True Position of holes, without Diameter symbol in Control Box??

let me lay this out for you guys and gals the best I can:

I have Datum A wich is a inside Circle recessed into the top of the part. We will call this "Datum A"

I have another recessed circle on the bottom of the part. We will call this "Hole"

"Hole" has a dimension callout that reads as follows: Dia. 7.06"
[T.P./.010/A] Notice there's no Dia. Symbol in the Cntrl Frame

I have never seen this callout before without the Dia. Symbol in the control frame when in reference to a datum that is a circle or cylinder, have you?

If I run this with both features as Circles, I get a measurment of 0 (ZERO)

If I run this with both features as Cylinders, I get some actual numbers, but I don't know if they are correct.

If I run this with Datum A as a Cylinder and Hole as a Circle, I get 0(ZERO)

I am confused as to which way i am supposed to do this. Is the callout on the drawing messed up, or am I giving Pcdemon incorrect features to calc this dimension?

Any help would be greatly appreciated.

Sam

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REDWINGJ over 12 years ago

Is the Ø7.06 the same axis as Datum_A? If it is it's possible that there would be no deviation and therefore the measured would be zero. Probing it as a cylinder is giving you the bestfit of the cylinder which has at minimum 2 levels. The difference between the levels puts the position of the Ø7.06 feature in a different location than just using a simple auto circle and you would see different deviation. The drafter could have just missed it on the drawing but either way they are asking for the position of that feature. For me I would want to know the function of the feature to decide if I wanted to probe it as a circle or a cylinder. Either way works if it's in tolerance. I would think if the cylinder were important they would have asked for runout or cylindricity.
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REDWINGJ over 12 years ago

Is the Ø7.06 the same axis as Datum_A? If it is it's possible that there would be no deviation and therefore the measured would be zero. Probing it as a cylinder is giving you the bestfit of the cylinder which has at minimum 2 levels. The difference between the levels puts the position of the Ø7.06 feature in a different location than just using a simple auto circle and you would see different deviation. The drafter could have just missed it on the drawing but either way they are asking for the position of that feature. For me I would want to know the function of the feature to decide if I wanted to probe it as a circle or a cylinder. Either way works if it's in tolerance. I would think if the cylinder were important they would have asked for runout or cylindricity.
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