Coils and Turnarounds

I like to study different techniques at different times. Some depending on the students, others depending on the level of difficulty.  So over the past month, I've been considering how to make coils and round-edged objects.  How did I learn?  Tutorials and trial and error.  I started with WikiHow.  It is my go-to tool for 3d printing.  If I want to learn something, I start with WikiHow. Design a Rope Coil.

Then I watched a YouTube video but I got stuck for hours on using the rotation tool.  I'll never get those hours back!  But it is an interesting viewing.