Dimensioning Question

Do you have an analogue scanning probe or touch trigger?  The easiest way to do this is with a scanning probe.  You can scan the tooth profile, starting at one side near the OD, going down the flank, into the root and back then up the other flank to the OD again.  You can then construct a circle at scan minimum: PC-DMIS Help Center - 2023.1 (hexagonmi.com).  You would need to work out what diameter circle you would need so that it contacted on the flanks rather than the tip or root .  If you've only got a touch trigger probe, you should still be able to use the scan minimum method, you would just need to take a series of vector points along each flank and combine them into a constructed set (make sure the density of the points is sufficient - see the rules on the help page I linked to).

A for the alignment, it depends on whether datum C is supposed to be centred on the specific, single tooth shown or if it's supposed to be a best fit of all tooth centres.  Also, what are the other datums (primary & secondary)?

Confused on why you don't have clocking, on the very limited drawing snip looks pretty clear that datum "C" would clock that part, and datum C should be between the teeth that's 15° from the indicated pad?

Thank you for your input Neil ! I am using a cmm with scanning capabilities and I will give this a shot and see if I can get it to work.

The C datum should be center line of tooth space and A is a OD and B is a flange. Gearing is all new to me so I didn't consider scanning the flanks.

Again, thank you for your input..it is much appreciated!

Yes, you are correct! The C datum would clock the part. I just never considered scanning the flanks for some reason. Thank you for your input as well!