difference(){
    union(){
        difference(){
            difference(){
                difference(){
                    cylinder(45, 60, 60);            
                    cylinder(45, 50, 50);
                }
                translate([0, 0, 18.5])    
                cylinder(2.5, 53, 53);    
            }
            translate([0, 0, 34])
            cylinder(2.5, 53, 53);
       }    
       difference(){
            union(){
                translate([0, 84, 0])
                cylinder(35, 25, 25);
                translate([-25, 54, 0]) 
                cube([50, 31, 35]);
            }   
            translate([0, 84, 0])
            cylinder(35, 5, 5);          
      }
    }
    difference(){
        translate([0, 0, 10])
        cylinder(15, 150, 150);
        translate([0, 0, 10])
        cylinder(15, 60, 60);
    }
}