# How to Create a Half-Turn Staircase?

I would like to create a half-turn staircase without a landing. Is there an easy way to accomplish this without having to manually calculate and create each step individually?

Here’s an image similar to what I would like to achive:

I have found the Archimesh add-on including this tutorial for creating curved stairs. While I can bend the created stairs, I haven’t found any way to get anywhere close to the image above. My stairs just always look out of shape and I don’t know how to get the outline of the staircase into a square.

I should mention that I only have very little experience with Blender modeling, so it’s well possible that I’m just missing some curve modification basics. Perhaps Archimesh is also the wrong approach for this in the first place?

• This is complicated enough you should probably model it by hand, I don't know if Archimesh can do this. Commented Nov 6, 2016 at 18:58
• Probably the Curve and Array modifiers + a bit of tweaking and polishing can do the job. To bad I haven't got time to check it out right now :(. Commented Nov 6, 2016 at 19:41
• Try an array modifier controlled by an empty. Rotating the empty will give you the rotation on the steps. Then just add a boolean to keep the shape of the stairwell. Something like this: i.sstatic.net/CG1z6.png
– user1853
Commented Nov 6, 2016 at 20:17

As mentioned in the comments this a complex enough that it might warrant modeling it by hand. If, however, you don't need an extremely clean topology you can easily do it with a combination of an Array + Boolean modifier. At least the radial part that is, the other one seems simple enough to do separately by hand.

Create your step as a mesh object, but make sure it is a closed, manifold solid object (you'll need it later for a Boolean modifier).

Add an array modifier to it, set the $$Z$$ offset to the desired height of the step and set it to Object Offset

Now add an Empty object to the scene; it needs to have the same $$X$$, $$Y$$, and $$Z$$ scale as the mesh object, or the stairs will [progressively scale either larger or smaller]Why is the array modifier scaling my object?)).

Give it the exact rotation you want between each step. Say you want $$12$$ steps in the curve part, that will go around $$180º$$, then you have $$180 º / 12 = 15º$$, so rotate the empty $$15º$$ about the $$Z$$ axis and point the Array modifier Object Offset to it.

When you have the array set up, just add a new mesh object with the exact shape of the staircase boundary, a simple box will do. Making sure the steps are large enough to cover the whole volume.

Now add a Boolean modifier and you are all set. If you get any artifacts with the Boolean operation be sure to leave a small gap between each step.