$fn=60;

render() difference() {
  // outer
  union() {
    cylinder(d=65, h=7);
    translate([0,0,7]) cylinder(d1=65, d2=52, h=30);
    for(i=[0:360/16:359]) rotate([0,0,i])
    translate([29.5,0,3]) hull() {
      translate([0,0,0]) sphere(d=6);
      translate([0,0,5]) sphere(d=6);
      translate([3,0,0]) sphere(d=4);
      translate([3,0,5]) sphere(d=4);
    }
  }

  // inner
  cylinder(d=6.5, h=100, center=true);
  cylinder($fn=6, r=10.5/sqrt(3), h=20);
  translate([0,0,20]) cylinder(r1=10.5/sqrt(3), d2=6.5, h=5, $fn=6);
}