I have a bore that is Datum B. It has a perpendicularity callout to Datum A, which is a flat surface. So, I have to measure it as a cylinder. I have another bore that has a circular runout callout to AB. So do I have to measure B again as a circle? Because I would have to assign that as another datum to build the feature control frame. But if I just use B as a cylinder, then wouldn't it be measuring total runout and give me a different result than circular runout?
Now I'm more confused that ever. I measured the cylinder by first measuring 10 individual circles at different depths, then constructing a cylinder out of those 10 circles. I dimensioned the runout of the constructed cylinder as well as the runout of each circle. I thought the circular runout would be the worst individual circle and the total runout would the difference of the highest max and the lowest min. Except the total runout actually measures LOWER than any individual circle. Maybe I'm really not understanding it or I'm just not programming it correctly.
Now I'm more confused that ever. I measured the cylinder by first measuring 10 individual circles at different depths, then constructing a cylinder out of those 10 circles. I dimensioned the runout of the constructed cylinder as well as the runout of each circle. I thought the circular runout would be the worst individual circle and the total runout would the difference of the highest max and the lowest min. Except the total runout actually measures LOWER than any individual circle. Maybe I'm really not understanding it or I'm just not programming it correctly.
