Create analytical planes from an in-place model

[Anonymous]

Hi all! I've ran in to some problems and could really use a helping hand.

Is there any way to create analytical 'planes' (1. in picture) from an in-place model (3.)?

I want to design some complex components as a flexible family but still be able to analyse the structure in Robot/FEM. Or is there a better way to do this?

Thanks in advance!