To add the propeller, trace the propeller piece onto cardboard and cut it out. Cut a hole in the front of the box large enough to accommodate a dowel that is 1/2-inch in diameter. Cut a hole in the center of the propeller and push the dowel through the propeller and through the hole in the front of the box. Hot-glue the red propeller center once the paint is dry to the front end of the dowel. The propeller should be able to rotate freely around the dowel. We recommend trimming the dowel’s length before you attach the propeller; the length of the dowel will depend on the size of your box.