module innerCircleCutter(height,dia,roundRad){
    translate([dia/4,0])
    difference(){
square([dia/2,height],center=true);
translate([(dia/4),0]) {
    square([roundRad,height-roundRad],center=true);
    translate([0,(height/2)-roundRad/2])circle(d=roundRad,$fs=0.2);
    translate([0,-((height/2)-roundRad/2)])circle(d=roundRad,$fs=0.2);
    }
}

}

module roundedThroughHole(height,dia,roundRad){
    rotate_extrude(){
        innerCircleCutter(height,dia,roundRad);
    }
}

roundedThroughHole(10,20,5);