Concave Fidget Caps - No Supports

I found plenty of concave fidget spinner caps but almost all of them required printing with support material except [Turrboenvy's](https://www.thingiverse.com/thing:2248044) remix of [ftwelve](https://www.thingiverse.com/ftwelve/about)'s ["Textured Concaved Fidget Caps"](https://www.thingiverse.com/thing:2049812). I wanted the caps larger than ftwelve's design. I finally was able to understand [rcolyer](http://www.thingiverse.com/rcolyer/about)'s [openscad screw library](http://www.thingiverse