Cumulative runout lower than runout?

[[Co...]]

Hello All,

I've been banging my head against this issue for a little while now and am hoping that someone here can help me out. I'm measuring a cylindrical part, the OD of the part is the primary datum and I'm measuring the runout of an ID cylinder back to the OD. The OD is 4 unconnected lands that I recalled feature points to make a cylinder and the ID is a cylinder feature that I'm measuring with two circle paths. I've then created two characteristics using the exact same datum and feature, one just radial runout and one cumulative radial runout. I'm assuming that cumulative radial runout is the same thing as total radial runout, and I can't figure out any situation in which total runout would be less than the runout of a feature. In this instance I'm getting less than half the value with cumulative runout that I am with runout. You can see what I mean in the attached images.

Can someone help me understand what's going on here?

cumulative radial runout.pngradial runout.png

[[Da...]]

Please check if you accidentally recalled your feature points into a cone instead of a cylinder.

[[Ow...]]

Quick reply here with no coffee. 🙄
Total runout is cumulative runout.
The difference between the two (runout vs cumulative) is that while circular runout controls a single cross-section at a time, total runout inspects the entire length of the cylindrical surface simultaneously to another cylinder.
I'm not in front of Calypso so I would have to check but, I don't think you can use to two cylinders in a single runout characteristic (?) , only a cylinder and a circular section?
If it does allow you to choose both, then maybe it is taking the amount of taper (difference between the size at the beginning and end) into the calculation?