include <BOSL2/std.scad>

top_height = 10;
top_w = 1;
bottom_height = 25;
width = 7;

t = 2;

$fn=36;
linear_extrude(t) {
  stroke([[-width/2,0], [-width/2, -bottom_height]], width=t);
  stroke([[width/2,0], [width/2, -bottom_height]], width=t);
  yflip() fwd(width/2) stroke(catenary(top_w, droop=top_height), width=t);
  difference() {
    stroke([circle(d=7)], width=t);
    left(50)  xrot(180) square([100,100]);
  }
}