difference() {
    cube([15, 2, 17]);
    translate([10.5, -1, 8.5])
        rotate([0, 90, 90])
            cylinder(4, d=3.5, $fn=100);
}

cube([2, 24, 17]);
translate([0, 17, 0])
    cube([13, 2, 17]);
translate([0, 23, 0])
    rotate(5)
        cube([13, 2, 17]);

intersection() {
    translate([-3, 0,  8])
        rotate([0, 45, 0])
            cube([6, 17, 6]);
    translate([0, 0,  4])
        cube([6, 17, 8]);
}

intersection() {
    translate([1, -6, 0])
        rotate(45)
            cube([9, 9, 17]);
    translate([0, 0, 0])
            cube([9, 9, 17]);
}


intersection() {
    translate([1, 12, 0])
        rotate(45)
            cube([9, 9, 17]);
    translate([0, 8, 0])
            cube([9, 9, 17]);
}

intersection() {
    translate([1, 16, 0])
        rotate(45)
            cube([4, 4, 17]);
    translate([0, 15, 0])
            cube([9, 9, 17]);
}

intersection() {
    translate([1.5, 21, 0])
        rotate(45)
            cube([4, 4, 17]);
    translate([0, 15, 0])
            cube([9, 9, 17]);
}