Dimensioning off a centerline

[QuestionDispenser]

Hello Everyone,

I have an old print dimensioned similar to the attached image with dimensions and tolerances per ASME Y14.5 (no rev called out). The tab feature is positioned using its centerline. Taking the dimensions to an edge case (moving edge B closest to the vertical centerline), I come up with what's shown in the box. However, now the true A-B centerline is below 19 and out of spec. This has me wondering, is my edge case not an acceptable part since the true A-B centerline is out of spec? Or is this drawing improperly dimensioned (if the centerline must always be the A-B bisector, then the drawing should be overconstrained by the .30 and .15 dimensions).

Thanks

[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1695328453/tips/New_Bitmap_Image_s665wj.bmp[/url]

 

[mk3223]

IMO, the angle of the centerline is the primary control dimension and should be fixed first, i.e. 20-deg +/- 1-deg. The length of AC is secondary control dimensions. And, the length of BC is the third dimension for reference only.