Cast-In-Place Stair error

[rob.127056]

I keep getting an error that says "Can't make stair" while making a cast-in-place stair.
I have my stair set for maximum rise of 180mm which at a floor to floor of 3200mm means I need 18 risers at 177.77mm each.
However it won't let me make the stair. It works fine if I use an assembled stair with the same parameters. The only way I can get the cast-in-place stair to work is if I bump it up to 19 risers at 168.42mm but I don't have enough room for this extra riser.

Anyone else this problem? anyone have a solution?

Thanks.

[patricks]

Can you paste the offending elements into a separate file and post it?

*edit* also keep in mind that a monolithic stair has to begin with a riser at the bottom, and a tread at the top (usually the same height as the upper landing). An assembled stair will both begin and end with a riser at the bottom and top. I'm not sure how it works in 2013, but in previous versions a monolithic stair would have the same number of treads and risers (18 treads in your case, along with 18 risers), and the little notation next to the stair run sketch would say something like "-1 risers remaining".

[rob.127056]

Here is a file with the "cast-in-place" stair. Try a stair from Level B6 to Level B5. By the way B5 is the upper level.
Thanks.

[patricks]

Sorry to say I have no clue. 17 works fine even with the error that the risers are too tall. 19 works also. But it just doesn't like to make one with 18 risers for some reason.

I even changed the B5 level height. For some reason I think it has something to do with the level height, but what I don't know. 3000 works fine, 3100, up to 3192 works fine. Then 3203 on up works fine also until you exceed 3240 max height for 18 risers at 180. But anything from 3193 to 3202 breaks the stair. WEIRD!

[rob.127056]

Hmm. Maybe a bug?

[rob.127056]

UPDATE FROM AUTODESK SUPPORT

Thank you for choosing Autodesk Support.
I understand when you try making a Cast-In-Place stair, you are receiving a "Can't make stair" error.
I have been able to reproduce the error you are seeing, and I have logged this with our developers. I will let you know when I receive an update from development.
In the meantime, I have found that you can work around this by using Stair by sketch (available as a drop-down on the Stairs command).

[rob.127056]

UPDATE FROM AUTODESK

I have received an update from development, and they have also been able to reproduce the issue. They have found that an update to the Revit code is required to correct the behavior, and they have also found that the issue is related to the Structural Depth (family type parameter) of 150mm. If this is changed to 149, or 151, then the issue does not occur.

If you have no further questions, I will go ahead and close this case.