$fn = 60 ;

union() {
translate([0,0,2])
  rotate([45,0,0]) {
    minkowski() {
      cube([60,30,2]);
      sphere(r=2);
    }
  }
  hull() {
    translate([20,30,2]) sphere(r=2);
    translate([40,30,2]) sphere(r=2);
    translate([30,0,2]) sphere(r=2);
    rotate([45,0,0]) translate([50,30,2]) sphere(r=2);
    rotate([45,0,0]) translate([10,30,2]) sphere(r=2);
  }
}