Unexpected behaviour when capturing position within subassembly

[royshearer]

I am getting an unexpected outcome when editing positions of components in subassemblies:

I have a subassembly that I have copied 8 times, and arranged by moving and using capture position. Now I want to edit the positions of components within the subassembly. Normally when I edit the master subassembly, the changes do cascade through to all the copies, which is what I want. However when I move components within the subassembly and then choose capture position, the changes to not cascade to all copies. I suspect this is because there are other 'capture position' operations in the history after the one i edited, and these override the edits I made.

This is confusing to me because in other solid modellers I have used, the behaviour is that positions are not absolute in this way, but nested, ie. a components position is computed relative to its parent assembly and that assembly's position is determined as a whole relative to its parent and so on. It seems to me that component positions here are being determined absolute to the main assembly. I may be rationalising this wrong of course.

In any case, is there a way for me to edit positions of components in my master subassembly and have them cascade down to all the copies, with later, higher level, position edits still in place?

[jeff_strater · Accepted solution]

Here is a video that hopefully explains some of what you are seeing.  Sorry, the volume came out very low, so turn up your volume.  Also, Screencast for me was not working today, so I cannot embed the video - it is attached.  Again, sorry.

The executive summary is:  Positions of components in a sub-assembly can be driven from the top-level, or from the sub-assembly, and this may account for some of what you are seeing.  If what you are seeing is different, let me know.

[royshearer]

Thanks Jeff, that does confirm my suspicions. However, what was confusing me more was that in the initial arrangement of the subassemblies, I did not move any components individually, just the entire subassemblies. So it is still a little odd that the components' position is not still being driven by the subassembly.

I don't know if this is related, but I am not using referenced designs as in your example, but everything has been modelled in the one design file.

Your video throws up another question: Is there a way to undo the change in which assembly is driving a component's position? Eg. in your example, how can you get the yellow block on the right to conform back to its position in the subassembly? If you delete the capture position in the top assembly for that move, will that do it?

I don't think the answer will help in my case, but it would be useful for the future.