all the ones I've seen while there are tooling balls, they are still broken down to a 3-2-1 alignment. 

In all of my years I've only ever used a 3d best fit alignment once, and that was on a part that was just essentially a free-form blob. 

I think the most use cases for it is in the medical world (mainly orthopedic implants). 

Either way - to use it for tooling balls it should just be rather straightforward. Load the cad model - Created a new base Alignment (3d Best Fit Method) - select your tooling balls - ensure that the nominals are correct - turn on a Loop (probably minimum of 5x with a break condition). 

For measurement of tooling balls, unless there is some crazy requirement or concern, I would just measure the spheres with the Sphere Macro (looks like the Geometry Qualification). If you want to scan them, you can, but most of the time it is unnecessary. 

[[Je...]]

Hey

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I'm curious... what's the overall aim of this project?  Sounds interesting.  Is there a reason for best-fitting based on the origin of a tooling ball?  I assume there is, but before commenting on the process, it would help to hear the end goal.