module hour_hexagons(D,spacing) {
    for(dot=[0:15:360]){
        $fn=6;
        translate([sin(dot)*(D/6*spacing),cos(dot)*(D/6*spacing),0])
        color("black")
        rotate([0,0,30-dot])
        circle(D/24);
    }
}

hour_hexagons(16,4.5);