$fn= 150;
difference() {
  hull() {
    translate([8,0,0])
    cylinder(h=9, r=6, center=true);
    translate([-8,0,0])
    cylinder(h=9, r=6, center=true);
    translate([0,8,0])
    cube([30,1,9], center=true);
  }  
  hull() {
    translate([4,1,0])
    cylinder(h=12, r=4, center=true);
    translate([-4,1,0])
    cylinder(h=12, r=4, center=true);
  }  
}