I need to dimension a perp between a plane and a cylinder. When dimensioning the perp, I get two very different results when I switch back and forth between PLANE to/from CYL.
1. Why are the results so different? (we are talking 0.0003 vs 0.0238).
2. Is there a best practice for dimensioning perps? To have the plane back to the CYL (having the cyl be the datum), -OR- the CYL back to the plane (having the plane be the datum)?
p.s. Yes I know to follow the drawing, I just need to explain to engineering what the CMM sees, and have a peace of mind.
If it is a short cylinder, then the cylindricity may cause problems with inspection/results due to the axis being slightly off and also compared to the overall size of the element (the size of the planes).
What is the length of this cylinder?
I have seen it happen on several parts over the years. But that would make sense because sometimes these parts are so "short" that the cylinder top and the cylinder bottom are </= 0.005 apart.
I have seen it happen on several parts over the years. But that would make sense because sometimes these parts are so "short" that the cylinder top and the cylinder bottom are </= 0.005 apart.