If I drew a flat 2D spiral is there a way to pin down one end and extrude the other end away into 3D space so it creates a shrinking stairwell?
Cool spiral maker. I just need a way to pop it into 3D uniformly. I can visualize the mechanics but am unaware of a tool for that.
I like Screw.rb. for a circular spiral. You can make a 3D thread. Yet if Curve-maker gives you a path, you can use that for upright extruder or Follow-me-and-keep.
Open the link that Dezmo gave you. Watch the video tutorial on the plugin page.
Enter the desired data from the keyboard to create the spiral, and you will also be able to set a height.
Otherwise, if you have a 2D spiral, you can use CurviShear to turn it into a 3D one.
You might also try Helix Along Curve - Create Complex Curves with Helix Along Curve - SketchUp Plugin of the Week #12 - YouTube
It lets you control height, number of revolutions, and inside and outside radius
I am not strictly concerned with spirals but any 2D paths that I want elevated into 3D.