Creating ceiling element Family issue

[jim.murphy]

I'm new with Revit modeling & i'm trying to create an adjustable U-Shaped ceiling pocket structure that will cut thru the ceiling.   I've successfully built the model, and i've been able to get it to cut thru the ceiling using the "opening" tool.  However when back into project space, when i change the length of the pocket the opening does not adjust with it.

How do I get the opening to adjust with the pocket, or is there another tool i can use to allow the pocket to cut thru the ceiling and adjust with the pocket.

[ToanDN]

You need to reference the dimensions of the opening and the "pocket" in your family to the same parameters. Upload your family.

[jim.murphy]

I figured that, but i can't find where that happens.  

I drew the "opening-cut" but i'm not seeing where I can add the opening lenght to any parameters.  

Could you guide me to where this is?

[ToanDN]

See the screencast for building a ceiling hosted family that cut a rectangular opening (L x W) with an object offset some distance from the opening.  Very simple just to show you how to create dimension parameters in a family.  You can also do a search on YouTube for more detailed instructional videos.

[jim.murphy]

So i see that the opening-cut is fixed to the Type size.  Is it possible to make the opening-cut an instance and tied to the lenght of my 3D extrusion pocket?

[ToanDN]

Certainly. The example only demonstrates a method. You can set your equipment dims as dominant parameters and link the opening cut dims to them. Parameters can be set to Type or Instance, totally up to you.