module 30fan() {
  difference()
    {
    linear_extrude(height=11, center = true, convexity = 4, twist = 0)
      difference()
        {
        square([30,30],center=true);
        difference()
          {
          circle(r=28.5/2,center=true);
          circle(r=18/2,center=true);
          }

        translate([+12,+12]) circle(r=3.4/2,h=12+0.2,center=true);
        translate([+12,-12]) circle(r=3.4/2,h=12+0.2,center=true);
        translate([-12,+12]) circle(r=3.4/2,h=12+0.2,center=true);
        translate([-12,-12]) circle(r=3.4/2,h=12+0.2,center=true);

      }

    }

    //Seven Blades
    linear_extrude(height=10, center = true, convexity = 4, twist = -30)
      for(i=[0:6])
        rotate((360*i)/7)
          translate([0,-1.5/2]) square([28.5/2-0.75,1.5]);
}


#%translate([0, 0, -5.5]) 30fan();

difference() {
    translate([0, 0, 11.5])cube([30+4.8, 30, 23], center=true);
    hull() {
        translate([0, 0, 8.5])cube([30, 50, 11+1.2], center=true);
        translate([0, 0, 17.6])cube([19, 50, 6], center=true);
    }
    translate([0, 0, 15.5])cube([19, 50, 21], center=true);

    translate([12.5, 0, 20]) cylinder(r=3.4/2,h=10,center=true, $fn=24);
    translate([-12.5, 0, 20]) cylinder(r=3.4/2,h=10,center=true, $fn=24);
    translate([-12.5, 0, 17.6]) cylinder(r1= 5/2, r2=6.4/2,h=6,center=true, $fn=24);
    translate([12.5, 0, 17.6]) cylinder(r1= 5/2, r2=6.4/2,h=6,center=true, $fn=24);

    translate([12,12]) cylinder(r=3.4/2,h=10,center=true, $fn=24);
    translate([12,-12]) cylinder(r=3.4/2,h=10,center=true, $fn=24);
    translate([-12,12]) cylinder(r=3.4/2,h=10,center=true, $fn=24);
    translate([-12,-12]) cylinder(r=3.4/2,h=10,center=true, $fn=24);
    rotate([0, 0, 22.5/2]) cylinder(r=28/2, h=10, center=true);
}