Composite Position??

[[Ma...]]

I'm seeking advice for how I may go about evaluating dimensions 68/72/74 correctly. I attached the relevant views of the drawing. I understand the function of a composite position when it comes to a bore pattern and how to evaluate in that case but not how I would apply this to a singular feature. I'm also curious if I'm generating datum -A- correctly. TIA for any suggestions or information you may provide.

BL325-1.png

[[Er...]]

I would get with someone who could say what the intent is of the dimensioning and how the part is used.
This is weird. So I am just throwing this out there.

Assuming ASME Y14.5
Applying 4.11.6.3 and 4.16.6 for the [BSC]
A "datum feature simulator" is to be used.
The intent seems to be -B- as a cylinder controls translation on two axis. It is then used to locate -A-
Then -A- is left for the rest. So four points making up -A- level, "clock" the part, and locate the last translation.
Applying 7.5.3
Assuming that the leader for 68/72/74 points to the centerline of multiple features as a GROUP.
68 Individual features associated with the centerline have a 0.018 tolerance as a GROUP using -A- and -B-.
72 The GROUP to themselves have a tolerance of 0.002 using -A-
74 Each individual feature has a tolerance of 0.010 using -A-

But I could be totally wrong :>

[[Ro...]]

My interpretation...

Datum -A- constrains 5 degrees of freedom, similar to a cone. Datum -B- constrains the final translational DOF, which is able to best fit and slide along the midplane of -A-.

I would create a simple base alignment to find the part, using -B- as the X-Y origin. This is just to satisfy the print orientation. Measure 4 planes for -A-. Create a Geometry Best Fit alignment from the 4 planes, allowing all DOF to best fit.

Then create a Best fit bore pattern with -B- using the Geometry Best Fit alignment. Allow -B- to best fit/translate along the midplane of -A- in the best fit dialogue.

Use the Best Fit Bore pattern as your alignment for the upper tier callout of the composite. Use the Geometry Best Fit of -A- for the second tier of the composite and the single segment callout.

[[Ma...]]

Thank you for the responses. The current set-up is very similar to Roberts suggestion outside of the best fit bore fit pattern for B. Erik, the leader line is pointing to the ID, I cropped a bit too much from the image. I'm going to try and get in touch with the quality department of our customer and figure out why we're having the discrepancies and will report back with my findings. Again, thank you for taking the time and being a sanity check.