I have this rod that has a datum A cylinder and datum B is center drill. I can create the common datum for a runout tolerance but when I create the runout feature it won't let me because they're 2 different feature types. So I created a generic cylinder out of the cone then PC DMIS didn't like that one feature had surface data and the other one didn't. I then created a generic cylinder out of the measured cylinder and then it would let me make my runout FCF feature. Why can't I make the common datum out of 2 different features?
Because the features you are trying to use are not supported yet. Extract from the help
CommonDatums
A common datum refers to a datum identifier like A-B or A-AB-B. It has one or more hyphens that separate defined datum identifiers. PC-DMIS supports two types of commondatums:
Coaxial cylindrical surface. These may have different nominal sizes and/or size tolerances. You may measure them as either cylinder features or circle features.
Offset parallel planes
The workaround would be to measure -A- as a cylinder and then construct a cast cylinder from it, measure -B- as a cone and again create a cast cylinder from it and then reference the cast cylinders as datum A & B. You will then be able to create a common datum A-B that satisfies the geometric tolerance commands' current common datum rules. We are working on expanding support for more types of common datum definitions for future versions.
Because the features you are trying to use are not supported yet. Extract from the help
CommonDatums
A common datum refers to a datum identifier like A-B or A-AB-B. It has one or more hyphens that separate defined datum identifiers. PC-DMIS supports two types of commondatums:
Coaxial cylindrical surface. These may have different nominal sizes and/or size tolerances. You may measure them as either cylinder features or circle features.
Offset parallel planes
The workaround would be to measure -A- as a cylinder and then construct a cast cylinder from it, measure -B- as a cone and again create a cast cylinder from it and then reference the cast cylinders as datum A & B. You will then be able to create a common datum A-B that satisfies the geometric tolerance commands' current common datum rules. We are working on expanding support for more types of common datum definitions for future versions.
Hi everyone, I just thought I'd provide a sneak preview of what's coming in PC-DMIS 2023.1
We have significantly expanded support for different types of common datum. 2023.1 will support combinations up to five datum features or datum patterns and many more feature types as part of a common datum. This means that the case being discussed here (combination of a cone and a cylinder) will be supported. Please consider taking part in the 2023.1 technical preview when it goes live if you would like to learn more and try things out for yourself.
