topic Re: Cant create an Oval Staircase in AC21 in Modeling

Cant create an Oval Staircase in AC21

Anonymous — Wed, 10 Oct 2018 03:47:21 GMT

Hi Guys,
Anyone know how to create an oval staircase? Ive tried everything including the magic wand, any tips?

Thanks,
Cain

https://imgur.com/a/kBrKY1w

Re: Cant create an Oval Staircase in AC21

Barry Kelly — Wed, 10 Oct 2018 05:48:00 GMT

The only way I can get it to work is to not use an ellipse.
Stairs seem to only like a constant radius for the curves.

So can you re-create the ellipse with 3 arcs instead?
It will create a node at each of the arc end points.
You will need all of these stair nodes to be 'winders' with equal goings.
You might have to turn some of the rules off for things like max going length and max 2R+G so the stair fits the length of the arcs.

Barry.

Re: Cant create an Oval Staircase in AC21

Anonymous — Wed, 10 Oct 2018 06:42:58 GMT

Thanks Barry I will try this.

Re: Cant create an Oval Staircase in AC21

Anonymous — Mon, 14 Jan 2019 04:57:29 GMT

Hi Guys,

I thought I would give this a bump.

Im still unable the get the exact tread layout as per picture?

I can edit the stair treads to shape, however I lose the formation of the stringers(to shape with treads) and the function of the stair (becomes an object).

Thanks,
Cain

Re: Cant create an Oval Staircase in AC21

Anonymous — Sun, 11 Aug 2019 21:35:28 GMT

Update:

AC21 cannot do the elliptical shape i required, neither could Revit, ended up using Autocad and Sketchup.

Re: Cant create an Oval Staircase in AC21

Hmooslechner — Wed, 14 Aug 2019 15:55:15 GMT

Archicad makes some silly things at stringers by complex stairs. But there are other things that can be done about this: Use Profiles and Morphs. (Also maybe helpful - the use of the railingtool with the profilemanager.)

a try to get it working:

Re: Cant create an Oval Staircase in AC21

Steve Jepson — Wed, 14 Aug 2019 23:40:22 GMT

whatwaitnow wrote:
Update:

AC21 cannot do the elliptical shape i required, neither could Revit, ended up using Autocad and Sketchup.

Is it mandatory that you use the Stair Tool? Otherwise, any stair can be modeled with ArchiCAD exactly how you need it to be. You do not need to use any other programs.

Re: Cant create an Oval Staircase in AC21

Anonymous — Thu, 15 Aug 2019 09:18:43 GMT

Hmooslechner wrote:
Archicad makes some silly things at stringers by complex stairs. But there are other things that can be done about this: Use Profiles and Morphs. (Also maybe helpful - the use of the railingtool with the profilemanager.)

a try to get it working:

I could do an oval shape, just not the specific oval shape required for compliance and ascetics.

Re: Cant create an Oval Staircase in AC21

Anonymous — Thu, 15 Aug 2019 09:19:57 GMT

Steve wrote:

whatwaitnow wrote:
Update:

AC21 cannot do the elliptical shape i required, neither could Revit, ended up using Autocad and Sketchup.
Is it mandatory that you use the Stair Tool? Otherwise, any stair can be modeled with ArchiCAD exactly how you need it to be. You do not need to use any other programs.

Yeah much preferred to use the stair tool, so i could make small changes, ie, risers, widths without redoing the whole structure.

Re: Cant create an Oval Staircase in AC21

Steve Jepson — Thu, 15 Aug 2019 15:56:35 GMT

I understand. The Stair Tool is great for easily adjustable approximations, and sometimes that's all you need.

Re: Cant create an Oval Staircase in AC21

Barry Kelly — Fri, 16 Aug 2019 02:47:55 GMT

Looking at this again, the risers of your oval stair all emanate from one central point.
So create a large circular stair and then adjust the stair boundaries (not the baseline - leave that circular) and you may be able to get what you want.
Add nodes to the arc and adjust the edges to match the curve of your oval.

I just had a go tracing over your image but I can't get the top point of the stair to pull down enough to match your oval.
Close but not quite.
It seems there is a limit to how yo can adjust the boundary - which I am a little surprised at.
Yours may work as you have a more accurate drawing rather than an image I copies from the forum.

An alternative would be to create a slab with an oval shaped hole and the Solid Element Operate this with the stair to cut the shape away.

Barry.