This document provides a summary of Grace Hamann's design portfolio. It includes summaries of 8 projects: 1) EZ Composter, a self-aerating composter, 2) optimization of chimney fins for heat transfer, 3) redesign of seatbelts for increased comfort and safety, 4) balancing an inverted pendulum using feedback control, 5) testing carbon fiber composites for fatigue life, 6) a quadcopter drone for a competition, 7) a remote vehicle for nuclear facility inspection, and 8) a hybrid tricycle prototype. For each project, the document lists the design objectives, highlights of the solution developed, and diagrams or photos when relevant.

1. DESIGN PORTFOLIO
Grace Hamann

2. EZ Composter
EZ Composter was created in my university’s
Machine Design class as a response to the
prompt “design a functional product for a
current problem”.
I found that there were no composters on the
market that would self-aerate, while still
being exposed to the local environment and
its microorganisms. EZ Composter solves
this problem and more by;
• Being open to the ground
• Self aerating with an automatic auger
• Use of plate steel avoids weathering of
product

3. Thermal
Optimization of
Chimney Fins
The prompt for this project was to find the
maximum possible heat transfer from the chimney
stack to the surrounding air. The FEA package in
Solidworks was used to evaluate and select the
best chimney design. It was decided by the team
to make the chimney as efficient as possible,
while keeping the cost low. With these constraints
the following was determined;
• 1060 Aluminum Alloy selected for efficiency
and cost
• Optimum number of fins found to be 39
• Design achieved maximum flux of 26 Kw/m
Heat Flux of Fin
Temperature Gradient of Fin
Temperature Gradient of
Chimney

4. Advancing Seatbelt Design
Re-click it! was conceived in my Introduction to
Product Development class. The goal of the class
was to design a product and create a rapid
prototype. In my team we decided to focus on
redesigning the seat belt for increased comfort,
safety, and ease of use. After brainstorming
designs and interviewing our customer base we
came up with the following three design changes;
• Buckle Indicator; indicates when buckle is fully
engaged
• Buckle Base; Prevents
• Rolled Edge Seat Belt; increases comfort
without sacrificing safety

5. Buckle Base Prototype
Seat Belt Prototype
Buckle Indicator Prototype

6. Balancing an
Inverted
Pendulum
The objective of this project was to use control
theory to balance an inverted pendulum. The
system representation that was obtained was
then programed into LabVIEW to test the model.
Once the model was verified LabVIEW was used
again to run the electromechanical system. The
above was achieved by;
• Utilizing feedback control to stabilize the
system
• Analyzing the system’s root locus to select
gains that would give the ideal system
response
• Calculated system poles by using the state
space model and selected gains
Final System Model
Root Locus Used to Select System Gains
Free Body Diagram of System

7. Fatigue Testing
of Carbon Fiber
and Epoxy
Composites
This project was done in my Materials Science
class. In a team we designed, preformed, and
analyzed our chosen experiment. The objective
of this experiment was to test the fatigue life,
strength, and fracture toughness of carbon fiber
and epoxy composite samples with various
defects, in order to determine which defect was
the most catastrophic. It was found that;
• The composite’s fatigue life was large
relative to the sample’s cross sectional area
of .032 in
• Surface scratch had little effect on fatigue
life
• The sample with the edge crack led to most
catastrophic failures

8. Samples Before Testing

9. Pacific
Robotics
Quadcopter
This design was the Pacific Robotics' club’s
response to the ASME 2014 Lighter Than Air
UAV Student Design Competition. The objective
was to build a remote controlled UAV that could
pickup an object and drop it off in a designated
location, as well as fly through gates in an
obstacle course. It was also designed with the
required safety kill switch. Some of the
following highlights of this project are;
• Won 2nd place in regionals; 8th place in
international competition
• Could lift and fly with up to 1 KG
• Highly maneuverable

10. Pacific Robotics
Recovery
Vehicle
Pacific robotics participated in the Nuclear
Facility Remote Inspection Vehicle ASME
Design Competition. The objective of this
design competition was to design and build a
remote controlled, battery operated vehicle
that can complete the given course in less
than 5 minutes. It also was designed to pick
up and drop off objects and read facility
sensors. Some highlights of this project are;
• Dropped center wheels for ease of
maneuverability
• Raspberry Pi controller
• Remote controlled robotic arm

11. Hybrid Tricycle
For my University’s capstone class we were to
conceive of a product or product improvement
that is not already on the market and to create a
prototype of our design. Our team noticed a need
for a low cost personal transportation vehicle
using hybrid technology. Our objective was “To
design and fabricate a hybrid tricycle that is
powered by both an electric motor and gas
engine for maximum fuel economy.” With this
objective in mind we were able to create a
vehicle with;
• An efficiency of 18.5%
• Maximum Range of 42 miles
• Maximum speed of 27 Mph

12. SOLIDWORKS Drawing of Final Design
Engine support design in progressSOLIDWORKS Drawing of Shaft Assembly and Gearing
Manufacturing in Progress

13. Miscellaneous Design Sketches
In my free time I enjoy sketching ideas for products that pop into my head.
Design Ideas for a Satellite that Recycles Space debrisDesign Ideas for a Marine Motor that Mimics Jellyfish