Modeling Our Custom Hollow Core Planks

[Anonymous]

All,

My company is in the process of switching from a 2D AutoCAD 2013 Mech. to 3D BIM modeling with Revit 2014.  We are a precast firm that makes hollow core in 8", 10". 12" and 16".  We also do precast columns, beams, and wall panels.  My question is: we have our specific hollow core cross section already made in AutoCAD as a tool palette, is it possible to bring these templates in and use them when laying out our plank?  I ask this because the default hollow core you can download from AutoDesk Seek is not a correct representation of our hollow core slabs (see attached pdf).  Please keep in my mind this is a totally new program for us.  Any help our guidance would be greatly appreciated.

Thank you,

Jon

[Anonymous]

hello
you need to create new Revit family but you can use your cad file when sketch the new families

[Anonymous]

Ok, I drew our 10" hollow core from scratch in Revit Family.  But now it is importing the family into my project standing up and down instead of hozitonally.  Is there a way to "mate" two faces like in solid works/edge?  Also could you explain how to import CAD drawings into a family.  That would be a huge help seeing as we have all our templates drawn in AutoCAD 2013 Mech., just as 2d files though.

Thanks in advance,

JR

[Bob_Zurunkle]

You have to ask yourself first, what surface or workplane will your family be "hosted" to. At Unistrut our channels can run vertical, horizontal or diagonal. They also can have their back to a wall or ceiling, or run 90 degrees to each other. I drew my family horizontally, to get the backside to connect to a host. I added an instance parameter for the length, so that can be adjusted by the user in the project. I started by importing a 2D AutoCAD symbol, traced it, then removed it (see Managing Links). Yours might "host" to a ledge, but in our case we host to walls, decks, or beams, and sometimes to other Unistrut parts. Sometimes I have created a wall in a project, just to have a temporary item to host to (if there is nothing to begin with). Later I can delete the temporary wall. Yes items can be moved or copied away from their host, and the host can be eliminated.

Another thing to keep in mind is rotation. Families will usually only rotate in 2 axes but not the 3rd. There is a trick to creating a fmaily that rotates in all 3 axes if you really need that. Sometimes it is just easier to bring in a new copy of the item in the correct rotation. My main point here is as you manipulate your family in a project, you'll need to keep track of whether it's joined/disjoined, constrained or unconstrained. After awhile this becomes second nature, but it takes practice. Good luck!

[Anonymous]

Thanks for the response.  I have a follow up question.  I was able to model our 10" hollow core, with the correct orientation, in Revit Families.  I then imported the family into my project where I have my base walls down that our hollow core sits on.  My question is how do I trim up some of these pieces?  I have locked all aspects of the hollow core solid to its reference lines in the family in order to ensure the lengths can be changed effectively.  When I go to edit the slab lengths in my project, all the slabs lengths change.  I will also need to cut some notches in my hollow core for when the walls jog.  In summary I have three questions:

1.) What is the most effective way to trim these slabs?

2.) What the most effective way to cut notches into my slabs?

3.) I will also need to cut a "filler piece" (our hollow core slabs are 4' wide, in some/most cases we need to create a "filler" piece which is just a 4' piece cut to the dimension we need.  For example in this project I need a 30" wide piece instead of the typical 4' wide piece.  Do I have to create a whole new family and redraw this piece in order for Revit to properly show this?

I will attach my project file for a reference.

*edit: The file is too large to attach,  if you provide me your email I can send you the file via email.*

Thanks in advance,

JReck

[Bob_Zurunkle · Accepted solution]

Can't say I am an expert on joining stuff, but Revit Structure does have an option to COPE steel beams. I wonder if that would work for your case?

As for varying lengths of plank, I used an Instance Parameter in our families of channels (not a Type Parameter). Basically, in the Family Editor, I had one end of the channel tied to the origin point, and I created a reference plane parallel to the other end of the channel (I even named it, which is important later when you select it). Then I added a dimension to the reference line from the origin, BUT it seems I chose to create a parameter for its label. This I called Length and defined it as an Instance parameter, so each individual piece can be overridden in a project, instead of every instance changing the same (which is what a type parameter would do). Next I tied that end of the channel to that reference and locked it (very important). Locking them together means when you change the length to the reference plane, the object stretches with it. In your case you'l have to make sure both the solid and the voids' end points are tied to that reference plane.

Browse the Autodesk website for free downloadable Family Editor Guides for Revit Architecture and Structure. I think the Architecture one is current, while the Structure one may still be for 2010 (but the core stuff still provides valuable info). They explain with step-by-step instructions how to create a number of families, and you'll pick up on things that will help you with your own work. That's what I did! 🙂

[Anonymous]

Thanks Bob, I really appreciate your help!  Would you happen to know why in 3D views my hollow core has boxes off in the distance?  I have attached a screen shot for a reference.  These lines show up when I plot as well.  I just found out they also show up in non 3D views....

As far as my last post go this is how I solved the trimming aspect.  I simply made a duplicate of my family for 10" plank and editted the length to the correct length and wa-la! 

[Bob_Zurunkle]

Do these happen to show up in the Family Editor? I should add that one thing I did was I removed the sketch geometry I used to create the "solid" within in the family itself, after it was done. I also check my top/front/side views for any extraneous stuff that might need to be erased. I didn't ask what family you based yours on, but I used Generic -- Face Based.

Another thing I did do was add Invisible Lines as some of the guiding geometry in the family itself. these don't show up except as guides for positioning our channels and other parts fairly accurately, but they wouldn't plot.

Open your family and check all views for guiding geometry, erase what you don't need (including the original profile), and add any guidelines you may need, only as invisible lines. I hope this helps!