1. Our Trebuchet Group: Adrian Hernandez, Randolph Noriega, Kristen Michaelis, and Shaan Barn Lab: Thurs 6-8pm

2. Outline n Problem Definition n Competition Performance n Suggested Improvements n Preliminary vs Final n Preliminary Sketches n Final Sketches n Work In Progress n Final Trebuchet n Conclusion n Acknowledgments n Slide 3 n Slide 4 n Slide 5 n Slide 6 n Slide 7 n Slide 8,9 n Slide 10 n Slide 11 n Slide 12 n Slide 13

3. Problem Definition n Intro: To design a trebuchet that will launch a Hacky Sack. n Constraints: Must fit into 4’x3’x2.5’ box and weigh as little as possible. n Objectives: To launch the Hacky Sack as far as possible, and with as much accuracy as possible. n Criteria: Must be “Homemade” and be launched from a distance of 10’.

4. Competition Performance n Our Trebuchet launched approximately 25’ during the competition. n Before competition it was launching on average 60’. n The change in it’s performance was due to the change in Hacky Sack weight and size. n The pin angle and size were unprecise.

5. Suggested Improvements n Use less 1”x2” in order to decrease the weight of the entire trebuchet n Make a permanent trigger once the ideal angle has been set n Practice with the ‘Official’ Hacky Sack n Test more pouch sizes/shapes/materials at end of sling n Launch on a day with NO wind n More extensive testing (sling length, pin angle, and overall performance)

6. Preliminary vs. Final n Four triangles for support (two closer to arm and two on outside) n Maximize L5 (2.5’) n Extend supports completely in order to withstand the maximum force applied by the counterweight n Two large triangles w/ an addition two within those for support n Set the height at 2.4’ n Decided to decrease the width once we realized it’s lack of effect on the hurl distance

7. Preliminary Sketches

8. Final Sketches

9. Final Sketches Continued...

10. A Work in Progress...

11. The Final Product

12. Conclusion n In the end, our trebuchet complied with all the constraints/criteria (Dimensions and weight - our trebuchet only weighed 8.8lbs). n During practice we were very happy with it’s performance, however it didn’t do so well in competition (Due to the change in Hacky Sacs). The improvement that would have helped most would have been to test it more extensively.

13. Acknowledgements n Thank You to…… –Professor Litton and Professor Golanbari –Arnulfo and Lucy Noriega for the use of their house, tools, and food –Other engineering students who helped us with some minor problems n Overall this was a fun and insightful project.