find "highest" point on circle as datum

[pcdmisstudent]

Hey all
I know theres already a bunch of "high point circle" thread, but i couldnt find one that helps me.

Ill upload two snaps of the drawing for your ease:

So you see the basic dimension 6mm should be from the highest point of the circle/cylinder.
The cylinder has a very short arc and im using pcdmis 2011 and a tp200 touch probe ATM.

Could anyone help me fix this datum? Its just used as a teritary to lock one orgin.

edit: ok i found a way to get better results. Aligned to A (midplane in Y) and B (midplane in X) then just took a vector point at orgin and made that point the datum. seems to work fine.

[YGOLORTEM]

I cannot see the entire part (and I'm not asking you to show me) but from what I can see Datum-C- is a flat plane.

Sometimes BEST FIT alignments and or Iterative alignments are better for "not square" features. I, myself, prefer to use a series of iterative alignments tightening up the the point target tolerance on each new iterative alignment.

[vpt.se]

I agree with C looking like it should be a flat surface.