How would you build the top rail for a handrail of a spiral stairs

[Glenn Woodward]

Joe,

I have had a good look at the dbx, and I know those settings are there.
But giving the Start Z and End Z different values doesn't create a helix - it just tilts the arc in 1 plane.
Can you demonstrate to me how you can create a helix from a 3D molding polyline arc (say an arc covering 300°).
Or drag one of your arcs so that it nearly forms a circle.
No point doing it with a small arc, because you cant see the result.

I maintain that you can't create a helix from and arc - but I am always willing to be proved wrong.
What I believe you are doing is tilting the arc in one plane and ending up with this: