Simple Seashell

A while back someone posed a challenge to write an OpenSCAD script that would fit in a tweet.
https://www.thingiverse.com/groups/openscad/forums/general/topic:19876

This script was my contribution:

```
for(a=[.1:.05:4]){
rotate([0,a*90,0])scale(a)translate([10,0,0])difference(){
cylinder(2,10,10);cylinder(2,9,9);
}
}
```

After playing around with the code a bit I managed to print one, so thought I'd share my results. I had to lay it on its side and use support. Make sure you use the "Support on build plate only" (Slick3r) option unless you have soluble support material. Even then it can be tricky to get those thin vertical areas to print. Mine came out pretty rough but maybe that adds to the organic look?

The translate([0,0,-.1]) and extra .2 height on the inner ring is not strictly necessary but cleans up the render error in the preview. You could also increase the cylinder heights to get a solid body, but I like the skeletal look.

My favorite filament mate