I received an email from client asking for a little assistance with an air terminal family. Apparently the diagonal line they wanted to indicate that the terminal is a "return" wouldn't play along when the family changed size.
Recently I was in Houston and David Baldacchino (Do U Revit? blog) and I had a chance to hang out. He told me about a new (new to me) video capture tool called Jing Project by Techsmith (makers of my favorite screen capture tool SnagIT) that allows you to do screen capture to video or images as well as audio. Then you can easily post the video on Screencast. This post is as much a test as an example of troubleshooting a family.
The issue came down to this. Revit constrains elements orthogonally. The diagonal symbolic line is constrained to the reference planes, not the edges of the neck opening that they wanted it to "follow". The video describes the process of using the Automatic Sketch Dimensions (ASD's) that Revit applies when we do not explicitly add our own dimensions or lock padlocks, for example. The ASD's will do the job nicely as long as well "tell" them what is important to us.
Here's a link to the video: (embedded it is too big to view on the blogger screen)
Download it HERE. (3.75mb)