Custom step going depth & rise for existing buildings

[Kpetrocheilou]

When we work on existing buildings, sometimes we need to create a customized stair with different going depths, that don't follow rules and are not all equal in the same stair. There should be an option to customize the stair structure in terms of going depths and rises.

[Laszlo Nagy]

It is possible to do both.

To customize the Riser Height, go to 3D, enter Edit Mode, then select a Tread, click its front or back edge, and use the Pet Palette command to adjust its Z Offset value.

In the case of Risers, you can select their endpoints and drag them. You have to drag both endpoints to achieve the horizontal offset.

This is the results after custinizing both Riser Heights and Treead Depths.

You will notice that there are gaps in the structure. This is because the Stair will always keeps the specified minimum structure thickness (e.g. 150 mm), and will always "pull back" the structure at the back of risers until it reaches this minimum thickness, and then starts the next riser.

I drew a red line in 3D using the Morph tool to illustrate this minimum structure thickness.

 

So, the way I would model these custom riser heights and tread depths is by considering this minimum thickness rule, then I would have those "holes" in the Stair structure, which I would just fill using Slab or Morph elements that have the same Layer, Building Material, and Uncut Pen as the Stair Structure. Here is the final result:

 

[Kpetrocheilou]

Hello Laszlo! Thank you for your prompt reply!

I didn't know anything about the custom heights and it looks effective!

But the solution for the custom depths is not really effective. If the rule of 150mm structure thickness, that you mention, is met, why the structure is not automatically adjusted, as it happens with the risers? In my case the stair has some goings that are narrower than others and the structure is visible over the finish. 

What would you suggest in this case? Cause solid element operations are not visible in the floor plans right?

[Laszlo Nagy]

Unfortunately, subtraction will not work. Only the whole Stair can be used as a Target for SEO so if you perform a subtraction SEO on it, it will cut Treads/Riser as well, not only the Stair Structure.

So, I think we can work out how to do it from this limitation. Our goal is to not have to move any of the Riser back (increasing the depth of the Tread). Moving Riser forward (towards the start of the Stair) is OK becuse then they will leave holes in the Stair Structure that can be filled.

So, I think I would find which Riser is farthest offset, and use that as a basis. This coud also mean that you would have to modify the position of most of the Treads and Risers.

Let me show you what I mean.

Below is a simple example. Let us say the black fill shows a normal Stair , and the red outline shows the inteded Stair with custom Tread Depths and Riser Heights. If you look at it, you can see that Riser 2 is the one that protudes forward (to the left in the image) the most relative to the normal Stair.  

 So, if you shift the red geometry to the right by that distance, you will achieve a situation where Riser 2 in the custom Stair will align with Riser 2 of the normal Stair, and you will need to shift all custom Risers backward to achieve your intended custom geometry.

 

You will also need to slightly adjust the thickness, plus Upper and Lower connection geometries to align with the normal geometry. But this will make it possible to adjust all needed Risers and Tread and not have to perform a Subtraction SEO on the Stair.

I hope this explanation makes sense.