1. Trebuchet Design Project Presentation Team H.E.D. Huy Nguyen | Edward Lau | Daniel Vizcaino Lab Section Tuesday 4-6 PM

2. Outline Background information Problem Definition Approach Results Improvements Conclusion

3. What is a Trebuchet? Treb"u*chet n.-A military engine used in the Middle Ages for throwing stones, etc. It acted by means of a great weight fastened to the short arm of a lever, which, being let fall, raised the end of the long arm with great velocity, hurling stones with much force. Source: dictionary.com

4. Define the Problem Step 1 of the design process is to purpose the need and define the problem. Purpose: Design and build a working trebuchet that will launch a 1oz Hack Sack®

5. Constraints As with any project there are constraints: Trebuchet must fit within a 4 x 3 x 2.5 foot container Operator must be 10ft to the side when launching No hazardous materials may be used

6. Objectives/Criteria The goal is to launch the 1oz Hack Sack® as far and accurate as possible The trebuchet must solely be powered by a 12lb counterweight Performance score= flight distance (m) - centerline offset distance (m) - 3x mass (kg) Trebuchet must be set up and ready to fire in under 60seconds

7. Approach Preliminary Ideas Design Construction Refinement Analysis Decision/Implementation

8. Preliminary Ideas & Sketch The base is made up of 2 3ft. Pieces of 2x2 wood separated by 2 1ft. Pieces of 2x2 Connect 2 2.5ft. Pieces of 2x2 wood vertically to the base The vertical pieces are centered The arm has a hole drilled through it where the dowel is inserted The dowel rests on grooves at the top of the vertical pieces All connections will be made with screws

9. Refinement Sketches The vertical pieces were removed a foot from the end of the trebuchet to maximize the sling arm Supports were added to the vertical pieces The base was changed from 3ft. to 4ft. long

10. Final Design

11. Final Design Sketch Supports were added to the side of the trebuchet that will be connected both to the base and the vertical pieces The dowel will be inserted into the vertical pieces instead of just resting on top of the pieces A hole will have to be drilled into the vertical pieces so that the dowel can be inserted The supports for the vertical pieces and the vertical pieces themselves will be attached to the base using carriage bolts

12. Results/Discussion Normal launch distance: 70ft. Official launch distance recorded: 59ft. Final Score: -1.31 Final Rank: 11 (1 st in lab section)

13. Improvements Lighter wood Wheels Better release mechanism Different support structure

14. Conclusion Using higher quality wood made the trebuchet more durable but added extra weight Weight and size were factors that should have been more thoroughly explored Launched a final distance of 59.0 ft The most important thing we learned was communication and teamwork

15. Acknowledgements We would like to thank: Professor Litton and Professor Golanbari for all the help Home Depot for materials Machine shop for letting us use it