Thanks!
The syrup bottle lesson used array along curve and Mary set the profiles to roadlike before doing the sweep, which is nifty.
I saw that Pascal does one revolution with RailRevolve, and then just stacks as many thread as he needs. I did one rev with Sweep1 and stacked them. Pretty straightforward after fixing the Roadlike potholes. More than one means to an end.
That’s for another day, or week! Right now I’m busy with drawing and making a small saw arbor for my CNC machine, and in my case threads on the drawing are just for show - although now I have a 3D printer. 