Can't constrain length of element in an array?

[Anonymous]

I'm trying to create a frame family for a window screen. When I array the mullion the constraints controlling it's length break. It's a nested family, which I thought would solve the problem. I know there's are plenty of posts on this. I've read a ton and am still lost as to why the constraints break inside an array?

The .rfa is attached.

Any other advice on how I'm building this family is also appreciated. Thank you,

[barthbradley · Accepted solution]

Your Nested THA-D-Frame-Straight-AL Family is built incorrectly for the Array. It should lengthen in ONE direction -- not two directions via an "EQ" constraint.  

[barthbradley · Accepted solution]

Actually, you need to drive the Nested Family's "Length" Parameter via a Parameter in the Host Family.  

For instance, the "Length" of the vertical arrayed mullions are equal to [Frame Height - Jamb Depth - Frame Face].  Understand?  

...do you know you can do all this quite effortlessly with Curtain Walls in the Project?  

...attached file shows what I mean by the comments about the "Length" of the vertical arrayed mullions. See "H" Parameter in Host.  

[Anonymous]

Much appreciate! 

For anyone else in my shoes - I'd tried all that and it still wasn't working until I changed the original (undeleteable) reference plane from Centre L/R to Left. Just changing the Defines Origin plane to a new Left reference plane didn't work.

We've used curtain wall for almost all our windows for years, but are not happy with how it schedules.