translate([0,0,10]) cylinder(r=10,h=10);
cylinder(r=5,h=20);
cylinder(r=1,h=30);
translate([30,0,0]){
        difference(){
            union(){
                translate([0,0,10]) cylinder(r=10,h=10);
                cylinder(r=5,h=20);
            }
            cylinder(r=1,h=20);
        }
    }