union() {
  translate ([0, box_depth, box_height])
  rotate ([180, 0, 0])
  {
      // supports
      supports();
      difference() {
        // the box
        box_bevel(box_width, box_depth, box_height, box_corner_round);
        // remove the interior
        translate([box_tickness,box_tickness,-box_tickness]) 
            box_bevel(box_width-2*box_tickness, 
                      box_depth-2*box_tickness,
                      box_height, box_corner_round-box_tickness);
        // make dents for the cover
        pcb_cover_dents(1.5);
        // make the holes
        holes();
        }
  }

  union() {
    // reduce cover to fit, 0.5 mm in x and y
    scale([1-0.5/box_width, 1-0.5/box_depth, 1]) {
      // cover
      color("green") translate([box_tickness, box_depth+5, 0]) 
        box_bevel(box_width-2*box_tickness,  box_depth-2*box_tickness,
                  box_tickness, box_corner_round-box_tickness);
      // dents to lock the cover
      translate([0, box_depth+3-0.3, 0]) pcb_cover_dents(0);
    }
    // pcb foots
    translate([box_tickness, box_depth+5, 0]) pcb_foot();
  }
}