Constraints not allowing rooftop support to be parametric, what is wrong?

[Anonymous]

Here is my file of a rooftop support. I need the total height, the width, and the crossbar height parametric. I have all the parameters set and dimensioned but there are constraints in the way of letting it work. What is wrong? Thanks.

[barthbradley]

You got a lot of nested groups. Why? 

...there's a lot that needs to be corrected here.  I think the one piece of advice I could give you, would be to make each of the components its own family and then nest them into a Host Family where you can make them into a single parametric assembly.  

...I'll add that Nesting Groups in Groups is not good practice.  

https://knowledge.autodesk.com/support/revit-products/learn-explore/caas/CloudHelp/cloudhelp/2016/EN...

[Anonymous]

I think you helped me with an earlier problem with a crossover and you grouped stuff together and dimensioned and locked just one thing to the reference line to make it simply, thats all I was doing here. How do I make them all individual families and nest them into a host family?

[barthbradley]

Yes, I kind of remember that.  I think I may have suggested the Grouping as a workaround.  I never would have suggested nesting Groups.  Also, didn't I recommend nesting the components?   That's the way I'd go.  

I'll inspect your family again later. But you've definitely got several constraint issues to resolve. Be a whole lot easier to resolve if the components were nested.   

[Anonymous]

What makes a family nested? Just individual families loaded into one family together? Because that is what I did in the first place, but then just grouped those components to make it easier, but I guess I shouldn't have?

So can I just ungroup those components? 

If so, what then to resolve the constraints issue?

Thanks.

[barthbradley]

Yes, you have it right. Nested families are families that are loaded into another family (Host).  What you want to do is use Ref. Planes in your host, and pull all your Labeled dimensions to and from Ref. Planes. By labeled dimensions, I mean dimensions that are parameter driven.  All the Ref. Planes form the working skeleton of the Family.  Everything else that moves or flexes is aligned an locked to these Ref. Planes, and just follow along for the ride when the Ref. Plane moves.  For this reason, I usually set up the "skeleton' first and make sure it flexes correctly.  Once I got that down, it's just a matter of aligning and locking nested components to the Ref. Planes.  

And yes, don't group.  It's not necessary in this workflow.   Essentially, a nested family is a group.   But better.     

[Anonymous]

I'm sorry I still can't get it. There are still constraints. Can you take a look?

Thanks!

[barthbradley · Accepted solution]

Here's my re-imagining...

[Anonymous]

Once again, AMAZING!! Thank you! Can I ask how you got the right and left sides to look like one group but not be a group? Did you just copy and paste it into a new family and load that into it? 

[Anonymous]

Also, did you do something to the voids on the struts? It seems to be much better than my version.