Hi Gary, after you have drawn your helix and a closed profile curve, select the
profile curve and run the Construct > Sweep command.



The prompt in the upper right corner of the window will say "Select rails". Select the helix
as the sweep rail and push "Done" (or right click in the viewport).

In the command options for the sweep command set the "Twist" option to "Twist: Flat":





Push "Done" or right click in a viewport to exit the Sweep command and you'll have a solid.



- Michael