Beam system floor...

[phehir78]

Hi All,

I’ve drawn a hollowcore slab (using a beam system). I’ve added a RC Beam along the external leaf wall (which the hollowcore slab will sit on).

When i change the level of this beam to -400mm from the floor level (so as to position the beam under the slab), parts of the hollowcore slab are dragged down with the beam. I’ve attached a couple of screen shots.

All the hollowcore slab is drawn as the same beam system, so i don’t understand how parts of it are being dragged down out of position.

Any ideas?

Thanks.

[staylor · Accepted solution]

I had a similar situation. My company produces hollowcore slabs, so I do slab layouts all the time. When I first started using Revit, I used a Line Based Generic model to create the hollowcore family. The random problem, was when two slabs beared on the same beam or wall and got close end to end, they would automatically join. I couldn't get it to not join. I have since revamped the family using just a straight generic model with parameters controlling the length and width. Haven't had a problem since.

So to maybe answer your question, I believe it has something to do with the hollowcore trying to join with the beam. As they are the same type of system.

[Rafal.Gaweda]

...or maybe this way:

[Anonymous]

Is it a structrural framing? 

Perheps you could change the model behavior in the family editor? 

[phehir78]

Hi staylor,

Thanks for your reply, really appreciate it.

Not exactly sure what you mean by 'straight generic model with parameters'.

What steps would i need to set that up for a hollowcore slab?.

I've found with the beam system i was using, if i selected the slab, and  edited the work plane for

it, and also edited the geometry of the slab (beam/column joins) it made some difference with the problems i was having.

But its still not quiet working out for me.

Part of the HCU slab is being affected by a internal blockwall below [which is doing my head in 😞 ].

I've attached a couple of screen shots (3d view), which shows part of the problem.....one with the wall below shown (which effects how far the slab outline extends), and one with that wall deleted. Don't know why the 2 elements are joined?!...

Thanks,

Peter.

[phehir78]

Hi Merlijn,

had a look in the family editor.

Not sure where to find the option to change the model behavior though?.

How do i find that?.

Thanks,

P.

[staylor]

Sorry for the misunderstanding. Use "Generic Model" for your family template instead of "Generic Model - Line Based" and use reference planes and a parameter to control the length. The parameter will need to be set up as "instance" and not "type". I attached a Ref Level screenshot.

Hope this clarifies.

[phehir78]

Sound staylor, thanks alot for that.

Will give that a go.

I seem to have solved the problem with the HCU slab being effected by the wall below....i clicked on the wall, and in the Properties tab I unselected 'Structural'.....the wall then disappeared from my 3d view and the slab extended out to the outline i wanted it to. Then i reselected the 'structural' description for the wall again, the wall reappeared on my view, but the HCU slab stayed the way i wanted it.

Seems strange that that worked (as i basically didn't change anything, just switched 'Structural' OFF, then ON again), but it did for some reason.