True positional call out

[LRRP_Ranger]

I have a feature control frame for true position of a hole back to datums A/B/C. This hole is not dimensioned from either of the A/B/C datums. It's x,y location (basic) is from another datum which is dimensioned from the A/B/C datums. My question is is the control frame a legitimate call out.

[Kelly_Bramble]

Welcome to EE!

For all practical purposes Basic dimensions are tolerance-less as the tolerance is contained within the Feature Control Frame. The location of the holes (and position tolerance boundary specified) can be determined by adding and subtracting the basic dimensions.

Though it is a good practice to directly associate the basic dimensions with the related datum's it is not required nor is it wrong to chaining the dimensions requiring addition and subtraction to determine the actual location relative the datum’s...

[LRRP_Ranger]

Thanks for the information.

God Bless