Cookbook Settings

[[Mi...]]

Looking at the cook book on Perp and Axial Run out. CB says with perp to run the shaft as a lsq cylinder and plane as outer tang.

In regards to Axial RO it says use LSQ on the plane and use a GN cylinder for the datum.

Will I get a major difference if I use 2 circles and recall those into a 3D line and do the call-outs from the lines as opposed to using the cylinders in both measurements above??

[[Ma...]]

You will get different result. Form of a cylinder is in play. In CB they are mentioning function check - so cylinder will probably fit into hole so there is why they are using GN.

[[Er...]]

A major difference? That will depend on the form of the features and where the part is probed. And what the tolerances are, etc.

From my experience recalling circle points into a cylinder will give different results than measuring as a cylinder. It's the geometry/vector difference between a circle and cylinder.

The differences in evaluation are suggested because the measurements essentially swap datums.

[[Ri...]]

I just love how you are suggested to turn on some serious Outlier Elimination when evaluating a form characteristic.

[[Ju...]]

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Reminds me of when we had some parts returned, because I had accidentally left location constraints on for features with a true position callout lol.
"Why are they returning these parts? The true position was PERFECT!" 🤣