Assembly Constraints blown away

[RedCoat999]

I have a simple rigid assembly which is constrained and fine. Then one of the sub-assembly objects gets modified, perhaps a chamfer is added on a surface. Then in the top level assembly, whatever constraint was back to that surface gets blown away, it appears the reference name changes when that surface gets modified with the chamfer (as one simple example). How do I create the constraint correctly to this surface so that it will not get unrecognized when that surface is modified? Thank you

 

[catiavbmacro]

Hello, do you really need to connect to the surface? If you really need to, you can always make one plane whic will control your model and also that constraint in the assembly.

It's not recommended to make constraints using faces it can always change and you will that described situation.