1

TREDS

The Hard Boilers:Chris ChapmanMegan Kalend

See Vang

ENGR 5University of the Pacific

2

Overview

• Problem

• Approach

• Results

• Improvements

• Conclusions

• Acknowledgements

3

Problem

• Refugees inhabiting a region across a thirty-foot wide river are in need of eggs. These must be delivered across the rebel-patrolled waters.

4

Constraints

• Size requirements

• Timed delivery

• Range

• Target restrictions

• Egg delivered intact

• Cost efficiency

5

Approach

• Preliminary Ideas

• Refinement

• Analysis

• Implementation

• Testing

6

Preliminary Ideas

• Catapult or Trebuchet?– Pros– Cons

• EPU– Materials– Shape

7

Catapult Refinement

• Implemented elastic power source in place of counterweight– Pros

– Cons

8

EPU Refinement

• Material:

–Armaflex® rubber insulation

• Shape:

–Modified barbell

9

Analysis• Conservation of Energy

• Elastic Energy

elasticelastic KEPE

22

2

1

2

1initialmvkx

10

Analysis

• Projectile motion

ygvvinitialfinal yy 22

tgvvinitialfinal yy

tvxinitialx

11

Implementation

• Using Laws of Conservation

• Logical Estimation

• Preliminary Platform

12

Testing

• Trial Setup

13

Results

• Final design

• Competition performance

• Analysis

14

Successful Trial DataTrial Number

Radial Distance from Center (ft., in.)

1 0 ft. 1 in.

2 5 ft. 9 in.

3 3 ft. 1 in.

4 4 ft. 0 in.

5 4 ft. 0 in.

6 4 ft. 0 in.

7 4 ft. 4 in.

8 2 ft. 11 in.

9 5 ft. 1 in.

10 0 ft. 9 in.

11 5 ft. 4 in.

12 3 ft. 7 in.

13 0 ft. 6 in.

15

Future Improvements

• Time Constraints– Allow for scheduling problems and last-minute

system checks

• Optimization– Optimize system in each step of design and

construction process

• Efficiency– Solve glitches to create a more effective

TREDS.

16

Conclusions

• Constraints and Criteria• Final Design• Competition Performance• Improvements

• Any Questions???

17

Acknowledgements

• Mr. Jared Lash of Saint Mary’s High School

• Michael Kalend