1. Trebuchet Team Members: Linda Hib, Charlene Obille, Hanh Phan, James Santos Lab: Thursday 4 - 6 University of the Pacific School of Engineering and Computer Science December 4, 2003

2. Overview / Outline Research: Operation & Development Guideline & Theory Optimization & Safety Design: Design Simulations Sketches Construction: Building the trebuchet Competition Rank based on score not distance Report: Design Logs Final Sketches

3. Problem Definition

4. Introduction Our objective was to build a trebuchet that would launch a one ounce hacky sack with certain constraints The overall grade is based on the performance, analysis, and the implementation of the design

5. Constraints Dimensions: 2.5 ’ by 3 ’ by 4 ’ Weight: 10lbs, anything over is penalized Counterweight 12 pounds Sling & Counterweight Anchor Non - Metal Trigger 10 ’ from Trebuchet Must be safe Dowel Half-Inch minimum Hardwood

6. Objectives/Criteria Build a trebuchet Use java simulation Analyze results Graph data Modify Competition Time limit  Pickup  Setup  Launching in optimal conditions

7. Approach

8. L1 vs. Distance

9. Angle vs. Time

10. Preliminary Ideas Longer sling length Shorter counterweight anchor Swing arm with varied settings Wide base design Metal braces for support Trapezoid shaped sides

11. Sketches

12. Refinement Trapezoid sides -> Triangle Sides Shorter sling length Longer Anchor Added an angled nail for sling release Added ring to release sling for smooth release Added metal sling track

13. Analysis Energy Conservation: Dowel rotation (friction) Length of counterweight anchor Friction of release mechanism Length of sling

14. Decision / Implementation

15. Results / Discussion Performance: 43 ’ Negative 25 ’ due to weight.7 ’ Offset Weight 18 pounds Score: -12.1

16. Suggested Improvements Create a design that isn ’ t so wide. Use thinner cut wood. Multiple pre set release angles. Smoother dowel rotation.

17. Conclusion The main problem with the trebuchet was that it weighed a lot. The weight of the trebuchet lead to poor score results. Design revisions lead to a drastic change in final design

18. Special Thanks Tool and Workspace help: Wat Dhamawararam Buddhist Temple The Engineering Workshop Instructors: Professor Litton & Golanbari Influence: Poeun Hib Stores: Home Depot