difference() {
    body_with_rounded_hole();

    trnalsate([
    resize([0, 0, 1.01])
    trace();
}

color("red")
trace();

module trace() {
    difference() {
        hull() {
            translate([19, 19, 0])
            cylinder(h=1, d=3, $fn=100);

            translate([19, 5, 0])
            cylinder(h=1, d=3, $fn=100);

            translate([65, 19, 0])
            cylinder(h=1, d=3, $fn=100);

            translate([65, 5, 0])
            cylinder(h=1, d=3, $fn=100);
        }
        
        translate([0, 0, -1])
        resize([0, 0, 3])
        hull() {
            translate([19, 19, 0])
            cylinder(h=1.02, d=2, $fn=100);

            translate([19, 5, 0])
            cylinder(h=1.02, d=2, $fn=100);

            translate([65, 19, 0])
            cylinder(h=1.02, d=2, $fn=100);

            translate([65, 5, 0])
            cylinder(h=1.02, d=2, $fn=100);
        }
    }
}

module body_with_rounded_hole() {
    body_with_hole();
    hole_rounding();
}

module body_with_hole() {
    difference() {
        body();
    
        translate([10, 12, -0.01])
        cylinder(h=7.02, d=12);
    }
}

module hole_rounding() {
    difference() {
        translate([10, 12, 2])
        cylinder(d=12, h=3);
    
        translate([10, 12, 0])
        cylinder(d=8, h=7, $fn=100);
    }

    translate([10, 12, 5])
    torus(r1=6, r2=2, $fn=100);

    translate([10, 12, 2])
    torus(r1=6, r2=2, $fn=100);
}

module body() {
    hull() {
        end();

        translate([52, 0, 0])
        end();
    }
}

module end() {
    translate([12, 12, 0])
    cylinder(h=7, d=20, $fn=100);

    translate([12, 12, 2])
    cylinder(h=3, d=24, $fn=100);

    translate([12, 12, 2])
    torus(r1=10, r2=2, $fn=100);

    translate([12, 12, 5])
    torus(r1=10, r2=2, $fn=100);
}

module torus(r1, r2) {
  rotate_extrude()
  translate([r1,0,0])
  circle(r2);
}