Multi-level assemblies with motion

[gobrewcrew95]

Alright, what you need to do is make sure that everything that needs to be constrained is constrained first. Once that is accomplished, you can right click on all of you sub-assemblies and make the option "flexible" checked. Also, if an assembly is grounded, it will not be able to move.

P.S. Inventor is also very finicky, so it might not always work out the way you want it too...