Concentricity between circles or cylinders

[dennisgilpin]

The question I have is what is the difference between measuring the concentricity between 2 circles (measured as circles) of the same diameter or between 2 cylinders (measured as cylinders) of the same diameter? Both circles or cylinders are on the same axis about 100mm apart?

Thanks

[dph51]

Using cylinders might use the centroid of the cylinder.

But you realize that PCDMIS reports concenticity as POSITION, (as per ISO) and not opposing median points (as per Y14.5 ASME).

Good luck.

[dph51]

From the Help file

The Insert|Dimension|Concentricity menu option calculates the Concentricity of two circles or cylinders, cones, spheres. the second feature that is entered is always the datum feature and may be a line feature that represents an axis.

[vpt.se]

Coaxiality for cylinders, concentricity for circles.

[JEFMAN]

Coaxiality for cylinders, concentricity for circles.

+1 !

[keego]

I was taught to do conc between a circle and cylinder, with the cylinder being the datum. Regardless, concentricity with a CMM just outright sukks. Especially as the features get more distant from one another.