The length of a family model's instance parameter is not matching a parallel line's length

[jeremiah.hawlader]

I made a family model of an I-beam that I'm trying to align onto a roof's parapet at a 45 degree angle. The parameter's length matches my reference line's length up to this point. However, when I add 45 degree void on 1 or both ends (to align both ends to the parapet), I lose 9/16" on the cut end(s). When I remove the void it returns that end to it's actual length. How do I fix this?

[RDAOU · Accepted solution]

@jeremiah.hawlader 

You are cutting part of it...If you are using the right category and modeled it properly, you should be able to schedule both the Length and the cut length

See GIF below - Cutting a Structural Framing using a reference plane

[jeremiah.hawlader]

Thank you! Learned something new.