true position

[[Bl...]]

When reporting on a true position, is it better to separate datums within the feature or use a secondary alignment that you have already constructed and just select it in the feature?

[[To...]]

I think you mean to say characteristic instead of feature. In the True Position characteristic, it is ok to do whatever you want. However, if you want to meet ASME Y14.5, it's important to understand evaluations and constraints, both of which can be controlled in the individual datum callouts, i.e. Primary, Secondary and Tertiary. These properties can also be specified in the secondary alignments though I personally feel doing that in secondary alignments is more work. The benefit of using the datum callouts is that Calypso can be set up to do the evaluations/constraints automatically.

I totally get why people like to use secondary alignments. I usually find that these people are former PC-DMIS programmers 🤣 In all seriousness, as long as the results come out accurately and to your satisfaction, then it doesn't matter how you do it.

[[Bl...]]

thank you. And yes you are right, I was a PC-DMIS programmer in my previous life!