GD&T Position to a Centerline (wince 😬) Datum

[[Je...]]

Hello.  Suppose you were required to measure the position characteristic on this print.  The print uses the centerline as a Datum, which is a no-no.  However, it "appears" the intention is that a line constructed from the center of the two internal holes is Datum A.

Also:

1. There is no diameter symbol in the feature control frame, so no cylindrical tolerance zone is overtly specified.

2. The print does not contain basic dimensions

Question:  Does this position characteristic only control deviation in one axis, which is perpendicular to the Datum A line, or does it control deviation in two axis (presumably in rectangular tolerance zone due to no diameter symbol)?






Thoughts??

.

[[Th...]]

I would think it can only control the single perpendicular axis. There's nowhere along the line that acts as a point to define the horizontal, so you can't define a tolerance zone along that axis in reference to anything.

[[Ma...]]

That's such bad drawing that it can pop somewhere 🤣

Bad thing is, there is no definition of base A ( does it came from holes, outer radiuses, symmetry of sides ).
Since there is no besic dimensions I would argue there is two possible callouts: concentricity to holes or perpendicularity to face.

And one good point - rectangle tolerance zone is correct.
This drawing would make us send additional questions to customer, or send our corrected version.

[[Mi...]]

I'll be devil's advocate, it's a Plane, not a Line. Meaning 3D feature.

Because the line extends past the holes, you could say it's a Symmetry Plane from either edge of the part.... then you report a single axis position since that's about all you can really infer from that with no Basics to say where along the centerline the holes should be...but the intent is to keep the holes in line with the center of the part...