Runout agains bevel gear

[[Ed...]]

Hi everybody,
Need some advice and help 🙂
How would you, my friends, define this Datum A? It is pitch of bevel gear and and bevel gear is not machined!
At the moment I made 16 self centering points, recall them to circle. Did this in two different heights, so now I have 3D line and cone.
When I measure radial runout on three different heights against 3D line, the results are various at every height, but against the cone they are more similar.
Also I have opposite master part, so I checked everything with dial indicator and there I got another numbers 🙁
Any suggestions?

BR

Ekrānuzņēmums 2023-04-28 152443.jpg

[[Ma...]]

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I hate to see the bevel teeth used as a datum. The teeth do nothing to locate the part and gear classification always provides tolerances relative to an axis of rotation defined by datums other than the teeth, ideally the functional datums of the part.

If you must do this to comply with the drawing, you must recall your self-centering points into a cone and use this for the primary datum. Recalling the points into a circle can only give correct results if all the points are arranged to contact at the same height and radius of the actual cone.