By: Alexandro Perez Greg Desrosiers Laura Berg Tara Hodgetts

1.Problem Definition 2.Previous Design 3.Current Design 4.Performance Statistics 5.Performance Cont. 6.Performance Cont. 7.Design Improvements 8.Conclusion 9.Special Thanks

The main objective of this project was to design a trebuchet that, while using the most efficient design, that maximized its launch distance while minimized its weight. The size of each trebuchet, fully assembled shall be submitted 2 days prior to the competition. When fully assembled with the swing arm in a horizontal position, the entire trebuchet must fit within a 4 x 3 x 2.5 foot container. There is no weight restriction, only a penalty as stated above. The time needed to fully prepare the trebuchet prior to each hurl will be measured. Teams will be given 60 seconds to prepare their device; teams requiring more than 60 seconds of set-up time will be penalized 1 point per second. Each design team will select two operators who will be allowed to set up, load, and activate the trebuchet.

Our first design used lighter wood for the joints where a high amount of stress was present. Due to this the design failed. Further research was needed before the counterweight was added with a faulty release mechanism. This caused undue stress and the design failed.

Design Statistics Constructed of 2x2 pine wood Constructed of 2x2 pine wood Base dimensions: 3ft.x1ft. Base dimensions: 3ft.x1ft. Height: 2.5 ft. Height: 2.5 ft. Weight: 10.5 pounds Weight: 10.5 pounds Fastened with #6 6x1-1/2`` screws Fastened with #6 6x1-1/2`` screws

Possible changes in design 1.More accurate construction of joints. This will greatly reduce wobble and hence increase accuracy. 2.Use lighter wood where a high amount of stress is absent. 3.Move the axle forward hence optimizing the throwing arm lengths.

During the computer simulations, we found that our design should launch a hacky sack 62 feet. When we actually built the trebuchet and tested it, it launched 60 feet on the first trial and about 35 feet for every trial after that. There were significant differences because of wind. During the competition, we had to launch against very strong winds. This made the launch distance extremely short. For future trebuchet builders, we recommend researching what type of wood you are planning to use to build it. The lighter wood is best. Also, careful consideration must be used during construction because the designs may be very fragile do to their lightweight. This project showed how communication is crucial even for the smallest of projects. This gave us insight to the problems we may encounter in the engineering world and showed us many things we cannot learn from a textbook.

Special thanks to Professor Litton and Professor Golanbari, Professor Turpin,and all the people that woke up early in the morning to attend the launching. Also a really special thanks to Home Depot for being open at all the right times.