Create an L-shape or U-shape winder run component by specifying the lower endpoint of the run. 
The winder run will automatically connect the base and top elevations. (L-shape winder is used for illustration in this procedure.) 
 Video: Create a Winder Stair
 Video: Create a Winder Stair 
To create a winder run
-  Select the winder run component tool and specify initial options and properties. 
  See 
	 Selecting the Run Component Tool and Specifying Options. 
   
-  On the Options Bar, for Location Line, select either Exterior Support: Left or Exterior Support: Right if you are aligning a run with supports to a wall. 
  For aligning a run without supports, Exterior Support: Left and Run: Left have the same alignment behavior (as do Exterior Support: Right and Run: Right). 
   
- On the Options Bar, clear or select Mirror Preview to change the default winder layout direction. 
-  Press Spacebar to rotate the shape of the winder run so the turn is facing the required direction. 
-  If positioning the run against a wall or other element, move the cursor near the wall, and notice that the winder stair snaps to position against the wall. 
- Click to place the winder run. 
  
 
-  Use the direct manipulation controls to relocate a run leg or balance the steps between the winder legs, as well as to modify other layout properties. 
  See 
	 Modifying Stair Components Using Direct Manipulation Controls. 
   
-  Optionally, you can replace winder steps at the beginning and end of the run with straight (uniform) steps. 
  - Select the run. 
	 
- On the Properties palette, under Winders, enter the desired number of uniform steps for Parallel Treads at Start and Parallel Treads at End. 
		 In the following image, 3 parallel treads were specified at the start and end of the winder run. 
		   
 
- Optionally, on the Quick Access Toolbar, click 
   (Default 3D View). (Default 3D View).
- On the model panel, click 
   (Finish Edit Mode). (Finish Edit Mode).