Alignment constraints of nested 'Family Type' parameters

[chughes]

I am building a door family that contains nested Generic Model door panels.  The panels are simple, with structured and named reference planes and with all geometry locked to the planes.  Each nested door panel option is built from the same starting model, so all planes and parameters are the same between all options.  The nested families are swapped out using the 'Family Type' parameter in the host family.  This gives me a nice, flexible starting family for projects that can be used to quickly get to the 'look' of 75% of our work, with minimal brain damage for my users.

However, locking more than one of the nested references to reference planes in the host family overconstrains when swapping the 'Family Type' parameter.  I am locking the center of the nested panel to the center of the hosted opening and locking the nested panel face reference to the face of the host wall.

I can lock a single reference without issue, but I need both to lock for the model to be reliable.  Are there inherent limits to locking nested families and swapping them using the Family Type parameter?  This is the first time I have tried this.  I am nerding out at the possibilities.  I just need to understand how to control the alignments.  Below is an example of the two alignment constraints and cause it to break.

[ToanDN]

You seem to be do everything right, except I would lock the reference plane of the nested panel to the reference plane of the wall face, not the wall face itself.

[barthbradley]

I've encountered this before. Can we look at your family?  Can you post it? 

[chughes]

Attached.  Thanks guys.

[ToanDN]

One panel is not constrained correctly.  revised file attached.

[chughes]

Yes, sorry, I should have noted that I was focused on the left panel to start. The right panel is only locked to the center plane and doesn’t error when changing the door type.

With the unaltered file, in the Type parameters, change the 'Door Panel' to the other model.  It should throw a constraint error on the left panel.

The right panel will not because it is only locked to the one reference plane.  But the panels need to be locked to both in order to resize accurately *and* move with the wall thickness.

Thanks.

[barthbradley · Accepted solution]

Align and lock x and y Origins of the nested families to the driving Ref. Planes in the Host.  

[chughes]

Blargh!  Its so close.  Revit, jeez.

Aligning and locking the X and Y origin works. Woot!  I thought I would be clever and redefine the origin by changing which axes 'Define Origin'.  That *doesnt* work with 2 locked alignments. Boooo!!  I guess it only wants to use the original origin axes.

Not the end of the world, just something to keep in mind when building the nested family.

Thanks for the help.

[Caed9]

I was struggling with this issue. I Strongly recommend not to set the nested family's origin reference planes as Strong or Weak. Instead use Center (Front/Back), Center (Left/Right), Right, Left, Bottom, Top, and Center (Elevation). Or just try changing them to see which works. For my case it gave me an error when the origins were Strong or Weak.