March Madness
We were busy bees in March. After our Mid-Grant Technical Review last month, we got constructive criticism. One of them was that we needed more statistics and data to back up our explanation of our invention. We found out that research was our Achilles heel. In order for it to become our strength, we had to take time learning fundamental ideas of researching. We got split into groups since there were multiple things we needed to research. We were broken up into: patents of other vacuum trains in other cities, regulations applied to our invention, current volume and type of garbage in the train stations, and finally, current vacuum system for NYC trains.
We began to test out the suction power of the 80/20 prototype. We made a chart that examined the weight, dimensions, and type of materials. Using this information, we also added that the 80/20 prototype successfully picked up the object. With the water bottle as one of our testing materials, we changed the amount of water in the bottle for each trial to test the maximum mass that the vacuum's suction power could pick up. Our results show it was able to pick up multiple materials of different shapes. However, it still lacked suction power. Our mentors suggested that one of the main sources for the lack of suction power was due to multiple gaps, which meant a lot of air was escaping out of the vacuum. Our mentor's suggestion was to add goop and gasket to cover the holes up. With the modification using the gasket and goop, we also covered up the holes with good old fashioned paper. Yet, it somehow weakens the suction power. We found other alternatives to covering the holes such as hot glue. Even though our mentors had suggested goop, we found hot glue to be more convenient and effective.
After realizing the design for the vacuum was not effective, we came up with another design. This meant that we had to start all over again. Compared with the old design, the new design allows the vacuum to be placed horizontally. Also, storage space will be attached to the back. The trash will be collected through a tube that will be directed into the storage compartment. The reason for the new design was because it was an easier implementation compared to the one we were doing and secondly, we know that this design works because it had already been tested with street cleaners. After fixing the new design, we started experimenting the suction power. We observed that the suction power was not strong enough to suck up crumbled paper. It took a lot of manipulation and aid with the tube before it eventually went into the storage. The major problem once again was air escaping from the gaps.
Sensors are another feature to our design. We researched ultrasonic (using sound to determine distance) and light sensors. We started assembled the light sensors. However, after the assembly, the light sensors were not working. With much testing and trial, we were able to get the light sensors to finally work. We then started moving towards the ultrasonic sensors. Again, we had trouble making it work but after much trial and error, we got the ultrasonic sensors to work.
Another issue we had to look at was how the trash collected would be disposed. With the new modified prototype, we were missing the component on how to dump the garbage into the dumpster. We had mentors from Con Edison come to school to help us. We gave them our original idea, which was using the motor to turn the door by spinning it. However, our mentors told us that even though this idea works, it was not the best because while it spins, the issue would be how to make it stop at a specific point. So our mentors came up with an idea using pneumatic cylinder (Bimba). The compression of air within the pneumatic cylinder would push and slide the doors. Thus, opening the doors on the side and letting the garbage fall out. Another idea from our mentors was using pistons and hinges. Depending on where we put the hinges, it would allow the garbage to fall in different gaps. We brought up the idea that our vacuum would be put on top of a flatbed train. We also found that one of our constraints was that the flatbed always has a knuckle used to connect other train cars. An idea to dump the garbage effectively without the knuckle (the bumper that connects it to another train car) blocking the way was to use one of the pneumatic cylinders to push the storage a bit further out of the flatbed train and then use another pneumatic cylinder and attach it on each side of the storage so that it can raise and tilt the trash out.
