Our Trebuchet

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

Outline

Problem Definition Competition Performance Suggested Improvements Preliminary vs Final Preliminary Sketches Final Sketches Work In Progress Final Trebuchet Conclusion Acknowledgments

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Problem Definition

Intro: To design a trebuchet that will launch a Hacky Sack.

Constraints: Must fit into 4’x3’x2.5’ box and weigh as little as possible.

Objectives: To launch the Hacky Sack as far as possible, and with as much accuracy as possible.

Criteria: Must be “Homemade” and be launched from a distance of 10’.

Competition Performance

Our Trebuchet launched approximately 25’ during the competition.

Before competition it was launching on average 60’.

The change in it’s performance was due to the change in Hacky Sack weight and size.

The pin angle and size were unprecise.

Suggested Improvements

Use less 1”x2” in order to decrease the weight of the entire trebuchet

Make a permanent trigger once the ideal angle has been set

Practice with the ‘Official’ Hacky Sack Test more pouch sizes/shapes/materials at end

of sling Launch on a day with NO wind More extensive testing (sling length, pin angle,

and overall performance)

Preliminary vs. Final

Four triangles for support (two closer to arm and two on outside)

Maximize L5 (2.5’) Extend supports

completely in order to withstand the maximum force applied by the counterweight

Two large triangles w/ an addition two within those for support

Set the height at 2.4’ Decided to decrease

the width once we realized it’s lack of effect on the hurl distance

Preliminary Sketches

Final Sketches

Final Sketches Continued...

A Work in Progress...

The Final Product

Conclusion

In the end, our trebuchet complied with all the constraints/criteria (Dimensions and weight - our trebuchet only weighed 8.8lbs).

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.

Acknowledgements

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 Overall this was a fun and insightful

project.