difference() {
    cylinder(h = 7, d = 152.4, center = false, $fn = 100);
     translate([0, 0, -1])
      cylinder(h = 9, d = 146, center = false, $fn = 100);
    
    }
    
    
  //91 mm high
    translate([0,-22,61])
        rotate([90, 0, 0])
            cylinder(h = 7, d = 122, center = false, $fn = 100);
            
            
 
 translate([0,76,61])
    rotate([90, 0, 0])
       cylinder(h = 91, d = 122, center = false, $fn = 100);