beams snapping to column centres

[Martin P]

OK...... I must be missing something, I have seen some impressive structural drawings done with Revit, and there are people using it in structural firms - posted on here. How on earth does everyone doing this cope with beams being forced into the middle of columns when you move either? I thought that this was pretty unanimously voted out as a bad feature before, but its still there.....

Somebody please tell me there is a logical non work around way to cope with this (ie BEAM OFFSET), I honestly cannot describe how much I detest Revit doing this, I mean Revit will MAKE a beam go slightly diagonal to keep this ludicrous relationship if I move a column by 20mm off the centre (which happens - ALOT!!!)- What it is the solution? I have heard 'worksets' mentioned to stop this happening, but I dont (need to) know how they work, and cant begin to imagine teaching the other users to use worksets simply to make a beam stay where they $%*@$%£ put it.......

Image attahced is a very normal situation to have, but Revit will not allow it.

[PeterJ]

And your beams are meeting square, wait til you bring one in at an angle....

It's very frustrating. Are you scheduling the beams/columns? It might be quicker to rework them as generic families. I haven't tried this yet but it seems logical as it would not force the structural relationships.

[sbrown]

I have a workaround, change the center of the column family so that it is not in the center of the column but the center of the beams.

[beegee]

I would go for the generic family option. - forget those structural families - too much hassle.

And Martin, when you think "worksets", just think "layers", the basic concept is quite similar, if you are using them for controlling visibility and constraining elements, rather than project sharing.

[anders.hedman]

I was struggling with the same problem with beams snapping to colums some months ago using Revit 6.1. It would be great if the automatic snap in the beam family easily could be turned on and of on the fly.

[PeterJ]

I have a workaround, change the center of the column family so that it is not in the center of the column but the center of the beams.
That's a step forward but it wouldn't be unknown for beams to attach to a column with a stagger. I think that generic families are probably the answer.

[Martin P]

So basically nobody likes it, it does not solve problems, it creates them..... So why is it still there? Everybody is having to work around this, that is not good.

I assumed structural improvements meant that this would be gone, this really has been mentioned so many times now..... Revit just cannot go moving beam ends, this is the very worst side of parametric Cad, I absolutely have to be able to switch this OFF!!!........

I apologise for ranting, but this has been a long standing problem I mention every release and I get the feeling that someody somewhere thinks this is what we want, I am going to start a poll on the wishlist, please vote we need to get this sorted out.

http://forums.augi.com/showthread.php?t=11254

[shaunv68276]

All I have done is altered the Beam family file. Try this family out it doesnt give you that offset from the column. Remove the constraints of the ends and stretch the ends to constrain to the length dim. thus removing the offset

[Steve_Stafford]

Martin have you been unable to do what you show in the picture? If so how did you make that image?

I experimented a little tonight and found that I could do what you describe even though the beams wanted to snap to the column location instead. I moved the beam and it gave me a warning about joining, then I dragged the drag handle of the beam back and then toward the grid line. I found that if I was careful to snap to the grid line instead of the column I could postion them freely.

If I placed a beam short of the column first then dragged the end over I could eliminate the move and error step.

I can relate to the dislike of the snapping but I think you can get what you need?

[Martin P]

Martin have you been unable to do what you show in the picture? If so how did you make that image?

I experimented a little tonight and found that I could do what you describe even though the beams wanted to snap to the column location instead. I moved the beam and it gave me a warning about joining, then I dragged the drag handle of the beam back and then toward the grid line. I found that if I was careful to snap to the grid line instead of the column I could postion them freely.

If I placed a beam short of the column first then dragged the end over I could eliminate the move and error step.

I can relate to the dislike of the snapping but I think you can get what you need?


Edit the height of your column - the beams will move. Move your column by a tiny amount, the beams will move to the centre.

There is no problem putting the beams in this location, the problem is making them stay where you put them. Worst is editing the column height - beams lurch into the column centre and you dont even see it. Editing the height of a column should not make a beam move........

[Steve_Stafford]

aaah...see what you mean. Not very friendly at all. I hoped the start and end release options affected this behavior but it didn't in my meager experimentation.


Unless the geometry is driving the relationship instead of the center reference plane, I suspect the immediate answer is a new beam family that is offset from center and provides a parameter for that offset value.

umm Mr. Campbell what say you?

[Martin P]

You're lucky it was an experiment :) - I found out about it in the middle of a project - all my beams went all over the place - very upsetting!! - long time ago, I pretty do beams all in place now to make sure it is not going anywhere.... Not a good solution though.

[Martin P]

All I have done is altered the Beam family file. Try this family out it doesnt give you that offset from the column. Remove the constraints of the ends and stretch the ends to constrain to the length dim. thus removing the offset


That works!!! superb, thank you...... Will re-create all the structural framing families like this.......

[Phil Palmer]

Martin,

You should not have to re-do all the structural beam families to accomplish something so bloody simple.
IF this is the way we should be using the families then REVIT should do the family amendments and post the set for everyone to download.
Its a crazy situation we have lived with for ages now !

[zbubbas]

Coming from a structural engineers point of view, I can understand why Revit wants to snap to the center. For the analysis of the beams and columns, the center of gravity of each beam must intersect with the center of gravity of each connecting member. If they don't intersect, they are, according to the model, not touching and are not connected. There are ways around this by adding a very stiff "element" to connect the offset member to the column for example. I'm not sure if this could be done in the when exporting or using a Revit model for structural analysis. It seams that this would be the best way to make the offsets work in Revit and still being able to use an analysis program. Just my two cents.

[mmodernc]

Jumping back to centre is especially nasty with concrete beams which are often designed to have one face in the plane of a wall below, adjacent etc rather than centred on grid. Does the structral tool set in Revit work for concrete? I thought you could set the offset in 7.0.
"Structural design and drafting Structural engineers and architects use the structural tools
in Revit for design and documentation.
New tools such as joist systems beam, set back controls,
brace controls, and column-grid attachments, make this
process even more streamlined.
X"

[Steven Campbell]

OK...... I must be missing something, I have seen some impressive structural drawings done with Revit, and there are people using it in structural firms - posted on here. How on earth does everyone doing this cope with beams being forced into the middle of columns when you move either? I thought that this was pretty unanimously voted out as a bad feature before, but its still there.....

Image attahced is a very normal situation to have, but Revit will not allow it.Sorry for not getting to this quicker, I was on vacation. Let me see if I am following this correctly you want a Beam Offset horizontally from the beam centerline.

Try this example so if it works the way you expected. Sorry it is Imperial... The Imperial was easier to fix because they were made with profiles. It probably needs some fine tuning but if it works the way you want I will make a few metric versions and post them here.

Steven Campbell
Autodesk Revit

[Martin P]

An offset wont really help me that often, but thank you for replying and looking at this. A common problem is when I have 2 different column sizes. When this happens it is very rare that it is the centres of the columns I will line up, it is usually the faces (against a wall or cavity or whatever)

An offet would not help in this situations as the beams will just go squint because the ends are forced to stick to the column centre. Where I have a column that is say 45 degrees rotated to the others at say the corner of a builing - Again it would be quite rare for the centres to line up perfectly and I will get squint beams.

The big problem is really the snapping to the centre of the columns at all. There is no need for this relationship, I can use a gridline and locks etc. It pretty much renders the actual beam families unusable in all but the most simplistic layouts for me.

[Steven Campbell]

I will forward the info to our Structural PM for review and analysis...