Surface profile decision, allow less accuarte clocking

[prdave00]

The attached drawing is similar to a part I have. I need to control the profile of a detente on a spherical part (think construction ball locator with a shoulder) tighter with respect to the center of the sphere (datum D) and the bottom of the shoulder (datum B) to control the surfaces "orientation" with respect to the sphere's equator. Not as accurate, is controlling the "clocking" of the detente with respect to a flat on the shoulder (datum C).

I have talked to my supplier about just dropping the tertiary datum C, but I don't want to add any ambiguity in the long term.

The drawing has a few options I've considered, but would appreciate some guidance. This is another situation where I think they're the same, but not 100% sure. I'm also not sure if a composite profile tolerance is appropriate / useful here.

 

[fsincox]

I do believe people will object to the way you have "hung" your profile tolerance off the dimension as you have shown. The the actual tolerance is on the surface and not the dimension.
If your shop can make the first tolerance "all day" then there is no need for more, if not, there is your answer (this logic is stated very well by the ISO, IMHO).
Lastly, I prefer complete reference frameworks and refinements of such as opposed to completely separate partial frameworks, like the last example conveys. I am not saying it is illegal but it is incomplete at best.

 

[SeasonLee]

The primary datum feature D is a sphere, it will constrain three degrees of freedom (3 translations), the secondary datum feature B is a plane which will constrain two rotations DOF and the tertiary datum feature C constrains the last rotation DOF.

From your post sketch, we understand that there is a certain orientation requirement on the détente, you cannot drop the tertiary datum C from the FCF, otherwise the detente could be anywhere around the sphere’s equator as long as they keep the basic dimension 1 and .438. So, if you delete the tertiary datum feature C from the FCF, you will loss the control on the last rotation DOF.

SeasonLee