At times, I'll been working in a larger assembly and I'll have a sub-assembly as a working part. I assume that's fairly common. While working in that sub-assembly, I've tried to add new components and I noticed that I was not able to reference any features that were outside of that working part /sub-assembly.
Is there a setting or something that can be done to work around that? It would be nice if I could at least initially place a component by referencing those external features and then set final constraints to just features within the sub-assembly that I'm working in. Does that make sense?
My "work around" now is to have the top level active, place the parts and then drag them down into the sub-assembly. At that point, I make the sub-assembly the working part and then add the constraints.
It would also be helpful if I could have the sub-assembly the working part and have the option of adding components and referencing the features that are external to the sub-assembly. It can be useful to utilize external references.
I started thinking about this more after doing some NX tutorials. I did a tutorial for "Representation in the subassembly" and there was this statement: Note that the user interface does not currently provide any assistance in selecting just external faces, so this is a fairly labor-intensive operation, unless you can remove a lot of internal components from the display.
I then was doing a tutorial for "Wrap Assembly and Linked Exterior feature" and was doing the exercise for "Extract the exterior faces of an assembly". I had just done the previous tutorial for the representations so I was surprised to see these steps:
1.Choose Menu→Assemblies→Advanced→Linked Exterior.
2.In the Linked Exterior dialog box, with Candidate Bodies selected, click Select All.
3.Click Exterior Faces .
It looks like there's a filter for external faces. From that statement and also from what I've experienced adding components in assemblies, it looks like NX is just limited in what it can reference. Is that true?
Yes, I think I tried several times. I think it only gave the option of in working part. It did not give the option from within the entire assembly. I've run into this at different times, and tried the same thing.
If you are trying to use the 'Constrain' placement option while adding components, by default, you may only constrain onto children of the sub-assembly work part. If you want to constrain onto objects of components from other branches of the assembly then you need to turn on the 'Interpart Copy' option found within 'Assembly Preferences Assembly Positioning'.
With that setting on, then all faces/edges/datum in the assembly will be available for selection. However, when you do this a WAVE linked object of the face, edge, datum. etc. will be created in the work part. You need to use this with care as creating WAVE links accross assembly branches is not a recommended practice.