How would you model a sinuous stair stringer and stair soffit?

[billiam]

Reaching out to the experts on how to go about this. We have a multi-level stair placed in a tower very similar to what's shown in the photograph below. I was able to accomplish modeling the stair itself but we would also like a sinuous curve on the stringer and underside of the stair, as shown in the last photos (except we have landings). Any ideas how to go about modeling this in Revit?

thanks in advance!






curve:

[Exar Kun]

A railing profile is probably your best place to begin although it would still require quite a bit of tweaking.

[snowyweston]

Img.#1 has landings, as does your model, Img.#2 & Img.#3 do not.

How do you imagine the underside of the curve to work at the landing of your stair?

How would I model it?

A loaded component, potentially a mass if the balustrades are to be lined sheet materials that could be basic walls applied by face once the (mass) family is loaded into the project, more probably a casework family with loaded children to better schedule parts.

Not every stair must be a (Revit) stair.

[kamranmirza]

Children ? Cruel !

[snowyweston]

Children ?

and rich ones at that!


Come on billiam, we've not had a good "how would you" thread in a while, let's get the chatter going...

[billiam]

sorry everyone, truly at a loss here! I've managed just about every detail for this stair except for this remaining curve!! The issue I'm facing with an In-Place model is that no matter which operation I choose to make a form, (Sweep, Extrusion, etc..) I'm limited to a single work plane in a 3D environment. It would be great if I could make a blend for example to sketch a line on the face of one stringer, then switch work planes to a perpendicular stringer and keep sketching, but that is not an option.

I've also tried creating a sweep along model lines which mimic the winding stairs, but the orientation of the profile never adjusts correctly after taking a corner. Seems like I'm also limited to using only one profile for that command. So I tried using a sweep blend, however that operation has to fit two profiles on a single line, and my model lines are segmented.

snowyweston - unfortunately I can't quite visualize in my head how to go about using a loaded component, that might be above my pay grade. Especially because the curve I want takes a form similar to a Nascar track, meaning the radius widens out and changes in height.

See the image I've attached below, these are the model lines i'm using to mimic the edges of the curve I need. Now I just need to find a way to blend these lines together. I know an image isn't great - i'll try to find a way to send the entire model of the stair, as of now though it lives within the model of the entire house.



Thanks for all your input!

:beer:

[JeffH]

Here is something I tried and threw together in a couple of minutes. it might get you somewhere further down the line. I made the stair "enclosure" in this image with an in-place model using a swept blend. Circular path with the 2 profile offset from each other in the "z" direction. That give the flowing rails and under side. Then would continue to add steps into it with extrusions. I just did one at the bottom, but there is no reason those could not be arrayed. You might even be able to get a regular stair element to fit in there with some work. I just too a stab at the main form quick.

[billiam]

JeffH - Thank you for the inspiration! After a lot of trial and error I finally have something close to the result we're after. It's not yet perfect as the sweep needs to be cleaned up in some places, but I'm glad to finally have something.

I ended making a series of sweep blends as JeffH mentioned, however since the sweep blend tool is limited to following only a single curve (instead of multiple segments like you can do with a normal sweep) I had to mirror my form and offset the Z-axis of the profiles as I moved up the stair.

then I used voids, and a lot of them to make sure my form fits snug under the stair treads and follows both the interior and exterior boundary that I needed. It was somewhat of a messy process and hard to reproduce but hopefully this gives some idea how it can be done in Revit and leads to improvements

thanks!






here is the isolated form with the stairs 'carved out' using voids

[snowyweston]

I'm pretty sure you're more seeking solutions than inviting comment, but the shape looks tortured - the inner stringer especially.

Since (going off the plan in the OP) the outer stringer will be hidden by the circular stair containing wall, I'm not seeing what is being gained here.

[billiam]

I'm pretty sure you're more seeking solutions than inviting comment, but the shape looks tortured - the inner stringer especially.

Since (going off the plan in the OP) the outer stringer will be hidden by the circular stair containing wall, I'm not seeing what is being gained here.

The outer string is hidden but the form still represents what we needed for the underside of the stair, a little confused by your comment.

and yes, inviting both comments and solutions