This is the Team PB Ball Drop page; Team PB won the Ball Drop.
The Design Process
After receiving our materials, which included a rubber band, duct tape, a paper bag, a plastic bag, a paper sign, a foam tube, two skewers, and a tennis ball, we began brainstorming ideas. Many of our ideas involved apparatuses that would give the tennis ball potential energy, generally by way of the rubber band, so that the ball could still be released "from rest." The first idea was to use the rubber band to launch the tennis ball. The idea of a simple slingshot, possibly aided by a ramp or track made of the sign or skewers, came up. We also contemplated automated throwing arm and shotgun-like ideas. Momentarily, we contemplated making a balloon-motor out of the plastic bag, a bat out of the foam tube, and glider from the plastic bag. Another main idea that we discussed was creating a zipline, fundamentally made of tape. Though enchanting, we circled back to the idea of using the rubber band to project the ball forward. Upon the process of construction, we discussed various sling-shot methods, including setting the skewers into a base of foam with duct tape and launching the ball with the skewers as a ramp.
Construction and Redesign Process
The construction of our launching device started with finalizing our brainstorming. Our first course of action was to narrow down our list of options to the truly viable ideas. During construction, our first focus was on creating a piston-like launcher that would allow the ball to rest at the end of the pool noodle, through which we could use the rubber band to fire one of the sticks and impart momentum to the ball. Initially this was promising, as the stick could be launched separately, but when launching the ball, other issues arose: the stick did not always strike the ball directly, and the rubber band did not impart sufficient momentum to the stick and then to the ball, since the ball weighed significantly more than the stick individually. Our final launcher design was functional but not as effective as we would have liked.
We then considered another design: the zipline. We hypothesized that a zipline could deliver the tennis ball a further distance than the launcher, given the latter's constraints. There was no way to estimate accurately whether we had sufficient tape, but since the other design was complete, we decided to use the remaining resources in an attempt to create a functional zipline. We folded over the entire role of duct tape to make a track, and then cut that in half to achieve greater length. We used the empty duct tape roll, the string, and the paper bag to create a "harness" for the ball after determining that the duct tape roll minimized friction with the duct tape line (in comparison with string or the paper clip). Therefore we finalized the zipline idea and tried testing out immediately after construction. However, we encountered some difficulties testing out the zipline properly on that same day because of the wind so two of our group members volunteered to test it on another day where there was less environmental interference. These tests were ultimately successful, and that success has garnered victory!
Final Design & Result
The zipline was made of the duct tape we received. We cut the duct tape into fourths in order to increase the length of the zipline and then folded each fourth in half with the sticky side on the inside. The fourths were taped together with the remaining duct tape. The device carrying the tennis ball consisted of the cardboard roll that the tape had originally been rolled around, a piece of string that was looped and knotted around the roll, and a brown paper bag, which was attached to the other end of the string, that contained the tennis ball. The tape roll was then placed through the line of tape to form our zipline. On the day of the ball drop, the zipline carried the tennis ball 18.6 meters away from the bottom of Hicks Hall.
Backup Project: Launcher (not used in final ball drop)