Parametric Jingle Bell

This OpenSCAD script will generate a traditionally shaped spherical jingle/cat bell

A user can choose the radius, wall thickness, size of the rim and also if it has features such as a hole in the top or an internal ball and if the ball has a column beneath it for support.

Note:
Rendering this file with a large value for $fn will take quite a while. For the provided .SCAD file with $fn=100 it took about 20 minutes on a modern core i7 laptop.

To-do:
add option for 2 halves in side by si