Multi-body part mating issues

Hi,

I am trying to model a composite part that has multiple aluminium and brass inserts within it as a single part with multiple bodies of varying density.

I start with the main body which I am treating as the composite part which has hollow voids where the inserts will locate. I then insert the part ( Aluminium/Brass insert), mate it in position (fully constrained as far as I'm aware) and then circular pattern it to create the multiple instances which I require. This works fine.

After I save and reopen the file and it rebuilds, the inserts are no longer located correctly. This is, I believe, only the case for the patterned bodies though, I think the root part/body stays in place.

The original bodies become 'not in context' which I'm not sure I fully understand...

Any suggestions as to what's causing this and how to overcome it?

I want to avoid modelling the whole thing as an assembly, but I want the external references in case the inserts change slightly (thread size, etc)

Any help aprreciated,

Regards.

Steve

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