Introduction: Stadium Automata

For my technology, engineering, and design class, I was assigned to create an automaton out of materials that I had around my house. It was required to have at least 3 moving parts and a theme, which, given the fact that most sports have been canceled due to the COVID pandemic, I chose to make sports-related. My final project is my attempt at creating a sports stadium, complete with four rows of fans that move up and down.


For the project, I used materials that can be easily found around the house. These included:

  • Cardboard (about 1/4 inch thick)
  • Packaging tape
  • A hot glue gun
  • 2 different types of straws (thick, stiff larger straws and thin, skinny martini straws)
  • An Exacto knife and scissors
  • A tape measure
  • A black Sharpie

Step 1: Measuring and Cutting the Base Cardboard

To begin, I took a large piece of cardboard and measured out the sides of the box and wheels which I would need to construct the automata. I cut out an 8*6 inch piece for the front, two 8*10 inch rectangles for the top and bottom, and a 12*8 inch piece for the back of the automata, 6 inches of which would support the rest of the automata and 6 inches of which would function as the backdrop for the display. I also cut out 9 wheels with a 1.5-inch diameter, 8 of which would serve as the wheels to raise and lower the fans and 1 which would serve as the turning mechanism for the axel, a stiff straw which can be seen in the second picture above. As some of the cutouts had folds in them from the box I had cut them from, they were reinforced with two layers of packaging tape wrapped around the piece along the fold.

Step 2: Measuring Out the Axle

After cutting out all of the necessary pieces of cardboard, I then measured out how long the axle would have to be, and where it would insert into the 6*8 and 12*8 segments. After gluing two of the straws together for added length, I then glued one of the 10*8 pieces at a 90-degree angle to the 6*8 piece, forming the bottom and front of the automata. I then measured and poked a hole roughly the same size, if not a little larger, as the straw into the front piece, which was placed 3 inches upward into the cardboard, and 4 inches inward from the left or right side. I did the same with the 12*8 piece, and after forming the hole, I glued the 12*8 piece to the 10*8 base at a 90-degree angle, creating a solid foundation to build off of and securing the axle in place. Note that the axle was not yet secured in place, as the cams had not yet been added on.

Step 3: Creating the Cams

To create the cams, I first glued 2 of the cardboard circles I had cut out together. After the glue had dried, I made a hole with the pencil (although an actual drill could have been used as well) which was close to the edge of the circle. I then added hot glue in places along the wheel which were jagged or where the wheels didn't align, covering it afterward with a layer of tape to help the wheels spin better and to even out the glue. I then repeated this process 3 more times for a total of 4 cams. I then fitted the cams 1 inch apart from each other along the axle, gluing them in place as well so that when the axle was turned, they were as well. I glued the last singular 9th wheel to the end of the axle which protruded from the front end of the automata, making a hole that went through the wheel but did not poke through to the other side. This wheel served as the turning mechanism, and spinning it would turn the axle and cams as well.

Step 4: Finalizing the Project

To set up the displays themselves, I first cut 4 sets of 2 holes in the remaining 10*8 inch piece of cardboard, which were 1 inch apart and aligned with the placement of the cams along the axle. I then cut 4 more strips of cardboard, a 1*8, 2*8, 3*8, and 4*8 rectangle which would serve as the front of the stands. I glued each one on from the front of the 10*8 piece to the back in increasing order, right in front of each subsequent set of holes (which is pictured in the second picture above). The 10*8 piece with the stands glued on was then glued onto the top of the automata base with the axle and cams already in place. I then cut 4 more small strips of cardboard which were roughly 2 inches in length and 1/2 inch in width to serve as the base for the moving parts of the display. I glued pebbles along each edge to serve as weights, then two small straws which were held upright by both the glue and another pebble inside of it (shown in the 4th picture in this step). The straws were placed at such a distance so that they both hugged the inside edge of the two holes cut in the 10*8 top, meaning that the piece could not tip left or right. The straw set was slid underneath the top and up through the holes as shown above, and the process of straw cam base making was repeated 3 more times for each set of holes and each cam. Finally, I cut a 2*8, 3*8, 4*8, and 5*8 rectangle of cardboard out, and drew fans on each one of them. They were glued to the straw bases in subsequent order starting from the front of the automata and going back as the length of each piece increased. This way, they popped up and down enough to be seen, but the bottom part of each drawing was hidden, creating the illusion that the fans drawn on were actually moving up and down.

Step 5: Finished Product

The automata functions by rotating the wheel in front clockwise or counterclockwise. As it turns, it also turns the axle and cams with it. As the cams are not centered on the axle, they have edges that are closer and further away from the axle, which causes the displays mounted on top of them to raise and lower, depending on how tall the cam is at a given moment. Each cam is also mounted differently so that no display mount is in the same position at the same time. As the wheel turns, the displays bounce up and down, to create the illusion of life in the fans drawn on the front.