fn = 50;

difference(){
    union(){
        translate([-32.5,0,0])
            hull(){
                translate([1.5,0,0]){
                    cylinder(h = 16, r = 4.5, $fn = fn);
                }
                translate([-1.5,0,0]){
                    cylinder(h = 16, r = 4.5, $fn = fn);
                }
            }
        translate([32.5,0,0])
            hull(){
                translate([1.5,0,0]){
                    cylinder(h = 16, r = 4.5, $fn = fn);
                }
                translate([-1.5,0,0]){
                    cylinder(h = 16, r = 4.5, $fn = fn);
                }
            }
        intersection(){
            hull(){
                translate([-34,0,5])
                    cylinder(h = 100, r = 4.5, $fn = fn);
                translate([34,0,5])
                    cylinder(h = 100, r = 4.5, $fn = fn);
            };
            difference(){
                translate([0,0,-70])
                    sphere(r = 95, $fn = 5*fn);
                translate([0,0,-70])
                    sphere(r = 90, $fn = 5*fn);
            };
        };
    };
    translate([-32.5,0,-2]){
        linear_extrude(height = 18, center = false, convexity = 10, twist = -9*360, $fn = fn) {
            translate([.25,0,0])
                circle(r = 1.75);
        };
    };
    translate([32.5,0,-2]){
        linear_extrude(height = 18, center = false, convexity = 10, twist = -9*360, $fn = fn) {
            translate([.25,0,0])
                circle(r = 1.75);
        };
    };
};