Pool chlorine floater 3'

This is a chlorine pool floater with a screw top it works with standard 3' chlorine tablets. Feel free to customize it. Basically all of the important variables are at the top.

The code uses the following libraries:
https://github.com/openscad/scad-utils.git
https://github.com/openscad/list-comprehension-demos.git

And also some code lifted from here:
https://hackaday.io/page/5252-generating-nice-threads-in-openscad
.