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REFERENCES • 2013 SolidWorks Help. Web. 2013.
• Volt Plastics. VOLT catalog 24. September 2009. 107-108. Web.
<http://www.voltplastics.com/pdf/VOLTCatalog24.pdf>
• Amber Plastics. Designers Guide to Rotational Moulding. 1-13. Web.
<http://www.amberplastics.co.uk/UserFiles/File/Rotational_Moulding_Design_Guide.pdf>
REFERENCES
ACKNOLEDGEMENT
Jason Costello & Tony Abrams at Canyon Coolers, Make-it
Manufacturing, Dr. Srinivas Kosaraju, Dr. Brent Nelson, Dr. John
Tester, and Dr. Timothy Becker.
ACKNOLEDGEMENT
Figure 2: Cooler Assembly in the Latched Position
Figure 3: Experimental Data
Figure 4: Current Cooler Data Compared to Simulated Performance of New Model
Engineering Design
DESIGN
All major components of the cooler assembly were designed in SolidWorks software. The assembly
consists of four part files: the lid, body, and two identical latches. All standard components of the cooler will
be acquired from existing manufacturers. All materials required for one unit are covered in the components
section. The body and lid of the cooler were designed for rotational molding, whereas the latch was
designed for injection molding. The CAD files were designed as blueprints for mold manufacturing. Each
mold functions as the hollow container that dictates geometry for the finished product. Outlined objectives,
manufacturability, and aesthetic finish were all carefully considered in each component of the final design.
DESIGN
40 QUART COOLER DESIGN Dirk Prather ~ Dominic Albano ~ Federico Martolini ~ Daniel Miller ~ Bander Almazroua
Department of Mechanical Engineering
Northern Arizona University, Flagstaff, AZ 86011
INTRODUCTION
Canyon Coolers is a small business located in Flagstaff, Arizona
that provides premium ice chests for its customers. The coolers
they sell feature a rotationally molded UV resistant HDPE (high
density polyurethane) shell injected with low thermal conductivity
polyethylene foam. The demand for these products is rapidly
expanding in the American market, creating increased competition
between the numerous distributors. Canyon Coolers is looking to
improve upon its existing designs in order to expand their business
and develop a prominent position in the market.
The challenge presented was to overhaul the existing 40 quart
model that is offered by Canyon Coolers. A number of models in
their current product line suffer from minor defects that result in an
intolerable profit loss. The 40 quart model was selected for
research and development because of its current design concerns
and its high demand in the premium cooler market. The goal of the
new design was to engineer features that accommodate a wide
range of use, while maintaining long term durability and the
competitive price point of the existing design.
INTRODUCTION
• OB
• MSRP of no more than $199.99
• Increased ice retention from existing model
• Body fits inside at least one existing model for shipping
• Dead weight of approximately 20 lbs.
• Well integrated features that resist impact stress
• Air and water tight construction
• Warp resistant in areas of high concern
• Two available lid positions:
• Open flat against a wall surface (secondary)
• Fully open and supported (primary)
• Improved latching mechanism
• Designed optimally for Roto-molding
• High reliability / affordable maintenance
OBJECTIVES
TESTING
Experimental:
For performance purposes,
temperature testing was
conducted on the existing 40 qt.
model. Eight T-type
thermocouples, configured
through a NI 9213 DAQ, were
affixed in strategic positions on
the inside and outside of the
cooler hull. 24 lbs. of ice were
placed inside the cooler initially
and temperature readings were
taken every 10 seconds until all
the ice had reached a liquid
state.
TESTING
Simulation:
SolidWorks Simulation Xpress
was utilized to map common
stress situations in the latch
design. Stress maps were
developed to indicate areas of
intense stress concentration.
The results helped shape the
latch as it progressed through
the design phase. The stress
map for the final design is
depicted in Figure 1.
TESTING
Figure 1: Von Mises Stress Map of Final Latch Design
Secondary Opening Position
• Opens flat against a wall
• Near vertical angle
• Uses friction to maintain angle
• Allows full use of webbing slots
Primary Opening Position
• Allows complete access of contents
• Uses critter-proofing as stopping point
• Integrated hinge with single closed pin
• Warp resistant ear spacing
Hinge Section View
• Details of secondary stop mechanism
• Details of primary stop mechanism
• Lid to body tolerance maintains seal
and provides rigidity
• Large fillet radii ensure consistency
Phantom Latch
• Improvement on existing design
• EPDM UV resistant rubber
• Ergonomic shape
• Easily Replaceable
• Backwards compatible to all existing
Canyon products
Floor Design
• Four insulation injection holes used
also as rubber feet inserts
• Warp resistant reinforcing
• Slide plates reduce stress on feet
and create ease of motion
• Minimizes heat transfer out bottom
Body Lip Features
• Fixed handle
• Dynamic rope handle guide channels
and knot recesses reduce cost
• Tie down webbing slot
• Critter-proofing surrounds lip
reducing chance of infiltration
0
5
10
15
20
25
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
Tem
pera
ture
(C
)
Time (days)
Temperature of Selected Walls 24 Pounds of Ice
Inside Bottom
Outside Bottom
Inside Back
Outside Back
Inside Side
Outside Side
Inside Top
Outside Top
Ambient
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
Hea
t T
ran
sfer
(W
)
Time (Days)
Current Model vs. New Design Heat Transfer 24 Pounds of Ice
Current Model Heat Transfer
New Design Heat Transfer
Heat transfer rates for both the existing and the new design are
shown in Figure 4. An analysis of the results from the temperature
experiment and the geometry of the two coolers revealed an
anticipated 29% reduction in theoretical heat transfer. These
results substantiate the predicted performance of the new cooler
design. The final step, reserved for the client, is to take the
proposed designs in to the manufacturing phase.
RESULTS
The results of the thermocouple testing are depicted in Figure 3.
Initially all thermocouples started at the ambient air temperature
until ice was added. At this point the readings from the sensors
recorded a sharp decrease in temperatures. Steady state was
reached at about six hours. This continued until all of the ice had
melted, occurring around the fourth day. These results provided
insight on heat transfer information which was vital to the design.
• COMPONENTS
• Two plastic handles
• Two feet of Nylon rope, ¼" D
• One drain plug
• Two 3/16” trifold Aluminum
rivets
• Two 3/16” Nylon shoulder
washers
• 72” of insulating foam gasket
• COMPONENTS
• Two plastic knobs (latch part)
• Two flat head screws
• Four rubber feet
• 26” steel rod ¼ “ D
• 17.9 lbs. of HDPE plastic
• 2.26 lbs. of Polyurethane
foam
• 0.07 lbs. EPDM rubber
COMPONENTS
Recommended