Creating cool spiral staircases is no longer a daunting and tedious task! Here is a simplified method which will allow you to easily build spiraling staircases.
Step 1: Create a Cube (Objects=>Primitive=>Cube). Double click on the cube icon in the object manager and change the settings to X=700m, Y=100m, Z=200m, with 10 segments for X and 5 for Z. Check the box for Fillet and input 5m for the size. Rename the cube 'Step'
Step 2: Next you'll use the Duplicate function to create a bunch of these steps for the stairs. Go to Functions=>Duplicate to bring up the Duplicate dialog box. Here's where you'll decide how many steps you want your staircase to be. Each step will increase the Y position by 100m and the Z position by 125m. So if you choose to have 8 steps you should enter '8' in the 'Copies' text field (Be sure to check the box for 'Generate Instances'), 800m in the Y Position field (8 copies * 100m) and 1000m in the Z Position field (8 copies * 125m). Do the math to calculate the numbers for more or less steps.
Step 3: Clicking OK in the Duplicate dialog will present you with your staircase. Time to add the spiral effect. Group together the Step object and the Null Object group containing your instanced Steps. Name the group 'Stairs'. Bring in a Bend Deformer (Objects=>Deformation=>Bend). In the coordinates manager input 90 for P under Rotation. This will set the Bend up for a horitontal deformation instead of a vertical one.
Step 4: Drag and drop the Bend Deformer into the Stairs group. Now double click the Bend icon in the object manager to change its settings. Set the mode to 'Unlimited' and enter 30 in the Angle field. Click OK. You can also drag the orange control handle of the bend deformer to adjust it, but be sure that your bend is restricted to only bend horizontally and not vertically.
Step 5: You can also add railing structures to the steps if you'd like. The easiest way to create something like this would be to create a Rail post using LatheNURBS, and then draw out a path spline along the edge of the stairs. Make 8 copies (Use the Duplicate Function) of the Rail Post and then use the Arrange function to place the posts along the spline path. Drag the original post object into the duplicate object group and then with that group of posts selected, go to Functions=>Arrange and type the name of the Path Spline in the dialog box. You may have to tweak the positioning of the individual posts so they fit the stairs correctly.
Step 6: You can now move the spline path on top of the posts and sweep a circle or rectangle spline along it to create the handrail. Again, tweaking may be required with the spline points to get the railing looking right.
