Final Blog Post: Semester Wrap Up

Team DC had quite an exciting competition day! As the photos above reveal, our team ended up coming in third. The victory was even better when they had a jumbo sized check to give us.

In the final week leading up to the competition, our team was able to get in a few practice runs on the table. Some of the last minute fixes we had were the creation of the red net, and then using the epoxy to finally secure the front gate.

The final machine, shown in the two pictures above, ended up being very similar to the sketch model created in the beginning of the semester. We ultimately decided to paint the machine red and black, as shown in the images. The front gate, which was driven by the planetary gear box, was made of acrylic. This piece could be rotated up and down to allow for balls on the table surface to be held inside the front corral of our machine. The rear of the machine was powered by the double gear box. The shafts were each supported by a pillow block and the machine side. Because our front wheels were fixed to the side walls, we knew that in order to turn we would have to slide the front. To help this issue, we actually used very fine grade sand paper and smoothed out all the imperfections of the front two wheels. Then,  on competition day, we greased the wheels to further reduce and friction. The black tower structure was made of .75” aluminum square tube stock. The tower then supported a net structure that was made of the spring steel, which we permanently deformed into the final shape, as well as the .25” threaded steel tube that we bent to shape. The top arms that knocked off the balls were made of the delrin plates on the laser cutter. The tower top was held under the size constraint by a piece of nylon string running to the rear axle. We tied slip knots on either end for adjustability.  Ultimately, the machine executed almost exactly as planned.

Ben, who drove the entire competition, had a few chances to practice before our seeding round. During the seeding, we managed to capture and deposit 168 grams. This included both red squash balls on the tower perches, both black squash balls on the tower perches, and four ping pong balls. After seeding was completed, we were ranked 2^nd overall.

During the competition, our machine performed exactly as planned. In every round, we successfully captured a red squash ball. Because our opponents machines were usually not capable of doing the same, we usually deposited the red ball and secured the win. In the final four, our machine really was tested. In our semi-final match with T-15, we were able to capture a red squash ball. However, T-15’s machine did the same thing and also got a black squash ball. After noticing this, we tried to make a comeback, but to no avail as T-15’s front wedges suspended our rear driving wheels.

In the consolation round, we had perhaps our greatest victory. After going out and capturing the red ball as planned, we proceeded to move to the goal. The opposing team, however, had successfully captured a black squash ball and was moving in to play defense. When near our goal, we were able to drop a ping pong ball, however, as we were about to drop the red squash ball, we were knocked off line by the other machine. Down by a squash ball, we had to fight for nearly a minute to deposit our already captured red squash ball. In dramatic fashion, after many attempts, we were able to deposit our red ball, but as a consequence ended up getting our machine stuck in our own goal. The opposing team, seeing they were then down, had 10seconds to score. In nail-biting fashion, the final seconds ticked away as the opposing team was inches from scoring another black squash ball. Upon culmination of the round, Team DC had an impressive celebratory high-five and the crowd went wild.