board_width = 78.0; board_length = 90.0; case_depth = 10.0; wall_thickness = 2.0; board_thickness = 1.0; column_side = 4.0; union () { difference () { cube (size = [board_length, board_width, case_depth + wall_thickness]); translate (v = [wall_thickness, wall_thickness, wall_thickness]) { cube (size = [board_length - 2 * wall_thickness, board_width - 2 * wall_thickness, case_depth]); } } translate (v = [wall_thickness, wall_thickness, wall_thickness]) { cube (size = [column_side, column_side, case_depth]); } translate (v = [wall_thickness, board_width - wall_thickness - column_side, wall_thickness]) { cube (size = [column_side, column_side, case_depth]); } translate (v = [board_length - wall_thickness - column_side, wall_thickness, wall_thickness]) { cube (size = [column_side, column_side, case_depth]); } translate (v = [board_length - wall_thickness - column_side, board_width - wall_thickness - column_side, wall_thickness]) { cube (size = [column_side, column_side, case_depth]); } }