1. BRIDGE AND ROV GROUP 4

2. Alex Paige Collin Palmer Sifat Syed Marc Hermann

3. OUR PLAN The design of the bridge was the most important so we started with that. Since triangles were the most stable figure, we tried to incorporate them as much as possible. We used trusses, which are basically a network of triangles. After we had the bridge design, we split up the team into two subgroups. Alex and Collin would work on the bridge and Marc and Sifat would work on the ROV. Whichever group would finish first, started on the PowerPoint.

4. OUR PROCESS The design process for our bridge started on Monday with the West Point virtual bridge building software. We experimented with different designs and discovered what worked and what didn’t. We found where there is tension on the bridge and where there is compression. After that, we started with trying to put our design on paper. When the architects came, their ideas influenced us to change our design to make it more stable. After two models, the first small, the second a little bit bigger, our design was unchanged and we started on our actual bridge.

5. THE PRINCIPLES Stress Analysis was a key part of designing the bridge. We needed to know which design and structure would support a robot and three bricks. Load dissipation was also a key part in both the bridge and the robot. The bridge needed to dissipate the stress to the ground. The robot needed to dissipate the weight of the bricks from the top platform to the bottom platform.

6. THE ROLE OF EACH TEAM MEMBER Alex Paige played a key part in the design of the bridge. He also helped build the bridge along with Collin. Collin Palmer also helped design the bridge, and built with Alex. Marc Hermann designed the robot with Sifat Syed and helped build it. He also programmed it. He also created this PowerPoint presentation. He completed some of the website also. Sifat added key parts to the design and built the robot along with Marc. Sifat and Marc worked on the website while Alex and Collin finished the bridge.

7. CHALLENGES AND SUCCESSES The first challenge was obviously finding a structure that would support the ROV and the load it is carrying. We succeeded by having a checkerboard pattern beneath the roadway, a full-size truss above the bridge, and a half-size truss below it. Our bases are rather large which helps to dissipate the forces to the ground. We put planks on the bases perpendicular to each other to increase strength. Another challenge was the requirement that the car had to drive in one lane and return in the other. This meant the car had to turn around. We realized it would be easier to make the car smaller then to make to make the bridge larger. By using four motors instead of two and thereby eliminating the gears, we shaved two inches off our width.

8. OUR OBSTACLES AND HOW WE OVERCOME THEM One major problem with the construction of the bridge was running out of planks. There were a couple obstacles in the design of the car. One of them was that the stilts for the second platform were misplaced, causing a slant in the platform. By relocating our transmitter to the underside of the second platform, we were able to make space for the stilts. The second was that the battery wire was not long enough to reach the brain. We turned it around, which solved that problem. Another constant and annoying problem was that the wheels would not stay on the car. The axles would keep sliding out of the motors. By using small bits of tape, we managed to buff up the axles to make them the proper size. Another problem that we found out about our robot was that once we put the three bricks, it would get stuck as we tried to tank steer left and right. Our solution was to turn and reverse repeatedly until we completed out turn.

9. IMPROVING THE PROJECT For the bridge, we could add more support for the platform over the bases. We also could of planned ahead to use all materials because we had some left over. An improvement to the robot could be finding a different way place to store the brain, battery pack, and transmitter. Another group (Group 5) had the idea of creating a vertical platform on which one side the brain was attached and on the other, the battery pack was attached. This would save space and eliminate the need for a second platform above the first.

10. LESSONS LEARNED When it comes to the bridge, gluing balsa wood stripes together strengthened the bridge against strain, stress, and compression. By putting planks perpendicular to the bridge, the structure was strengthened against bend. From the robot we learned that the the first prototype will not be the last. We had to try a couple different variations and fixes before we had our final product. We also learned not to overlook the small details. Small details (like the length of the battery wire) were overlooked and ended up costing lots of time to fix.

11. WHAT WOULD WE HAVE DONE DIFFERENTLY? Building the bridge on the simulator first would have helped of the design of the model. Alex would have brought gloves to the project because now his hands are blistered from hot glue burns. When it comes to the robot, if we knew then what we know now, we would have been done a lot earlier. Small mistakes ended up costing lots of time to fix. Also, we would have tried to integrate a vertical platform to store the robot’s components.

12. NOW, HERE’S A DEMO…

13. THANKS FOR YOUR ATTENTION !