$fn = 80;


difference() {
    union() {
        difference () {
            cylinder(10, r1=5, r2=0);
            translate([0, 0, -0.1]) scale(0.95) cylinder(10, r1=5, r2=0);
            translate([0, 0, 10]) cube(3, center=true);
        }

        translate([0, 0, 8])
        cylinder(2, r=1);
    }
    #translate([0, 0, -0.1]) scale(0.95) cylinder(15, r=1);
}

difference() {
    translate([6, 0, 0.251]) cube([3, 3, 0.5], center=true);
    cylinder(10, r1=5, r2=0);
}