Framing Family Analytical Model

[Ampersand]

Hello everyone, my question is, is it possible to add Analytical Lines to my framing family?, I am modeling a customize truss using framing family but in my project only appears one analytical line, it would be useful to have the bottom chord and web analytical model too if possible. I'm using Revit 2014. Thanks and regards

[KateMorrical]

Truss family templates support additional analytical elements.

[Ampersand]

Hi Kate, thanks for your reply

Sure the Truss family template has the complete analytical model, in fact, for analytical model purposes I use a truss modeled from a truss family template, but the disadvantages of the standard truss family are:

- Only one section type (profile) along the chord
- Only one section for all web members
- Height is not very accurate so to get the desired overall height I have to substract the half of the chords depth from the desired overall height.

So, for that reasons (and others) I proceed to a customized truss-look-like framing family, but as I cannot (or dont know how) add analytical lines, what I do is to model (the analytical model) using standard truss family template based trusses, and once I completed my analytical mode, I delete thoses trusses and replace them for my customized framing truss.

Of course this is a double work and waste of time but is what is necessary.

Thanks and regards.

[KateMorrical]

Actually you can have as many sections as you like for the chords and webs, although it takes some manual labor. Once you load the truss in, just select the individual element--using Tab to get past the overall family--and change the type. You don't even have to unpin anything. (Chords do take a little pre-planning, but you can split the line in the family to generate separate elements in the model.)

Fiddling with the height is a little trickier. You can do some of it with adjusting the justification of your chords, but then it can throw off the web alignment... Mostly I do what you said and manually subtract the extra depth.

[kmarsh]

Hi Ampersand,

You're right. Unfortunately these are still limitations of the truss family though individual web members can be changed to different sizes after the truss is placed. There is, however, still a chance that the members will be reconfigured if the truss re-sizes. You can do some tricks with attaching to roofs to make the truss more height constrained though I also understand your statements.

In terms of the analytical model, the analytical projection lines were removed from the structural family editor a while back and though there have been many discussions about how to manage this issue there is still no solution. I don't like to promote the use of in-place models though an in-place model would allow you to add analytical model lines to the family definition; however, many analytical packages with links to Revit will not recognize analytical model lines from in-place families. How useful an in-place model would be will depend on your analytical package.

You could also consider using truss families for your analytical elements and just hiding them with a filter for your presentation views (no need to delete them. They can also be filtered out of schedules with a little creativity). Just some things to think about.

You could, if you wanted a more thorough workaround solution, create an add-in (or commission one) which locates your custom truss members and replaces them with structural framing before export. Although, analytical model connectivity would potentially be an issue, it would take some work for sure. However, if it can speed up your process and save you from doing double work maybe it's worth investigating...

Hope this helps,
-Ken