// Borromean rings
// make with support angle 10, infill 90

a = 20;
b = 10;
r = 3;

k = 60;

module ring(){for (i=[1:k]){
 hull(){
  translate(v=[a*cos(i*360/k),b*sin(i*360/k),0])
     sphere(r=r);
  translate(v=[a*cos((i+1)*360/k),
              b*sin((i+1)*360/k),0]) sphere(r=r);}
}}

ring();
rotate(120,[1,1,1]) ring();
rotate(240,[1,1,1]) ring();