Team Special T
A.T.G (All Terrain Grill)
S. Ducko, E. Emmanoulopoulos, T. Goodman; D. Hopper; W. Lee
December 11, 2013
ME 455 Analytical Product Design
Fall 2013
Prof. D. Brei
ABSTRACT
This report presents a complete overview of the business objectives, product description, market
analysis, and financial planning and forecasting for the All-Terrain Grill (A.T.G.). Appended to
this report are the fully detailed sections for each of these four primary areas. Product definition
and market analysis includes research on the customer persona, current competition, and market
value. Concept development and down selection methods to reach the proposed A.T.G. concept
are outlined. Product design in its entirety is presented from development methods all the way
through proof of concept fabrication and validation. The final appendices details the financial
analysis of the initial investment costs, estimated profit model, and projected financial forecast.
Table of Contents
1.
2.
3.
4.
Business Objective……………………………………………………..
Product Description……………………………………………………
Market Analysis………………………………………………………..
Financial Plan…………………………………………………………..
3
4
5
7
Appendix A: Product Definition and Market Analysis…………………
Executive Summary: Product Definition…………………………………
1. Market Research Methods…………………………………………….
2. Persona/Scenario……………………………………………………….
3. Product Definition……………………………………………..............
4. Competition Analysis…………………………………….....................
5. Market Value Proposition……………………………………..............
9
10
11
13
14
17
19
Appendix B: Product Concept……………………………………............
Executive Summary: Product Concept…………………………………..
1. Conceptualization Methods……………………………………...........
2. Functional Decomposition……………………………………..............
3. Concept Tree……………………………………...................................
4. Top Concepts……………………………………...................................
5. Concepts Selection……………………………………..........................
6. Proposed Concept Description……………………………………......
20
21
22
23
25
28
31
33
Appendix C: Detailed Product Design……………………………………
Executive Summary: Detailed Product Design………………………….
1. Technical Development Methods……………………………………..
2. Parameter Analysis…………………………………….........................
3. Design for X…………………………………….....................................
a. Design for Manufacturing/Assembly…………………………
b. Design for Environment…………………………………….....
c. Design for Human (Aesthetics, Beauty, and Variability)……
d. Design for Testing……………………………………..............
4. Final Design……………………………………....................................
5. Manufacturing Plan…………………………………….......................
6. Proof of Concept…………………………………….............................
7. Validation……………………………………........................................
8. Design Recommendations……………………………………..............
35
36
38
40
47
48
48
50
53
53
56
86
109
111
Appendix D: Financial Analysis…………………………………………..
1. Cost Model…………………………………….......................................
2. Profit Model……………………………………....................................
3. Conjoint Analysis……………………………………...........................
4. Financial Forecast……………………………………..........................
114
116
118
120
122
Appendix E: Information Sources……………………………………......
126
2
BUSINESS OBJECTIVE
Some, perhaps even most people might look at the A.T.G. (All-Terrain Grill), especially in its
fully deployed state, and think to themselves “it looks like just another charcoal grill to me”.
This however is precisely where the old phrase “don’t judge a book by its cover” comes from.
The A.T.G. has the potential to fill a valuable market niche that is not currently being met.
The market for grills, both stationary and portable, is not “saturated”, but they both possess
plentiful and well established competition. This means that in order for a product to successfully
infiltrate the market it must have features that make it better than the existing competition at
satisfying a customer need. The A.T.G. is a product with the capability to do exactly this. There
are plenty of gigantic grills and BBQ’s out there with loaded a laundry list of fancy features and
gadgets and possessing the cooking capacity to roast a small pig. There are also a plethora of
portable grills available that are advertised as the ideal product for grilling on the go. Some
mobile grills even claim to be full size grills that can simply be broken down and taken with you.
This led to the question of, “What really constitutes the perfect grill for customers on the go?”
First off, what legitimately makes a device portable? Looking at the current portable grills on the
market, many not only lack in features that customers are used to from their large grill at home,
but they’re also not genuinely portable. Sure, almost all of them can be taken with the customer
everywhere they go, but most can’t be used everywhere. Many are small apparatuses that
require some sort of table to elevate them to a usable height. Models on the market that do
deploy and become stand-alone all require some sort of level ground in order to provide a level
cooking surface. These are two factors that limit true portability. A grill that can go anywhere
with a customer is only useful if they can also actually grill once they’re at their destination.
The A.T.G. is a product that efficiently solves this problem. It combines the full size cooking
capacity and the amenities of grills customers have on their back patio with the portability of the
current mobile grills on the market, all while being able to be used on nearly any surface. The
four legs of the A.T.G. (which conveniently fold flat for storage/transport) have inner sections
that telescope down and can lock independently at the desired height. Each leg has ten total
inches of adjustability to allow for level set-up on even the most extremely uneven of surfaces.
The leg locking/unlocking operates in pairs (left side and right side) and is actuated by a handle
that is nested inside tracks of the two primary carrying handles and is connected to tension cables
directly attached to the locks of each leg. This allows for full mechanism functionality with
minimal user input. In addition to this key element, the four hinges that the legs are attached to
also lock in the open (110⁰) and closed (0⁰, flush to the base of the kettle) positions.
The A.T.G. also possesses many other useful features that further increase its function and
desirability. Housed inside the bottom quarter of the kettle is an easy removal ash/drippings
drawer for quick clean-up of the mess made during the grilling process. Remove it using its
sturdy handle, dump the waste, and insert it back into the kettle. Side tables fold and lock in two
positions: open, to function as a place to set food, drinks, and seasonings during grilling, and
closed, to serve a secure top when the grill is stowed for transport. Underneath this top, inside
the kettle, the grill lid and cooking grate are stored safely from the elements. When cooking and
cleanup are finished simply pull on the same handles that control the leg locks and spring loaded
support pins will retract allowing the grate and lid to drop down into their stored location while
3
simultaneously releasing the legs. Allow the weight of the grill to return the legs to minimum
height, fold up all four legs, fold and lock the side tables and the A.T.G. is good to go!
PRODUCT DESCRIPTION
The mass manufactured concept for the A.T.G. is pictured below in figures 1 and 2 in both its
fully stowed and fully deployed forms. Aesthetically, the goal was to create a stowable, portable
grill that would resemble current stationary charcoal grills on the market when it was fully
deployed. Whereever the grill is in use the customer should feel like they are at home grilling on
a full-size, fully-outfitted piece of cooking equipment. The difference is that when the cooking is
finished, the A.T.G. is quick and painless to collapse into storage, toss into the car, and take to
the next venue. The real kicker is that this venue can be nearly any type of terrain. From loose
top soil to ground covered in dips and mounds, even planes of completely different heights, a
level, stable cooking surface can always be achieved. There’s also no skimping on the number of
friends that join. With over 341 square inches of cooking surface there will no burger left behind
and no man left hungry. The A.T.G. will transform any customer into a one man grilling
machine who can provide enough food to satisfy the entire party.
Figure 1: The A.T.G. in its fully stowed, transportable state
Figure 1 shows the A.T.G. in its fully stowed initial state. From this position the user would use
the carrying handles to transport the grill from their vehicle to the desired cooking location. The
first step is to set the grill down, unlock/open the side trays, remove the lid, and close the trays
back up. From here, lay the A.T.G. down on the back side of the kettle and move all the legs to
the open postion (where they will lock automatically). Once this is completed simply hold the
grill upright above the ground by the carrying handles and pull on the actuation handles, this will
deploy the telescoping legs. After the legs have released fully, use the weight of the grill to get
all for legs into the appropriate position to obtain a level cooking surface (do not release the
actuation handles during this period). After a level surface is achieved, release the actuation
handles and all four legs will securely lock into place. To finish the set-up, re-open the side
tables, pull out the drawer (which houses both the charcoal and cooking grates during transport)
and place the cooking grate on top of the support pins. Lastly, place the drawer back in the kettle
and the A.T.G. is ready for grilling! (This entire process should be able to be completed in less
4
than 1 minute.) When this process is competed the grill should resemble figure 2 (see next
page), with an obvious difference being the telescoping legs locked at various heights.
Figure 2: The A.T.G. in its fully depolyed position
With the A.T.G. is this position it is a fully functional lean mean grilling machine! Once the
cooking is done and the party is over, clean-up is a breeze. It’s even easier than the set-up as a
matter of fact. After using the drawer to dump all of the ash and food drippings, all the user has
to due is pull the actuation handles. This will drop the cooking grate and the grill lid down inside
the kettle (on top of the drawer and charcoal grate) as well as unlock and collapse all of the legs
to their minimum height. From here, leave the grill standing in the upright position and close and
the lock the side tables. Lastly, put the grill on its back side, unlock and all four legs and move
them to their closed position (where they will once again automatically lock). After this, the
A.T.G. is fully stowed and ready to be transported to the next grilling destination.
MARKET ANALYSIS
The unique features of the A.T.G. make it a product that could acquire mass appeal, however it
was designed with a specific customer sector as the primary target market. Customer feedback
was gathered from multiple surveys throughout the design process. The demographic of the
survey respondents turned out to be largely college age males, and the unity in the answers
across the board was overwhelmingly conclusive. Shown on the following page in figure 3 are
the results of responses to some key survey questions.
5
Figure 3: Key survey results used to determine consumer preferences and characteristics.
Q 8: For how many people do you cook?
Q 11. Where do you cook outdoors?
Q 24: Where do you live?
Q 1: How often do you cook outdoors?
These responses clearly indicate that the majority of consumers cook outdoors with relative
frequency and are cooking for groups of either 2 to 4 or 5 to 10 people over 91% of the time. It
can also be seen that over 75% of respondents live in either urban or suburban areas, but do
almost 86% of their outdoor cooking in public areas away from their home. From this it can be
directly inferred that a large majority of the time, consumers have a need for a product with large
cooking capacity that can be transported with them from their house to their destination. Delving
a little deeper and using some firsthand knowledge, many college students live in apartments or
housing without much surrounding property. This means that any grill owned would most likely
be stored inside the living quarters. Therefore the area of design focus was attempting to create
the optimal combination of portability and large cooking capacity. Portability in this case
meaning being able to efficiently store the grill at home as well as during transport and also
having the capability to use the grill as a stand-alone entity at any site the customer should so
choose. The product positioning chart shown in figure 4 depicts the target area of the market for
the A.T.G. in relation to what was deemed to be the top current portable grill competition.
Figure 4: Product position showing a need for a portable grill with large cooking capacity.
Portable
Inconvenient
6
The consumer surveys were created using Sawtooth Software. This software allowed for the
implementation of conjoint analysis. Conjoint analysis is a tool uses statistical comparison to
determine how consumers value different features of a product. This analysis enabled the
determination of the market preference for the A.T.G. using it’s the price, cooking capacity, and
storage size versus that of the top three competitors (same three in figure 4). Figure 5 below
displays these results.
Figure 5: Results of conjoint analysis simulation show consumers prefer the A.T.G. over the
Coleman RoadTrip and Kingsford Portable Charcoal Grill.
Conjoint Analysis Showing Market Share
From all of the above information it can clearly be seen that there is both a market niche and
customer demand for the A.T.G. With the necessary capital investment and the proper
marketing techniques the A.T.G. has the potential to be the most successful portable grill on the
market in the near future.
FINANCIAL PLAN
In order for any product to be deemed legitimately successful it must eventually generate a
profit. After thorough analysis, the potential market for the A.T.G. was found to not only be
existent, but also quite profitable. This conclusion was reached by creating a cost model of the
A.T.G., a profit model with market analysis, a conjoint analysis of the market and products to
further refine price, and a financial forecast to ensure that there will always be cash reserves.
The cost model was used to find the total cost to produce the A.T.G., breaking it down by each
part. Total cost of the grill was determined to be $60.52 including other costs such as sales,
marketing, and stocking. Manufacturing costs were determined by selecting the appropriate
methods such as sheet stamping and die casting for parts based on selection indices found in CES
with overhead being estimated in similar fashion, as well as labor rates based on current
statistics. The total manufacturing cost was found to be $14.98. Additional costs from sales,
marketing, distribution and general office overhead brought the grand total for production cost to
$86.82. Setting the sale price at $100, as determined through a variety of factors to be
appropriate, there will be ~15% profit per unit. Shown at the top of the next page in figure 6 is
the profitability chart for the A.T.G.
7
Figure 6: Profitability chart showing the initial investment for machinery, the annual
profit and net cash flow indicating a break-even point after 2.8 years
Break Even:
2.82 yrs.
Profit analysis began with a discounted cash flow analysis which examines the flow of money in
and out of a business and accounts for the discounted value of future earnings with an assumed
discount rate of 15%. The initial tooling, launch, and equipment costs were estimated to be
$517,000 (the red in figure 6) with an assumed launch cost of $100,000. An assumed tax rate of
37% was used. Additionally, production was assumed to increase by 5000 units each year
starting at 20,000 and ending at 40,000 (moving from 2% to 4% of the portable grill market).
The internal rate of return was determined to be 39.4%. Finally, it was found that the A.T.G.
enterprise will break even in 2.83 years, or the third quarter of the 2nd year and operate as a
profitable entity from this point forward.
8
APPENDIX A
Product Definition and Market Analysis
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EXECUTIVE SUMMARY
The first step of the design process begins with choosing a market sector and trying to define a
current problem within it. A hypothesis of interest is the starting point, but it must soon be
followed by market research that either aids in its validation or refutation. The sector chosen by
the group was outdoor grilling. The hypothesis was that customers had issues with forgetting,
misplacing, and/or losing equipment when attempting to cook outdoors and away from the
comfort of their own home. Market research conducted began with talking to potential
customers about their outdoor grilling experiences and problems, venturing to local stores to
view current grill/cookware inventory, and searching the internet for the wide variety of items
offered. A few items were found that at least partially solved what was believed to be the
potential problem. These items were centered on multi-functionality, compactness, and mobility.
These are all attributes that we felt would reduce the risk of losing or forgetting utensils or
cookware.
In order to fortify the hypothesis and obtain a legitimate problem statement for the final product
a survey was created and distributed to the potential customer base. The survey contained
questions ranging from as general as, “How often do you cook outdoors?” to as specific as
“What utensils and cooking method do you frequently use and/or prefer?” It was also desired to
know what people valued in their grills/cookware along with the problems they had experienced.
The end of the survey posed demographic questions such as age, gender, marital status, and
income level in order to pinpoint the ideal demographic to target. The results of the survey were
not quite as expected, but they did guide the way to a market sector with need. It was found that
almost no customers had issues with losing or forgetting cookware/utensils. However, it was
discovered that the customer base shared many characteristics which pointed out the clear
direction of a common need in the market.
Many of the customers said that they cooked out somewhere between a few times a year to a few
times a month, but that activity was heavily increased during the summer months, as might be
expected. Almost 75% of the customers surveyed stated they were single, but over 90% of the
feedback stated that cooking was typically done for either 2-4 or 5-10 people (about 45% each).
This means that people are gathering together to cookout. The setting that outdoor cooking most
frequently took place in was at a campsite or recreation area; however, 75% of customers
surveyed reported living in an urban or suburban setting. Therefore, customers are not only
coming together to cook outdoors, but they are also traveling to a common public place to do so.
The preferred method of cooking was charcoal or gas, totaling 78%. Putting all of the above
information together a new problem was discovered in our market. This problem is the lack of a
portable grill that combines full-size cooking capacity with the compactness to be easily
transported. This is a problem definitely has the potential be exploited and solved with the
introduction of a new product.
Full-size grills are typically heavy and/or bulky making them difficult to transport. Lots of
portable grills have features such as collapsible legs, wheels, and removable components.
However, there does not seem to be a grill on the market that allows for easy and convenient
transportation from a person’s home (in urban suburban areas) to recreational sites/campgrounds
(in predominately rural areas). The product currently being developed will look to fill the niche
of a grill that has full-size cooking capacity, but is also completely stow-able/deployable for
10
efficient transport, set-up, grilling, cleaning, teardown, and storage. The target location for
primary use will be wherever customers are away from their home while grilling. The customer
survey also provided desired requirements for the product to fulfill as a standalone entity, as well
as allowing the determination of measurable metrics for these attributes. The Quality Function
Deployment or “QFD” diagram shown later in this report gives the full breakdown of the
customer requirements, the metrics, and the internal relationships and trade-offs between them.
The top customer requirements are those that make-up the target market niche; large cooking
capacity and compactness (for portability) while being cost competitive. The QFD also
benchmarks what has been deemed to be the leading current market competition to the future
product. As the design process continues there will need to be deeper delving into the product
definition as well as continued product scope refinement.
MARKET RESEARCH
In order to find a problem, and define it well, it is best to talk to those most likely to experience
it. The user can provide powerful insight into their needs, problems, and wants. The group first
conducted basic research methods into market segments of interest. Once the market was
narrowed to the outdoors, with focus on cooking, the team took several steps to further gain
insight into the users by conducting market research. Methods used include a basic observation
of customers and asking simple questions, implementing a survey, and using empathetic methods
to better understand the situation. From these, design metrics were determined and listed below
in Table A.1, with their respective market research source(s).
Table A.1: Design metrics and the market research method(s) they were derived from.
Metric
User Interview Observation Empathy
Survey
Cooking Capacity
X
X
X
X
Weight
X
X
Compact Size
X
Inexpensive
X
X
Durable
X
X
X
Ease of use
X
Ease of cleaning
X
X
All Terrain Stability
X
Heat Resistant
X
Good Looking
X
X
Easy to Assemble
X
X
Safe to Use
X
X
X
Observations
We went to several environments in which potential customers might use or purchase the
equipment necessary to cook outdoors. Stores targeted were Walmart and Meijer for the lower to
middle income customer, and Cabela’s for the more enthusiastic sportsman or outdoors
enthusiast. We also spoke to potential users and found that customers want tools that they can
transport with them (mobility), relative affordability, durability and therefor value, ability to
clean easily, that are good looking, and made in the United States because many people
identified as patriotic. In addition, experts in the industry were consulted by asking salespeople
about customer trends, complaints and demographics. This was also conducted online.
11
Empathetic Methods
Several people attended cookouts and tailgating events to not only observe but also experience
the situation as the user. From this, it was found that tools for cooking would benefit from being
lightweight and easy to transport in a bag or truck, easy to clean with little access to water or
other solvents, able to withstand rain and other elements, resistant to direct flame, U.S. made to
support the patriotic user, and readily available either online or a big box retailer to ensure a
lower cost and greater convenience because the user wants to enjoy the outdoors at their leisure.
Survey
In order to further distinguish the potential user, their problems, and see if our problem in fact is
substantive and potential solutions we composed a set of online survey questions. While creating
the questions, we strived to remain impartial, and give the user clear questions that started broad
and then moved to more precise. Our demographic questions were added to better understand the
user and their background while being sensitive to their situation. Open ended questions were
provided to get a wider range of user feedback.
Key survey results are indicated in fig. A.1 below and referenced by question number. It was
found that most cook for a group of 2 to 10 people seen in Q 8 and do so at so at a recreation
area, Q11. Some key demographics indicate that the average user is a single male or female in
their early 20’s who is a recent college graduate or similar making around 25 thousand dollars a
year, living in an urban or suburban environment as seen below Q 23 and Q 24. The most
common season to cook is summer seen in Q 5, with most people cooking out a few times a year
seen in Q 1. Price, durability, and functionality were also found to be important aspects of a
cooking equipment.
Fig. A.1: Key survey questions and results used to determine customer preferences and
characteristics.
Q 8: For how many people do you cook?
Q 11. Where do you cook outdoors?
Q 24: Where do you live?
Q 23. What best describes your income level?
Q 5: During What seasons do you cook?
Q 1: How often do you cook outdoors?
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PERSONA/SCENARIO
The primary consumer for our product is Fred, a middle class individual, who is single, age 23.
Fred just graduated from college with a degree in Marketing and now resides in an urban setting,
near the beach in the Chicago land area.
Fred predominately cooks at summer cookouts with his two roommates for his group of five
friends, who all live relatively close by. He uses mostly charcoal at campgrounds or recreation
areas for their grilling. Fred also likes sports, television, and hanging out with friends and
generally enjoys outdoor recreation. This includes but is not limited to outdoor family BBQ’s,
outdoor parties or graduations, camping trips, hunting trips, fishing trips, sports tailgate parties
and block/house parties.
Fig. A.2: Fred with his fellow Alumni cooking outdoors
(thecollegejuice.com)
He has strong family values and traditions passed down from previous generations, such as
grilling secrets. He is proud to purchase a product that is “Made in America”. That said, Fred
owns a small vehicle handed down from his family, which restricts his ability to transport bulky
camping and cooking equipment.
Fig. A.3, A.4: Fred with grilling equipment.
(www.thefoodfather.com)
(www.vat19.com)
Fred is looking for a product that he will be proud to talk about and show off to his friends when
he invites them over for his cookout.
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PRODUCT DEFINITION
This section describes the product attributes our team selected after reviewing the customer
survey responses, and which represent the needs of our customer majority feedback.
Cooking Capacity: Our product must be able to fit approximately 8 quarter-pound burgers or be
able to handle a similar volume since most customers usually cook in/for groups of people.
Compact: The product should be relatively small. The measurable metric is, therefore, volume.
By small we mean it should either easily fit in a car/bag or be collapsible. The degree of mobility
is strongly affected by how compact it is.
Lightweight: The mass of our product should be low; it should not exceed 5 kg. Being compact
does not necessarily guarantee low density. Light materials may jeopardize durability.
Inexpensive: The product should be targeted to the average income user and will not be a
luxurious item. Its cost will be measured in US dollars; this could conflict with durability.
Durable: The product should not show any significant signs of wear and tear that could
jeopardize functionality for at least 5 years. If the customer has to change it every time they go
camping or cook outdoors, then they will avoid it. Of course, the product lifetime will strongly
depend on the target group, circumstances and frequency of use.
User-friendly: Our product will need to be mobile, since it targets the outdoors market. Its
handle should be easy to grip and should be made of material that acts as a heat insulator. The
degree of mobility can be defined by whether it is definitely going to be taken with depending on
the mode of transportation used based on further research.
Easy-to-clean: The product should have a coating that keeps food from sticking to it;
unfortunately this may be an issue when trying to keep costs low.
Weather-resistant: The product should be usable under different temperature and precipitation
conditions in all four seasons of the year and in different climates. This can be measured in
temperature and humidity change resistance; overlaps with heat resistance.
Readily available: The product needs to be obtained by the customer within 3-5 business days;
other; local inventory and delivery methods may conflict with the low price of the product.
Domestically/Locally sourced: The product should be produced in the US so that consumers
will choose it when trying to support domestic industry. It would be even better if the product is
produced locally in order to reduce delivery costs.
Aesthetically appealing: Many users choose products based on their aesthetics. For instance
two exact same technologies may compete through cool shapes that resemble animals etc. This
can be measured in proportions, colors and texture type; this attribute may conflict with price.
14
Heat resistant: Since the product is going to be used for cooking purposes, it needs to be able to
resist temperatures of 700 degrees Fahrenheit. This attribute will also enhance weather
resistance.
Ease/Absence of assembly: The product needs to be sold fully assembled.
Safe to stow/deploy: The product should not exceed a pinch factor in order to avoid lawsuits in
case of accidents. The precise value is yet to be determined.
All-terrain stability: The product must be stable on height variations of a maximum of 10”.
Analysis of Requirements and Competitor Products
The QFD table listed below in Fig. A.5 on page 15 was an excellent analysis tool for important
product attributes. It takes into account the end user, manufacturer, and other stakeholders as
well as uses market and competitor research to get an accurate picture of the market. The metrics
chosen come from the market research done and customer survey results. In the Table, the
importance of an issue is ranked from 1-9 with (9 being most highly correlated).
The numerical values assigned in the QFD to customer importance, manufacturing importance
and seller importance were assigned a weight-ranking from 1 to 12 based on importance (1 being
the most important). The customer importance was determined from market surveys and the
seller importance was based on conversations had with retail store employees in sporting and
recreational retail outlets. The manufacturing importance for the QFD was assigned based on
knowledge and experience the team has working in industry.
For the given problem no governmental regulations impose any restrictions to be considered.
However, product development is limited by the team’s main business design objective, which is
an investment cap of three hundred dollars for the concept development. The attributes that
differentiate the team’s solution from its competition are discussed in the top concepts section of
the report.
15
Target
#1 Kingsord Deluxe Charcoal
Grill
#2 Uniflame Gas Tailgating
Grill
#3 Coleman Roadtrip Gas Grill
N/A
N/A
N/A
0"
No
N/A
91%
Yes
N/A
N/A
N/A
0"
No
N/A
94%
Yes
4
4
7
Lightweight
3
9
4
3
2
1
Inexpensive
1
5
2
3
9
Durable
1
9
6
9
8
4
User-friendly
3
1
7
11
10
11
Easy-to-clean
8
10
12
8
All-terrain stability
9
7
11
10
Ease/Absences of assembly
10
5
1
2
Safe to stow/deploy
11
8
5
3
Aesthetically appealing
12
12
6
12
Heat resistant
9
1
1
1
16
1
3
3
3
1
8
9
10
11
12
3
3
1
3
3
3
9
9
3
9
9
1
3
9
1
9
Pinch factor less than X
X% of customers find it appealing
Withstand fuel temperatures up to X⁰F
#3 Coleman Roadtrip Gas Grill
7
#2 Uniflame Gas Tailgating Grill
6
#1 Kingsord Deluxe Charcoal Grill
3
700⁰F
3
1
Yes
3
5
Sold fully assembled
Correlations
>90%
9
4
Stable on height differences up to X"
QFD: House of Quality
73%
9
> X Pinch
factor
Compact
3
Less than X sec to clean (soap & water)
3
N/A
6
Sold fully
assembled
9
2
Set-up time less than X sec
1
No
6
Up to 10"
variation
2
0"
1
<5 min
3
N/A
9
<60 sec
9
N/A
Large cooking capacity
1
Survive X product tip overs
1
X tip overs
1
N/A
Retail cost less than $X dollars
5
1
<$75
9
$45.00
7
3
$89.00
1
3
$176.18
Weight less than X kg
1
Customer
Requirements
<20 kg
Column #
8.4 kg
9
16.8 kg
1
22.9 kg
Collapsed dimensions less than X*Y*Z cm
3
Weak
60x30x40
cm
9
92x33x56 99x25x46 64x43x48
cm
cm
cm
Can hold 16 burgers (4" round burger)
Strong
Moderate
16 burgers
1
14
burgers
Seller Importance
3
Weak
16
burgers
Manufaturer Importance
9
16
burgers
Customer Importance
Strong
Moderate
Functional
Requirements
Row #
Fig. A.5: QFD Analysis, Template from [A.4]
T e m pla t e by: C hris t o phe r B a t t le s
P ublis he d: A pril 23, 2010 P o s t e d in: DFSS
To o ls, Design & Engineering, QFD
Relationships
1
3
3
1
3
1
4
5
5
3
2
2
5
4
3
1
5
4
2
3
2
3
4
3
4
4
4
3
3
1
1
1
1
1
1
4
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4
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5
COMPETITION ANALYSIS
In order to assess our problem statement, and potential place for our solution we needed to
conduct rigorous research into existing products, how they’re made, product strengths and
weaknesses and potential market issues. From this we can identify market risks, important
aspects for a viable product and create a product position chart to identify the market gap.
Patent and In Store
Through the web, several patents were found for portable style grills. They were similar in nature
and function but different in methods of application. A portable grill consisting of metal panels
with slits constructed over an open flame with removable grill slits [9] by Weyandt is somewhat
crude in its design and still requires assembly. This would be cheap to produce but not appealing
to most customers. Another notable design was a stake with adjustable grilling grate similar to
test tube apparatus [8] by Walker is novel in its height adjustment and lack of many parts.
However the stake poses a danger in transport and the parts are not very compact. Local in store
research at locations such as Cabela’s, Walmart, and Meijer failed to yield a wide range of
portable grilling options. The reason for this could that with the change from summer to fall, the
inventory is turning over, which means grills would be taken off of the show floor because they
are out of season. To compensate for this possibility, all of the online retail was also checked.
This turned out to be beneficial because this is where formidable competitors were discovered.
Fig. A.6: Competitor products in order; #1Kingsford, #2 Uniflame, #3 Coleman
#1, Charcoal
#2, Propane
#3, Propane
Online Competitors
Of all the competition found there were three grills chosen that best represented the niche of the
target market. All three, pictured above in fig. A.6 have large cooking capacities (14-16 burgers)
and all are considered to be portable. Two use propane for heat and one uses charcoal; but since
heat source doesn’t rule out capacity or compactness they can all be considered legitimate
competition. The first model (1) is a “Kingsford Deluxe Portable 17in. Charcoal Grill”. The
cooking area is 240” sq., along with an 85” sq. warming rack and only weighs 8.4 kg, retailing
for $45. However this grill is not collapsible at all and it only stands 19” high. The next product
(2) is a “Uniflame 15,000 BTU Gas Tailgating Grill”. The cooking area of this grill is an
impressive 294” sq. and it also stands 39” high when erect. This grill is meant to be transported
across the ground using its collapsible scissor legs, with two of the feet being wheels. The grill
17
weighs 16.8 kg and is reasonably priced at $89, but more importantly it is very lengthy when
collapsed, making it awkward to pick up/carry and also difficult to store indoors. It also only
possesses a single burner to heat its large grate. This grill is pictured in fig. 6. The last of the top
tier competition (3) is a “Coleman RoadTrip 20,000-BTU 2 Burner Gas Grill”. This 285” sq.
cooking area is more than respectable and two independent burners are used to heat it. The lid,
side tables, legs, and drip pan are all detachable/removable; but this all requires substantial user
input. This grill is pricey at a minimum of $176 and is also quite heavy at 22.9 kg. These grills
all possess some favorable traits, but none combine the traits of the full market niche into one
complete device. Additional products researched but not included are references [1, 2, 4].
Analysis
From the products found, and by taking a look at their features we were able to find some market
opportunities. All the leading competition possess large cooking surface and this was a feature
that was of the utmost importance to almost every user surveyed. However, what none of the
competition possesses is a truly portable form that can be easily transported and then deployed to
full size once the cooking destination is reached. This is where there is market space to be filled
within the target group previously described (especially in warm climate during the summer
seasons). The survey results show that primary drivers of the market are cooking capacity and
price; but, there is also a third driver that can be concluded from combining multiple survey
results together. This driver is the ability to easily store and transport the grill. With undercutting
competitor price being a difficult area to devote product focus to, the key will be to stay in the
competitive price range while creating a product that is far more portable than those currently in
the market. Seen below in fig. A.7 is a product positioning chart that shows a very realistic
market opportunity.
Fig. A.7: Product position showing a need for a compact grill with large cooking capacity.
Portable
.
Inconvenient
18
MARKET VALUE PROPOSITION
The competition research and product positioning combined with the results of our market
research reveal the problem and segment of the market we aim to satisfy as apparent from a gap
in competing products, the typical target customer and producer needed to meet our goals.
Customer Segment
To be effective we have narrowed our focus down to specific target customer segments with the
main focus being on males in their twenties, who are recent college graduates and live in an
urban or suburban environment. These are individuals who like to be active in the outdoors and
are sociable. As a recent graduate the product needs to be inexpensive and provide the customer
with a good value by being durable. Because they will be cooking for a medium sized group of
friends, cooking capacity is essential, and this combined with the portability of such a product is
the main goal of our product. Current market competition exists from grills that are either overly
expensive, have a large cooking capacity but are bulky and hard to transport (Uniflame and
Coleman), or those that are middle of the road in terms of cooking size and compactness
(Kingsford). The team’s product will fill the void seen on pg.17 in fig. A.7 by being compact or
portable yet still retain the cooking capacity of a full size grill. As indicated from market value
research, this combination would be best suited to fit our target customer’s needs. The design
will require a producer who can provide metalworking and steel forming experience at a good
value. The product can then be offered at retail outlets and outdoors specialty stores in key areas.
As with entering any new market there will be some inherent risks that the team needs to
mitigate in order to develop a robust and successful product. In terms of the product, there is
significant safety risk. The use of burning hot coals or cooking is by itself a dangerous task, but
when using such a compact design it is possible that the grill will not necessarily be stable. If a
grill where to fall, collapse or burn an individual this would be unacceptable. Therefore, the team
has decided to focus on a stable design over a moderately uneven terrain, will have precautions
such as nonmetallic grip or handling surfaces, and will dissipate heat fast enough to not be a
danger when transported. Another risk is not being able to significantly distinguish the product
from the rest of the market which has been controlled by well-known firms. This can be
mitigated by creating a design that is very different and fulfils the target customer’s needs.
Problem Statement
From our research we have been able to refine our original problem statement to the following:
we aim to solve the problem of a lack of a portable grill that has a large cooking capacity with a
compact and easy to use design. From market research, and the QFD seen in pg. 8, there are set
metrics the team must accomplish to make a successful product. Most important to the consumer
is the cooking capacity because they will be with a group of friends, and a compact and
lightweight design that is safe and easy to set up because they want to store this at home and
bring to local parks. The grill should be stable and level on a varying terrain that might be
encountered. A reasonable price and a durable product are needed to provide value to the
customer. As with any tool in food preparation it should be easy to use, clean and be heat
resistant, because the cookout is only part of the greater overall experience. Lastly, the product
should be good looking so that it instills a sense of pride in the owner. With the aforementioned
product specifications satisfied, the target customer will be drawn to the team’s product.
19
APPENDIX B
Product Concept
20
EXECUTIVE SUMMARY
This phase of the design stage was dedicated to product concept development. The problem that
the product is aiming to solve is the need for a portable grill that has the capacity to cook for up
to ten people at a single time and can be easily transported by a single person from their home in
an urban/suburban setting to a recreation area. Therefore the attributes essential to the final grill
concept were that it needed to be completely stow-able/deployable (both the grill itself as well as
the support system) and house a grate with a large enough cooking capacity. On the basis of
safety and further product differentiation (from the current market) it was decided that the grill
would need to be able to be leveled on uneven terrain.
In order to bring about the best product design possible many conceptualization methods were
applied including brainstorming, sketching, a functional decomposition, concepts trees, and three
dimensional mock-ups. The combination of methods assured that the chosen product concept
was formed from an “all-encompassing” idea pool. Initially, brainstorming, sketches, and mockups were used to transform ideas from thought into potential design solutions. Other methods
were invoked at a later stage. The functional decomposition provided a way to break the grill
down into objectives that were required throughout the entire grilling process and helped open up
new design pathways. Operations ranged from original storage and transport, through set-up,
cooking, and cleaning, and finished with waste elimination, and stowage. Concepts trees were
generated for the three main functional aspects; grill heating element, grill stow and deployment,
and the grill support system. Through feasibility and go/no-go analysis the concept tree for the
heating element was eliminated and charcoal was deemed to be the superior choice. The tree for
grill stowing and deployment was divided into four main categories of flexible, rigid noncollapsing, rigid collapsing, and hybrid solutions. The tree for the grill support/leveling system
was divided first based on what would achieve the leveling; the grill itself or the support
mechanism. These branches were then further subdivided based on automation vs. user input.
Both of the trees were then filled down with an abundant variety of solutions.
Five concepts were generated from combinations of solutions from varying tree branches. This
was done to ensure concrete distinction among features including appearance, size, support type,
grill stowing/deploying, and overall function. The concepts were then entered into a down
selection matrix where a net score for each grill was determined. This was done through the use
of the QFD customer requirements coupled with scores given to each concept per requirement.
These scores were had a combined weight factor that encompassed customer, seller, and
manufacturer importance. The net scores were used to rank the concepts from best to worst.
From these five concepts the final concept was an alteration of one of the five that incorporated
superior features from two of the other concepts. The final proposed design concept used a
support leveling system consisting of four independent and fully adjustable telescoping legs to
allow for “all-terrain” variability. The legs will fold up flat under the kettle for storage and will
possess both quick release and automatic locking mechanisms. These will minimize user input
during deployment. The grill stowing/ deployment is accomplished using a rigid-non collapsing
structure. The lid and grate are stowed inside the kettle and there will be side trays that fold up
and lock, securing the system closed and ready for transport. There will be a handle on the kettle
for transport through carrying; and feasibility dependent, two of the hinges may also house
wheels for the capability to transport the grill in the same manner as a rolling suitcase.
21
CONCEPTUALIZATION METHODS
Several methods were used to come up with a wide range of products in order to find the best
solution to our customer’s problem including brainstorming, sketching, a concept tree, mock ups,
and functional decomposition.
Brainstorming
The first method that was used to generate concept ideas was brainstorming. This is a traditional
yet effective method. The main use was to get any and every idea that was floating around in
thought form out and on to paper. Initially brain storming was done individually to make sure no
ideas were inhibited by judgment of others. After individual brainstorming had taken place the
ideas were brought together for group discussion, and further brainstorming was done as a team.
Time was spent writing, talking, and writing some more. The goal was to leave no idea for a
grill, grill component, or even an included grill accessory off the table. References 1-10 were
used to get general concept ideas for mechanisms and other features.
Sketching
Sketching is a useful method to introduce immediately after brainstorming. The ideas generated
during brainstorming are sometimes difficult for others to follow or visualize from simple text
alone. Sketching was used to help bring clarification and life to verbal and textual concepts. This
also brought about the beginning of feasibility considerations. Seeing concepts pictured for the
first time shed light on how complicated, unrealistic, or even too simplistic different designs
could be. The combination of similar designs and compatible concepts was also done at this time
through creation of further hybrid sketches. At the end of this stage there were a few good ideas
for potential grill designs.
Concept Tree
Created and used in conjunction with the functional decomposition were some concept trees.
Rather than one tree for the entirety of the grill, two separate trees were created, one for the grill
support system and one for the grill stow/deployment system. This is the conceptualization
method that served in some radical new concept generation. Being forced to come up with
functional achievements through “opposing” methods led to a plethora of ideas by the time the
bottom of the trees were reached. Combining different branches from each of the two trees led
to even more concepts.
Mock-Ups
The last conceptualization method used were some simple concept mock-ups. These weren’t on
the level of alpha prototypes, but rather more low level 3-D models using components such as
scrap paper, tape, pencils, and other miscellaneous supplies. These were used to try to get a
better comparison between models that seemed favorable after other conceptualization methods
had been used.
Functional Decomposition
Functional decomposition is a systems level approach to design that seeks to isolate certain
necessary actions or functions into their most basic components in an attempt to deal with
complex interactions. This is accomplished by drawing the individual functions needed to
22
achieve the overall task into segments, which include the name of the part and action being
performed on it. Into and out of the box can flow material as a solid and dark line, energy such as
electrical or mechanical as a thin line, and a signal as a dashed line. Therefore, each box has
inputs and outputs and the law of conservation of energy and matter must be adhered to.
FUNCTIONAL DECOMPOSITION
The functional decomposition for the portable grill is seen on pg. 23 in fig. B.1. The grill will
start off stored most likely at the owner’s house. Therefore it will need to be transported to the
outdoors for use. Once arrived, the user will have to operate the grill to deploy it, and this should
be secure from motions like vibration or gravity, such as being locked at a set height. Then the
cooking surface must be supported and level. All of these actions require energy input for which
there will mostly be frictional losses. Now heat must be generated by some means which will
require mass in to produce heat with heat losses. The heat must be applied to the food requiring
food in, the heat generated, with more losses of heat to the surroundings but resulting in cooked
food. There needs to be a mechanism to control the heat, such as flame temperature or grill air
temperature, which will take air in but also lose heat and produce waste. These wastes will need
to be disposed of somehow, requiring energy. Then once the grill is no longer in use and cooled
down, it will need to be stowed for transport and storage, again requiring energy with losses.
23
24
Fig. B.1
1B.:
CONCEPT TREE
Creating a concept tree for a collapsible, freestanding, self-leveling portable grill was an intricate
process. The approach was to create the tree based on the grill’s functions rather than its
features. Listing features does help with the conceptualization process, but there are so many
(possible) features in a device such as portable grill that the tree turns into a random and
seemingly infinite list instead of a narrowing hierarchy of design possibilities. The main
functional components of the grill are its heating element, its stowing/deployment mechanism,
and its support system/leveling mechanism. After a few trials it was found that rather than one
large tree, three individual trees (one for each main function) were more suitable.
The first function examined was the heat source. With portability being of vast importance, the
source needed to be mobile, yet effective. There are many energy sources that can create heat,
but singling out charcoal as the top choice for our portable grill was not very difficult. It is a
mobile, readily available, time tested, and affordable source of heat for cooking. After creating
and examining a list of other heat sources, they simply could not measure up to charcoal. For
example electricity requires a plug, wood requires large quantity and volume, solar or battery
power could not provide enough energy, and nuclear power is just unsafe. The only energy
source that was even feasible was propane. It is actually a more common fuel source for portable
grills in today’s market; but the key eliminating factors for our design were the added weight,
volume, complexity, and safety issues that a propane heating element brings.
Concept Tree #1, seen on pg. 25 in fig. B.2 displays the options for the support/leveling system
of the grill. The pros and cons of this tree stem mainly from a feasibility standpoint. Aspects
such as cost, practicality, weight, and engineering complexity are all key factors that were scaled
against achieving genuine “all-terrain leveling” vs. “height-adjustable leveling”. The ideal
scenario was to create a mechanism that was simple enough to be designed and manufactured
cost-effectively while providing leveling in all three dimensions.
The grill stowing/deployment mechanism possibilities are shown in Concept Tree #2 on pg. 26
fig. B.3. There are many ways to make an item compact for storage, each with its own pros and
cons. A stackable or foldable system could allow for a completed set up that resembles current
grills on the market. This is both a pro and a con in the sense that familiarity could attract
customers and give them vote of confidence to the product’s successful functioning; however, it
could also deter them from purchasing a product that may be “too similar”. The successful
design of a crushable or roll-able grill possesses the same good-cop/bad-cop feel. Either would
be a revolutionary emergence in the market, but they would also be difficult to enter the market
with and convince customers to spend their hard-earned money on.
25
26
Fig. B.2: Concept Tree #1 for grill support system. Highlighting indicated the selected design.
27
Fig. B.3: Concept Tree #2 for grill deployment system. Highlighting indicated the selected design.
TOP CONCEPTS
In order to meet customer demands of a portable, lightweight, adjustable grill that can cook for a
group of 2-10 people, we have generated concepts which we believe meet these. Below are the 5
most viable concepts that were chosen from the conceptualizations methods, functional
decomposition and concept tree described previously. These designs were chosen by group
consensus based on a wide range of the most realistic options that were deemed feasible to
construct while meeting user demands through an iterative process. This was assessed using a
table of pros and cons with final say left to engineering judgment. Some designs were preserved
beyond feasibility to provide a wider range of design alternatives. Their design and operation
will be discussed with images to help demonstrate functionality.
Concept 1: Stow-A-Leg
The first design seen below in fig. B.4 is composed of a rectangular charcoal kettle (A) that has
four sides that can fold over to lay nearly flat. Below the kettle base is a small recessed area. The
two side folding tables (B) would fold to cover this open area. On each of the side tables is a
locking mechanism (C), and two legs (D) that lie parallel to the surface and rotate to a full
vertical position with the tables folded out. These store compactly within the base of the
collapsed kettle. The rectangular lid (E) will serve as the storage box with the grate (F) in it,
tools, and the collapsed kettle and leg assembly. This will have handles to carry or be worn as a
backpack. The charcoal and debris will have to be removed by manually dumping prior to
folding the mechanism.
Fig. B.4: Rectangular collapsible kettle
with folding stow-able legs.
E
A
C
B
D
F
28
Concept 2: Portable Tire Grill (Hot Wheel)
The second design is seen on below in fig. B.5, and is composed of a wheel (A) and handle (B)
that breaks down into pieces in order to form a fixed height grill grate (C) on a single stand (D).
This stand would either utilize a base (E) or would just allow insertion in the ground in the case
of cooking on a soft surface such as grass (city park) or sand (beach). At its fully collapsed form,
the grill resembles a kid’s toy. It is composed of a wheel and a handle for the user to pull the
wheel back to their car from the cooking grounds. The wheel splits up into separate parts; the
charcoal container, the grate, a lid, and the base support. The handles are the supports for the
grill, either as stakes or the struts connecting the base to the kettle.
Fig. B.5: Rolling wheel with charcoal
canister and supports.
Fig. B.6: Backpack grill with
collapsing telescoping legs in the basin.
A
E
D
B
A
E
D
C
C
B
Concept 3: Backpack with Telescoping Legs (Port-a-grill)
The third design, seen above in fig. B.6 is composed of a rectangular box shape kettle (A)
supporting a rectangular grill grate (B) with telescoping legs (C) that can be lengthened and
shortened in three discrete increments and will fit into the corners of the kettle when stored. The
lid (D) which covers the top of the grill has straps (E) like a backpack, so that when the grill is
fully broken down, the kettle, grill grate and telescoping legs fit into the box and if the top of the
box is covered by the lid, it becomes a backpack. This aspect helps people carry it easily. In
addition, utensils and cooking tools are attached inside of the lid. The lid is also made of heat
insulating material so that people do not feel any heat and get burned while carrying it over their
29
shoulder. When grilling is done, the scoop shape tool attached inside of the lid could be used to
scoop and dump the leftover charcoal out of the box.
Concept 4: Folding legs (ORi-Grill-Me)
The fourth design is seen below in fig. B.7. The top half of the grill is composed of the
rectangular main grill body (A), which is where the cooking grate (B) rests on recessed pins
below the top plane. These are removable so the grate can be lowered and the lid (not pictured)
when flipped upside down will fit above the grate and below the plane of the top surface. The
grate will rest on a removable ash catching tray (C) at the bottom of the kettle that will be where
coals are placed when in use. Two side folding tables, (D) will be hinged to fold parallel to the
top plane of the grill and then will flip over the top surface and latch creating a cover to keep the
grate and lid in place. The lid will have a built-in thermometer and the base will have a small
level and handles on the shorter sides of the rectangular grate made of a temperature resistant
plastic. Each of the shorter sides will have a leg mechanism made of 2 bars (E) connected
together at the bottom with a base (F) by a pin joint within slots similar to exercise benches. This
mechanism will fold upon itself for storage where the base protrudes from the sides to allow for
carrying. Wheels can be added to the pin joint of one side to allow for the grill to be transported
like a wheeled backpack. There will be a locking/release mechanism to allow the legs to be
stowed safely and another mechanism to lock them in the fully extended position by supporting
the central knee joints of the linkage.
Fig. B.8: Rolling wheel with charcoal
canister and supports.
Fig. B.7: Rolling wheel with charcoal
canister and supports.
B
D
C
C
B
C
A
E
C
A
G
C
F
C
D
C
E
C
F
30
Concept 5: Pneumatic piston legs (JackD Up)
The fifth design, seen on page 29 in fig. B.8 has pneumatically actuated legs which deploy to the
user- desired height. The top half of the grill is composed of the kettle (A), which is where the
charcoal is placed. The grate (B) would rest on folding tabs within the kettle. The grate can be
lowered into the kettle and the lid (C) will cover the grill when in operation and latch to the
kettle when being transported. It has handles to allow for the grill to be carried. On each of the
shorter of the two sides of the kettle will be a support structure similar to a folding table. Two
telescoping legs (D) at each corner will connect to a fixed base (E) and pivot under the grill main
body for storage. A lever will release the locking pin to store them in that manner allowing them
to swing outward and down at an angle greater than 90 degrees for stability. Then the user can
pull another lever as lifting up the grill. This will serve to open a valve in a pneumatic gas
cartridge (F) at the center of each support mechanism. When puled, the user can lift the grill to
the desired height and level with ease. Releasing the handle will stop the motion. To collapse the
mechanism, the user again pulls this handle but this time pushes down on the grill to collapse it,
then pulls the other lever to fold it up and lock in place for transport. There will be wheels (G) at
the end without the levers, and the other short end of the grill will have a pulling handle to
facilitate transportation.
CONCEPT SELECTION
During the transition stage of the product development, the weakest concepts were excluded
using a down-selection pool. By taking into account the three-hundred dollar-budget, the parts
that already exist in the market, the duration until delivery, and the 3 weeks to build and test the
proof of concept for the design expo, the two ME Machine Shop supervisors were consulted in
order to determine the difficulty of fabricating potential designs. These steps concluded the
technology readiness assessment, and eventually a go/no-go screening, which also evaluated
artistic principles and marketability of the product. These methods were combined in order to
select the top five concepts for final consideration. From here, a more sophisticated process was
formulated in order to adopt the final design by developing a down-selection matrix, as seen in
fig. B.9 on pg. 31. This matrix utilizes the data from the QFD as well as both absolute and
relative comparison against the requirements needed to solve the market problem:
The top five concepts for the final design were #1 Stow-A-Leg, #2 Hotwheel, #3 Port-A-Grill, #4
Ori-Grill-Me, and #5 JackD Up. Individual ratings per criterion were assigned on a 1-5 scale
with 1,2,3,4,5 representing worst, worse, same, better, and best respectively. These ratings were
devised by choosing the best concept in that category, assigning a 3-rating and then assigning the
rest comparatively. The weight factors represent an average of customer, manufacturer and seller
importance according to the QFD. In the QFD, the ranking ranges from 1-12 with 1 being the
most important and 12 being the least. These are assigned based on information gathered through
surveys and manufacturing experience as explained in the Analysis of Requirements and
Competitor Products section of the Initial Hypothesis Market Testing and Evaluation for Gate
Review 1 appendix. The rankings have been normalized in this case by subtracting the ranking
from 12 and then averaging. Therefore, in fig. B.9, the highest weight factor is eventually given
to the criterion of greatest average importance. Then weighted scores per category are calculated
by multiplying the rating by the normalized weight. Finally, the net score for each concept was
derived by dividing the sum of the weighted scores per concept by the sum of the normalized
weight factors. The best score was then adopted and the next two highest concepts’ features were
31
also considered for incorporation into the winning concept, leading to the creation of a hybrid
with folding and telescoping legs. Despite certain advantages, Hotwheel and JackD Up were
eventually ruled out. Although the Hotwheel was to be particularly compact, inexpensive and
easy to use on variable terrain it was eliminated due to low cooking capacity, and even more
importantly due to its requirement of extensive user-input. The JackD Up concept was not
chosen because it would be very costly, heavy and hard to assemble despite requiring minimal
user input.
Fig. B.9: Down-selection matrix used to determine the selected concept.
Among the three concepts that were combined to form the final concept, the Stow-A-Leg
concept was not very user-friendly, or all-terrain stable but certainly was safe to stow and
deploy, while also meeting the lightweight requirement. Port-A-Grill, which was found to be the
best, is characterized by an overall satisfactory level (3-rating) for all criteria, with higher ratings
in the cases of user-friendliness, weight, stability and safety. Finally, the last concept whose
features were used for our hybrid, the Ori-Grill-Me, was heavy and lacked good stability but was
very favorable in design for assembly and aesthetics.
32
PROPOSED CONCEPT
With the aid of concept selection techniques such as down-selection and extensive discussion a
final design was able to be synthesized from three of the existing concepts, one, three, and four.
This ensured that only the best features of each feasible design were used to offer the customer
the most portable inexpensive grill with a full size cooking grate that can be made level on many
surfaces encountered by the user during the intended operation.
Fig. B.11: Photos of the prototype in the
fully deployed and stowed modes.
Fig. B.10: Drawing showing collapsible
tables, grate position, ash tray, and the
folding and telescoping legs.
Deployed
E
F
C
Top Sect.
A
D
B
Stowed
Bot. Sect.
G
B
DEVELOPMENT TEAM
Leg/ Kettle
Interface
The final design is seen above in fig. B.10 in conceptual drawing form and again in fig. B.11 as
photographs of the alpha prototype. This prototype serves both as a functionality and feasibility
check and also gives potential users or decision makers a better understanding in three
dimensions. From the grill concept tree, this follows the path of a rigid, non-collapsible design
with stacking grill elements and removable ash-dump drawer. Notice the top half of the grill is
composed of a rectangular kettle (A), which will have adjustable vents for airflow, an opening at
the bottom front and a built in level. Situated in this opening is the removable ash catch can (B)
which will also store the grill grate (C) when in the stored position and the charcoal during
cooking. The grate will rest on spring-loaded pins (D) on the shorter of the two sides and will be
slightly recessed below the top plane of the kettle. A lid (E) will rest over the crate and be
33
secured by the raised edge of the kettle while in use and stored in the kettle after the spring pins
are released and the grate falls into the ash tray. The lid will have a thermometer in it, a
temperature resistant handle, an adjustable opening to control flame temperature and space
underneath to secure tools. The folding side tables and supports (F) will extend to be parallel to
the top plane of the kettle when in use and provide space to store items. For storage, the tables
will fold over the now packed lid and sit flush with the kettle upper edges. A weather-strip will
be used to create a seal between the two and also prevent items from rolling off the tables or
debris from entering the kettle. A latching mechanism will keep the tables (doors) shut while in
motion. The grill itself will have handles on the shorter edges for carrying when in transport with
an optional wheel set on one end and extendable handle on the other. This comprises the top half
mechanism, which is its own subsystem and will interface with the supporting bottom section at
mounts to the kettle.
From the concept tree for the supports, the bottom half of the design is a telescoping mechanism
composed of four folding legs (G) with adjustable independent height and bar clamp style locks
to be actuated by a lever or other input with safety mechanism. In this case, the independent
supports provide the grill leveling. A pivot mechanism will lock the legs in the stored position as
well as at and beyond 90 degrees and will allow rigid rotation only in one plane. These legs will
store in a section below the kettle base and hidden from view by having the kettle exterior sheet
metal extend below the visible plane of the folded legs thus ensuring a safe and compact design.
34
APPENDIX C
Detailed Product Design
35
EXECUTIVE SUMMARY
The third phase of the design process focused on the creation of the complete design and
manufacturing plan for the proof of concept model of the All-Terrain Grill (A.T.G.). An alpha
prototype was created for the chosen concept, but this concept needed to be transformed from a
prototype into a fully functioning grill. When generating the A.T.G. there were key drivers that
influenced design decisions. These drivers were determined by looking at feedback from market
research, evaluating user interaction with the grill at multiple phases, and most importantly by
focusing on the safety of the product. It was found that the key design drivers for the A.T.G. are
the stability and strength of the telescoping legs/leg locks, the size and weight of the stowed grill
in relation to storage and transport, a large cooking capacity, proper heat distribution and
cooling, and lastly, minimal/simple user input for both deployment and stowing.
With these drivers in mind, design specifications were further refined. The first order of business
was to find a grate with large cooking capacity. The grate is the keystone component of the grill
because it (directly or indirectly) dictates the sizing of every other part. Grill grates are available
for purchase independently, and by making a quick trip to the local Lowes it was easy to
compare all makes and models. A steel 24.375 by 14 inch grate was chosen for the prototype to
give maximum cooking capacity while also coming close to achieving the golden shape ratio at a
relatively inexpensive price. A steel grate of this side would be self-manufactured for production
of the A.T.G. Next up was determining material type for the grill kettle, lid, and ash drawer.
Research was conducted on current charcoal grills in the market to find out what material type
and thickness is currently successfully being used in industry. Sixteen-gauge steel was found to
be the most common material used to construct the kettle/lid. The material properties of this steel
were then analyzed and compared to alternatives using CES EduPack 13 to be sure it was the
best option to meet the needs of the A.T.G. This evaluation found steel to be the most
appropriate material based on its properties of melting temperature, yield strength, fracture
toughness, and hardness. Looking to work with a local supplier to save time, Alro Steel was
discovered. They are located in Ann Arbor and have the ability to supply and cut the steel to the
desired dimensions. Keeping with the mentality of using components that were both cost and
time efficient, McMaster Carr was looked in to. Here the design team was able to find and
compare (pre manufactured) telescoping tubing along with all types of hinges, handles and other
assorted components needed to build the A.T.G. proof of concept. McMaster Carr has been a
successful supplier in the past and always provides efficient shipping of very high quality
parts/materials. All hardware for the mass manufactured model will be purchased from bulk
suppliers along with the steel tubing to construct the telescoping legs. The specifics of all
components to be ordered/manufactured were established by applying basic engineering
principles (static force and moment analysis) and FMEA analysis. These calculations along with
comparison tables of cost, availability, material properties, etc. are thoroughly explained in a
later section of this report.
There were many facets that needed to be carefully analyzed when designing the A.T.G. Not
only does the grill need to be designed for cost effective, efficient production; but, designing for
aspects such as manufacturability, the environment, human interaction, and testing also have
very important roles to play. The A.T.G. was designed with ease of manufacturing and assembly
in mind. If this product were launched, the goal would be to have to it be both manufactured and
assembled in house. This means that the only tasks the customer would have to carry out are
36
going to the store, purchasing the grill, taking it out of the box, and throwing on some burgers.
Components were designed to be simple and intuitive, with shapes that are aesthetically pleasing
yet quickly manufacturable. There is also a need to be able to thoroughly test a product before
putting it out in the field. It has to be verified that the product functions properly, has no major
safety concerns, and can withstand the use (and even misuse) it will be put through. Designing a
product that can be appropriately tested is a key feature that are often overlooked. Another
element that sometimes flies under the radar of design engineers is product image and real world
impact. With a general movement toward “greener” living sweeping today’s society, a lot of
consideration was given to the complete lifecycle of the product. From manufacturing and
shipment to customer use and eventual disposal, the A.T.G. was designed to have a very small
environmental footprint. Trying to eliminate waste, remove power intensive production process,
and use eco-friendly shipping procedures are all aspects that were incorporated into the A.T.G.’s
design. All that being said, at the end of the day a consumer has to be willing to trade in their
hard earned money in exchange for this product. That means that designing the grill for its user
is of the utmost importance. The size, shape, weight, and aesthetics of the A.T.G. were all
designed with the end user in mind. The grill should be affordable, durable, easy to
use/clean/transport, and should inspire some sort of happiness in the user during all phases of its
use. The grill also has to be attractive as that is the first feature that will draw a user in when
they’re surveying the available products on the market. Kansei engineering was used to
determine user preferences and develop the “look and feel” elements of the A.T.G.
Bringing all of this together, the final proof of concept design for the A.T.G. was created. The
grill kettle and lid will be made of 16-gauge steel and the legs will be fabricated from telescoping
steel tubing. The foldable side trays that double as a lid when closed will be made from
aluminum and be supported by padded bump stops. The legs will attach to hinges that lock in
both the open and closed positions, and will be 10 degrees past parallel when deployed in order
to increase stability. The telescoping legs will lock using a spring and tension cable mechanism
that functions similar to that of a bar clamp. The ash drawer will house an identical grate to that
of the cooking surface, but this will be used to place the charcoal on. There will be vents in the
kettle to provide airflow to the coal and increase efficiency. The cooking grate will sit on top of
quick release support pins that will be operated using the same handle that releases the leg lock.
This all will work together to allow the user to simply pull on the two handles, collapse the legs,
drop the grate as well as the lid down inside the kettle, fold up and lock the side trays and the
legs into their stowed positions, and hit the road. A complete manufacturing plan with
engineering drawings, a bill of materials with pricing and part numbers, and a set of assembly
instructions completed with exploded views are also included.
37
TECHNICAL DEVELOPMENT METHODS
When designing the A.T.G. (All-Terrain Grill) there were some key features that acted as the
drivers behind the proof of concept/final design. These drivers were the aspects of the grill that
had the capability to “make or break” the design. Failure to achieve success for any of these
drivers has the potential to result in product failure, severe ineffectiveness, customer injury, or all
of the above. Detailed analysis of this technical development method is described below and
seen in fig. C.1 on pg. 38 in a convenient table format.
Strength and Stability
The first key design driver is the strength of the deployed legs and their locking mechanisms. If
the legs collapse or the locking mechanisms give way, the grill will tip over hot charcoal will
spill. This is obviously a severe injury risk to the customer. Using SolidWorks a failure model
was developed for a fully extended, locked leg to determine the minimum requirements needed
to ensure support under the vertically downward load of an average male.
Similarly, stability of the overall deployed grill is also key. Someone hitting, pushing, or
running into the grill could cause it to tip over, resulting in the same spilling of hot charcoal. A
comparable failure model was created with SolidWorks, and free body diagrams, and the angle
of legs /height of legs was optimized for maximum stability while remaining within the target
height range for the grilling surface.
Portability and Cooking Capacity
Through customer survey it was determined that portability of the grill was very important. The
A.T.G. will be designed so that when stowed, its cubic volume will be less than the QFD
determined maximum requirements. This was efficiently modeled and measured in SolidWorks,
but will also be physically tested on the proof of concept. The only design driver as important to
customers as portability was cooking capacity. Grate size was chosen to maximize cooking area
while focusing on keeping the volume within the required dimensions. This driver was able to
modeled and verified in SolidWorks and will once again be tested on the proof of concept.
These parameters were considered drivers because the size of the grate directly affected the rest
of the grills components and altered mass, force, and part structure.
Grill Transport and Leg Deployment
It was also found through survey that the majority of potential customers were recent college
graduates who were living alone. Therefore, the grill needs to be able to be easily transported by
a single individual. The mass and volume of the grill that was chosen based on optimization of
previous design drivers was obtained through SolidWorks modeling and then compared against
the average size/strength of a young adult male. Grill specifications were then further altered and
optimized for transport.
Due to the fact that this grill will be frequently transported, deployed, stowed, and transported
again, leg deployment is an important property of the grill. The goal was to have the legs deploy
and stow with minimum user input and minimum chance for failure. A simple bar clamp style
locking mechanism actuated by a tension cord on a pull handle was chosen as the method to
produce leg locking and unlocked for deployment.
38
39
Fig. C.1: Table summarizing 6 design drivers with importance, development and validation methods for each.
PARAMETER ANALYSIS
In order to develop the most effective design while meeting the specified parameters, analysis
was completed in terms of the dimensions of the grill, specifically the legs, grate, and locking
mechanism were of importance. Material selection was done using CES software, in combination
with competition research. With parts designs verified, suppliers were scrutinized for the best
available options. Then analysis of the forces and loads seen by the grill was completed
assuming static loads. Additional analysis was completed using Solidworks to determine the
loads on the side trays treated as cantilever beams.
Material & Shape
The detailed design for the mass manufactured A.T.G. was developed on the basis of
maximizing assembly time and efficiency, while aiming to diminish the number of parts and
material and processing costs. Key drivers in material and shape selection were the predicted
economic batch size, which dictates the manufacturing processes that are most appropriate, as
well as the function of each subsystem and durability constraints.
Grill Grate: The dimensions of the grate are 24.375x14in, it is made of plated steel, and it is
supplied by Lowes. This supplier was chosen because store pickup will be the fastest and
cheapest way to get the grate on time. The alternative option was Amazon prime and McMaster
Carr with a delivery time of approximately 48 hours. These are used for other parts but since the
grate is key it is best that it arrives first. The dimensions of the upper body then depend on the
grate with an area a little larger than the grate so that the grate rests on four side pins, while the
height of the grill was selected to be 8in based on the QFD, which can be found in the problem
definition and market research section of this report. The grate size was selected on the basis of
the customer-induced requirement of cooking capacity of 20 burgers. An average 1/4lbs. burger
was estimated to have a 4.5inch-diameter. This dictated the area and shape of the grate. Another
engineering driver in the grate design process was the material that needed to be used for the
mass manufactured All-Terrain Grill. Using CES EduPack and the heat-resistant function and
temperature and load constraints, plated steel was selected as the most appropriate material given
cost limitations.
Side tables: Additionally, the side tables needed to fold and close the grill top like a box.
Therefore, the side tables were designed to be 12x14in. Finally, the lid size was chosen in such a
way that it can be stored inside the grill in its fully stored position. That requirement in itself
dictated that the body be 8 inches in height.
Grill Kettle & Legs: The shape of the kettle was essentially dictated by the square shape of the
grate; therefore, the golden proportion in dimensions and the shape of the top half were driven by
functionality and manufacturability. Design for humans dictated the dimensions of the four
support legs, as explained in the Design for X section of the report. The legs have to be long and
narrow in order to allow the necessary stability, as well as comfort for the average user. As a
result, the legs had to be 25 inches long, because this configuration allows the grill grate to be
32.6” off the ground, which is high enough so that the user will not need to bend over given the
average length of cooking utensils which is usually about 6” to a foot. In order to satisfy the
deployment requirement, each foot was chosen to constitute of two parts, of 13in and 12in long.
40
The reasoning behind the one inch length difference is that the folding hinge is bolted onto the
longer leg as a way of expediting the production process. The 13” maximum length aside from
the comfortable height for the user, also allows for efficient stowing. In the stowing position, the
legs will be situated along the kettle bottom diameter. By employing the Pythagoras Theorem,
the diameter will be approximately 28.5” long which limits the maximum length to 14” per leg.
However, because the upper leg is not attached at the very edge of the folding hinge, and as a
precaution to manufacturing inaccuracy, the legs are 13” in length each.
The legs were chosen to be square in order to be attachable to the leg folding hinges, simplify the
manufacturability of the actual lock clamp, and in order to appeal to the user aesthetically, which
in this case means it needed to appear more masculine. Although round tubing is typically about
20% lighter for the same overall cross section, square tubing is stiffer. Additionally, square
tubing is easier to cut and weld, especially for complex angle joints. Considering how round and
square tubing compares in the aspects of bending and compression load, if the round tube is
estimated to be approximately 75% of the weight of the square tube, and taking aluminum as an
example, square tube 36” long and ¾” * 0.065” would support 1100 lbs., while round tube would
only support about 650 lbs. For the mass manufactured product, the tubing will be produced in
house so production cycle time and cost per unit needs to be minimized. For the proof-of-concept
the square solid light duty telescoping-tube framing was selected.
Fig. B.2: Telescoping Leg Selection Matrix
Solid Light Duty Telescoping-Tube Framing
Heavy Duty Telescoping-Tube Framing
Round
Square
Perforated
Solid
¾” ; 2ft long
¾” ; 2ft long
1¾” ; 4ft long
1¾” ; 4ft long
$3.51
$4.61
$19.89
$19.57
Parts & Suppliers
Based on the parts required and their availability by each supplier, Amazon was eliminated from
the down-selection due to limited variety and stock. The remaining suppliers considered were
McMaster Carr, Alro Steel and Lowes. McMaster Carr was selected due to its extensive variety
and due to the Mechanical Engineering Department’s cooperation with them. Then for certain
materials, Alro Steel and Lowes were chosen because they are local and parts can be purchased
immediately. The most important factor in choosing the best suppliers was not speed of delivery,
however, but rather reliability. A competitive supplier website called Ali Baba was eliminated
due to unreliability of delivery date and the quality of the supplied parts.
A key part that allows for this design to be stable is the set of 4 hinges with locking tabs. This
ensures that the legs will lock at exactly 20 degrees past the perpendicular to guarantee stability.
As a result of this design, the forces exerted downward and laterally on the grill have the same
effect on the grill as if the legs-grill connection were rigid. The parts that were considered were
41
all supplied by McMaster Carr; the design of the folding leg bracket that prevailed was made for
square legs and locks in place; competing parts are presented below in fig. B.3.
Fig. B.3: Folding Hinge Selection Matrix
Folding Leg Bracket for Square Legs
Folding Leg Brackets
Item
Length
Load Capacity
Cost
2 1/2", 1 1/2"
75 lbs.
$5.72
1 5/8", 1 5/8"
Not rated
$5.05
Additional Material Selection Considerations
Material selection was conducted using CES EduPack 2013 software. This software allows for
selection of materials based on different criteria, such as density, price, carbon footprint,
mechanical, thermal and processing properties. After dimensions, shape and suppliers were
selected, those properties were considered in order to select the most appropriate solution
between stainless steel and aluminum for the core and legs of the grill, and between wood and
plastic for the heat resistant parts that the user touches. After considering the key properties in
the fig. B.4 seen below, stainless steel and wood were found to be the best alternatives.
Thermal
Properties
Mechanical
Properties
Fig. B.4: Material Property Comparison for Steel vs. Aluminum and Wood vs. Polycarbonate
AISI 304
Material
Aluminum
Wood
Polycarbonate
Stainless Steel
50 lb/ft³
75 lb/ft³
Density
0.289 lb/in³
180 lb/ft³
Young’s Modulus
30 E6 psi
11.9 E6 psi
0.435 E6 psi
0.3 E6 psi
Yield Strength
145 ksi
70 ksi
0.8 ksi
10 ksi
Fracture
Toughness
Maximum service
temperature
Thermal
conductivity
Thermal expansion
coefficient
137 ksi in0.5
30 ksi in0.5
0.7 ksi in0.5
4 ksi in0.5
1.5 E3 ºF
400 ºF
260 ºF
290 ºF
13.9
BTU.ft/h.ft2.F
130
0.1
0.12
BTU.ft/h.ft2.F BTU.ft/h.ft2.F BTU.ft/h.ft2.F
11 µstrain/ ºF
13 µstrain/ ºF
23 µstrain/ ºF
77 µstrain/ ºF
Friction: Based on these characteristics, coefficient of friction between surfaces was considered
and steel was found to be more suitable for the legs, because the plate lock will be made of steel
and therefore, the legs will need to be thick enough so that they are not pliable, and thin enough
to avoid extra weight. That said, steel on steel provides a high surface-to-surface static
coefficient of friction,µ𝑠 , of 0.5-0.8, while aluminum to steel allows for a maximum static
friction coefficient of 0.45. This a key aspect of the legs’ locking mechanism, as it relies solely
on the friction between surfaces in order to achieve a non-discrete system to allow self-levelling
at infinitely small increments.
42
Force Analysis
The forces acting on the grill can be analyzed by viewing it as a whole and by looking into the
individual locking and folding subsystems. Additionally, deflection of side tables is modelled
using cantilever analysis and Solidworks. In the case of the four folding brackets, the force is
exerted on the hinges urging them to open past the deployed position. These are not subject to
failure as products available in the market were found to support forces of 75lbs. each. Given
that only a fourth of the total force would be applied to a single hinge, 300lbs. is far greater
than the maximum 150lbs force expected to be applied. Forces acting on the grill assembly can
be represented with a free body diagram seen below in fig. B.5.
Fig B.5: Grill Free Body Diagram; Front & Side View
𝐹𝐷𝑂𝑊𝑁
14.25”
24.625”
32.6”
𝐹𝑆𝐼𝐷𝐸
𝑊𝐺𝑅𝐼𝐿𝐿
𝑊𝐺𝑅𝐼𝐿𝐿
10°
LEG 2
10°
LEG 1
LEG 1
𝐹𝐺𝑅𝑂𝑈𝑁𝐷,1𝐴 =
𝑊𝐺𝑅𝐼𝐿𝐿 + 𝐹𝐷𝑂𝑊𝑁
= 𝐹𝐺𝑅𝑂𝑈𝑁𝐷,2𝐴
4
𝐹𝐺𝑅𝑂𝑈𝑁𝐷,1𝐵 =
LEG 3
𝐹𝑆𝐼𝐷𝐸
4
The two views of the grill depicted above illustrate the aggregate of the forces acting on the
grill on all axes. In addition to the weight of the grill, there is an external force on the grill due
to the weight of the food being cooked and utensils placed on its grate, magnified by the
weight of the users pushing the grill downwards. This force is represented as FDOWN and is
estimated to be a maximum 15 lbs., in which the weight of the food being cooked and cooking
utensils is considered as explained further below, magnified by a safety factor of 2. The mass
manufactured grill weight is estimated to be approximately 40lbs.
In the case of static equilibrium, the combined downward force and weight total is equal and
opposite in direction to the total of four reaction forces from the ground on to the legs. That
said, the force FSIDE illustrated on the side view of the grill, represents the force exerted by the
43
user when he/she accidentally falls on it. This is a measure that aims to prevent a fire as
explained in the safety plan section of this report. The user weight of 240lbs is used to estimate
the component 125 lbs. of weight exerted laterally on the kettle, represented by FSIDE.
Assuming the user hits the kettle at a 45 degree angle only half the force (i.e. 120lbs) is
transmitted to the kettle sideways, which is estimated by studying the ergonomics of cooking.
Added to the 120lbs. is the weight of 5lbs. exerted by 20 1/4lbs. burgers. This force
encompasses not only the average male weight of 180 lbs. but also one standard deviation of
the population weight distribution, thus designing for variability. It should be noted that the
lateral force, FSIDE, can be exerted on any of the four sides of the grill, with the same effect,
since the legs are angled outwards by 10 degrees to the perpendicular in every direction. The
side view is just an example case.
Bar Clamp Lock Static Equilibrium: Under normal circumstances, the main failure mode
will be leg collapse due to locking malfunction. The impact of the anticipated weight and
external downward force onto the lock can be represented with the use of a bar clamp model
force analysis. A clamping force transmitted by the pivoting motion of the lock onto the lower
leg holds the legs in the desired position. The clamping force holds the lower leg against the
locators. The locators can usually resist huge thrust forces and are therefore used for industrial
applications. The arc in which the lock moves about the pivot forces the lock into the lower leg
laterally. The spring force pulling the lock into place creates a normal force applied from the
lock to the lower leg and counteracting its tendency to move upwards, which would cause the
legs to collapse. As shown in the above free body diagram the total downward force exerted
on the grill is counteracted by an equal and opposite upward force from the ground.
FGROUND,1A, which is a fourth of the downward force, is then neutralized by the clamping force
thus bringing the grill support into static equilibrium, as illustrated in fig B.6 below.
Fig. B.6: Locking mechanism with force analysis
44
Since the leg is angled at a degrees to the perpendicular, the force acting upwards on the lower
leg is the ground force multiplied by the cosine of 10 degrees. The force acts on the lock and a
reacting force acts on the leg from the lock, the vertical component of which is the clamping
force stopping the lower leg from collapsing. The moment induced by the angle to the vertical
is minimal because the angle is only 10 degrees. As a result, no deflection is expected on the
legs or hinges.
Possible irregular lateral force, Failure of locking plates: A very minimal component of
force is transmitted to the lock due to the 10-degree angle to the perpendicular at which the
legs are placed and is thus not going to be sufficiently large to cause lock failure. Namely the
force due to the weight of the 220lbs. will be much smaller than the forces under which the
lock collapse will be tested to. Please refer to the validation plan section of this report for a
description the leg collapse testing.
Tip-over with locks in static equilibrium: By assuming that the locking mechanism and
hinges are fixed on all four legs, the grill can be treated as one rigid body and simplified to the
following box model, where infinite friction acting on the leg at the ground surface creates a
no-slip condition as seen below in fig. B.7. The lateral force is then entirely directed to tipping
the body. Until the body starts tipping, this rigid assumption is still in effect. After tipping
starts the forces on the lock increase thus causing a collapse to be possible as well. For the pretipping stage though the force equilibrium can be represented with the following diagram. The
normal reaction from the ground is modelled as twice the ground force since the grill will be
supported by two of four legs when tipping starts. The sideways force is estimated as half the
weight of an average male multiplied by gravitational acceleration. This analysis was based on
information found in the 6th edition of J.L. Meriam and L.G. Kraige’s Engineering Mechanics:
Dynamics textbook.
Fig B.7: Tipping analysis free body diagram
45
Side Tables Cantilever Analysis
The side tables are engineered to withstand a load of 10 lbs. of concentrated load acting on the
far end of the side tables. The magnitude and point of application used for the maximum design
load were selected using a safety factor of 2 and the fact that the side tables are anticipated to
support one or two beverages as well as a plate of food and a few cooking utensils. This is an
extreme case, since load will typically be distributed and placed closer to the center of the tables.
3D cantilever beam deflection analysis, based on Hibbeler’s 3rd edition of Statics and Mechanics
of Materials, is presented below. The 3D model was then modelled with a stress-strain and
deflection analysis using Solidworks. This load was chosen to simulate approximately twice the
weight of a large plate of piled high with16 quarter pound burgers, plus the weight of extra
seasoning/condiment containers. For more details, please refer to the validation plan section of
this report.
3D Deflection Principles:
Nomenclature:
L = 14.25
b = 12.312
h = 1/16”
P = 20lbs
E = 180 GPa
Length of beam
Cross Section Base
Cross Section Height
Concentrated Test Load
Young’s Modulus of AISI 302
Stainless Steel at 21° Celsius
The stress acting on the side tables of the grill can be found using the Von Mises model, where
2 1/2
𝜎 ′ = (𝜎𝑥2 − 𝜎𝑥 𝜎𝑦 + 𝜎𝑦2 + 3𝜏𝑥𝑦
) . Since the nodes of in this case are located at the top surface
of the beam, the shear stress at this location is zero. Therefore:
𝑃(𝑥−𝐿)𝑐
𝜏𝑥𝑦 = 𝜎𝑦 = 0, and 𝜎 ′ = 𝜎𝑥 =
𝐼
, where 𝐼 =
𝑏ℎ3
12
ℎ
and 𝑐 = 2
Using Shigey’s Mechanical Engineering Design, the maximum beam deflection is:
𝛿𝑚𝑎𝑥
𝑃𝐿3
=
3𝐸𝐼
The 3D deflection analysis for the side tables was modeled with Solidworks, because it is
expected to be the most frequent most failure. Namely, it is very likely that users will place very
heavy items on the side tables, so analysis needed to be made in order to place warnings on them.
The analysis was done using SolidWorks eDrawings and is illustrated below with screenshots of
stress distribution and deflection. This was modelled by placing a load of 10lbs on the side table
and adding a fixture to the curved side of the side table which is the one attached to the kettle.
Figures B.8 and B.9 on pg. 46 prove that sheet stainless steel is a good fit for this subsystem.
46
Fig. B.8: Side table Von Mises stress distribution
The von Mises stress along the side table for sheet steel side tables was calculated to be range
from 4215 N/m2 at the far edge of the table all the way up to 120,433,408 N/m2 at the fixture.
Fig. B.9: Side table deflection under 10lbs point load acting on far end
The resultant vertical deflection of the side table ranging from 0mm right next to the fixture all
the way up to 9.5mm at the far end. The deflection is under 0.4” and is therefore very minimal.
Using thicker material would hurt the portability of the grill and is therefore deemed
unnecessary, especially since the test load is greater than the load anticipated. URES which is the
representing variable for deflection stands for Resultant Displacement, with U being the
displacement vector with components Ux, Uy, Uz.
DESIGN FOR X
A successful product cannot just start as a single great idea, it must fit into the surrounding social
and environmental context that will make up its home and users. Therefore, the grill design was
scrutinized under several different lenses to ensure that certain real world issues where at least
considered during the design process, or even changes made to accommodate such things as the
product validation, manufacturing, assembly, environment, and end user.
47
Design for Manufacturability
In order for a concept to brought to life on an economically feasible scale, the product must take
into account production methods and limitations. Throughout the design, the team considered
both how the grill will be manufactured, and assembled. Most of the parts will be made of sheet
steel which is a relatively tough material and therefore more expensive to machine due to
increased tooling costs. However, this is economically viable in larger quantities if steel pressing,
forming, or stamping are used. The steel is also easier to weld than other metals and this joining
method is very sturdy for the intended long lifespan of the grill under various weather conditions.
Automated welding procedures can be used if a high enough volume of the product is to be
manufactured to reduce human labor costs while improving product consistency.
By avoiding highly irregular shapes or patterns, the manufacturing process is also improved
because less time or specialized machinery would be needed to create such pieces. By
modularizing the design into the legs and associated mechanism and the kettle and its
attachments the grill can be completed in separate stages for final assembly. Here specialized
workers or machines can deal with familiar tasks thus improving speed and quality. Similarly, by
using many premade components, manufacturing will have to be less specialized. Items like a
grill grate can be sourced, thus the in-house plant will not need to have the ability to work with
tubed or cylindrical forms. Most will in fact be formed from basic sheet steel. This also makes
the product easier to service or for replacement parts to be sourced for the consumer.
The choice of sheet steel for major structural components allows for stamping to be used instead
of welding, thus greatly reducing labor costs. Also, on a large enough scale, sheet stamping can
produce with ease the stylish curves that a human could not form economically. But because
some shapes like a handle cannot be formed as one from a single sheet, some labor in terms of
welding or assembly is required. Most parts that cannot be made in this fashion in- house will
have to be sourced from a supplier, and these parts were minimized to reduce cost or supply
chain issues. In addition, all parts designed to interface with sourced parts have the free-play to
allow for similar parts from other manufacturers without loss of function or quality.
The design was also made to be assembled easily in house prior to distribution, this will virtually
eliminate customer hassle as they are not required to perform any assembly, unlike competitor
products. The legs serve as a good example of a design tradeoff taken to benefit assembly. While
a circular profile leg would reduce cost and material while improving strength vs. weight, it was
instead decided to use squared legs for ease of manufacturing the locking mechanism, and the
legs attachment to the hinge and to provide more contact area with the kettle when deployed for
improved stability. Also, the use of many components from outside suppliers such as handles,
thermometer, and many hinges or other hardware will make the final product easier to assemble
in the modules or stages as previously described. By reducing unnecessary parts or assembly
steps, the manufacturing process can speed up, use less material, and cost less. This will help
produce an economically viable product.
Design for the Environment
With the world changing and customers being more aware of the environmental impact of the
products they purchase, it makes sense to design products that consider the this not only to please
the customer, but also to be stewards of the world thus ensuring future customers, and because
48
many things that are good for the environment also can reduce costs through wasted materials,
process steps, or unnecessary functions. In order to assess the product’s impact on the
environment throughout all stages of life, a lifecycle assessment was completed using the life
cycle assessment tool in CES [C.13]. Additional information was sourced from lectures on life
cycle assessment and sustainable design [C.18].
The new development phase has some of the largest impacts because choices here will propagate
throughout the lifecycle. In this stage, the product was determined to have customer want
through market research, thus preventing the waste of an unnecessary part or function. Also,
several functions were combined into individual parts; the handles for instance not only provide
a way to transport or adjust the grill, but also will have integrated into them the function of
operating the latch release for leg deployment and also the spring loaded pins that hold the upper
grill grate in place. Next, by minimizing the use of physical material in the design, waste is
eliminated. While it would seem stronger to choose a thicker gauge steel or hinges and supports
capable of far greater loads, this would be excessive in terms of the resources needed to the
actual need of the product to handle this in service. By reducing the physical size of the product
and combining features like side tables with a lid further exemplifies how the design was created
with environmental concerns in mind.
In terms of the materials used, the grill will be made almost entirely of steel, which despite the
possible negative effects associated with mining would be the best material for the job and its
quantity used was limited as possible. Steel also has the benefit of being recycled at the end of
product life, and since so much of the design is steel most of the drill will be able to be recycled.
Also, the grill was designed to be durable, through stainless steel and coating to inhibit rust and
other wear. This means that the grill will be re-usable perhaps after the first owner no longer
desires it. And if the grill will be able to remain functional for a long period of time, this reduces
the need to purchase other grilling equipment.
Further savings both financially and in reduction of environmental impact can be had with
changes to the manufacturing and distribution processes. By using less power intensive practices,
and having less scrap materials, or waste products emissions from power generation are reduced.
Furthermore, if the manufacturing of parts and sources are within a reasonable distance, the
impact from transporting materials through trucks can be reduced and costs as well. This same
outcome can come from having a more compact design. The fold-ability of the legs and relative
square shape make it easy to transport and have minimal unnecessary packaging. If only
cardboard or other recyclable paper products are used this too can be environmentally beneficial.
Lastly, thought was put into reducing the waste and environmental impact of the grill during
operation. Because charcoal was chosen, it will have a greater impact on emissions of carbon
dioxide than propane. However, several things were considered to mitigate this. By
concentrating the heat, less charcoal would be needed, but other constraints necessitated a square
grill design. As a possible countermeasure, the inside steel can be polished thus reflecting the
heat within the enclosure. Also, cooking for more people in one use would limit the number of
charcoal needed if the grill were to be smaller. Therefore, the choice to make a large grill grate
that has the capacity to cook for a large group is environmentally beneficial in reducing Carbon
49
Dioxide emissions because the grill will not need to have coals replaced often. Overall, the
environment was considered during the design of the all-terrain grill.
Design for the Human
In order for a product to be successful, it must take into account its intended user, operator and
owner. For this reason, the grill was designed with this in mind. In particular, attention was paid
to the aesthetics of the grill, its form, shape, and beauty. The typical user and their interaction
and enjoyment of using the grill was also considered. And because there may be users other than
those targeted, the grill was designed with variability in mind to accommodate a wide range of
potential users.
Aesthetic Considerations: In order for the grill to be pleasing to the customer, its proportions
were considered, and a study undertaken for a key feature of the grill. Additionally, the overall
visual appearance was compared to other successful outdoors products that might be appealing to
the typical customer, a male in his early to mid-20’s from an urban or suburban setting, and a
potential recent college graduate.
The outside profile of the overall grill in its stored position, the kettle and lid when deployed, the
entire deployed grill, and the grill legs were all closely examined from a dimensional
perspective. It has been seen that many past successful or aesthetically pleasing products share a
ratio found in nature referred to as the golden ratio. This might mean that one length is 1.618
times longer than the other in case of the sides of the kettle. Design dimensions were chosen to
meet other specific customer requirements and as such cannot be changed to meet the golden
ratio because it would interfere with the functionality of the grill. The legs must be long and
narrow to provide the appropriate grill height, the kettle is confined to the rectangular profile of a
grill grate with enough capacity to cook for upwards of 10 people and in each case the material
used is to be minimized to reduce weight. The height of the kettle is the same, it must only be tall
enough to allow enough space for ash collection, coals at an appropriate distance from the
cooking surface and all with enough room to fit the lid inside. Therefore, proportional aesthetics
were considered, but not applied to the main grill features.
However, many features of the grill, and its shape might be beautiful to the user. Because many
customers enjoy the outdoors, and many similar products are very masculine and looks like they
belong in the woods the grill was chosen to embody these traits. The dark black gloss coating is a
timeless color for a grill and provides excellent durability or protection from the elements as seen
from the success of outdoors or grill products with this finish. The legs were chosen to be square
as opposed to round to add a more masculine and chunky look similar to the styling of trucks and
SUV’s. The research the automotive manufacturers did on this subject certainly apply to
something as timeless and masculine as a grill. The rest of the grill is also shaped in this way, but
the folding tables are slightly thin in comparison but are meant to look strong and stable
regardless thanks to the ample support. The ash tray will be made of a finely brushed aluminum
to minimize heat to the user as they discard the waste while providing some contrast to the dark
gloss mass and break up the monotony of the grill. This is the sort of tasteful accent seen in many
male oriented products like razors, or tools.
50
Additionally, the grill will have wooden trimmed handles to further provide a masculine and
rugged outdoors look that the user desires. To help understand this choice further, Kansei
Engineering was used. Using the decomposition method it was determined that comfort and the
rugged look and feel of the handles were most critical. From this, the semantic differential
method was used to create a survey which was distributed to potential customers given the
choice of a rounded or squared style handle with either a light finish or a darker stained wood.
From this survey, a regression analysis was conducted on the data regarding the comfort and
ruggedness of each possible combination. The results are plotted in the Pareto Optimization chart
seen below in fig. B.10. From this visual and the regression model, it can be seen that a rounded
handle with a dark wood finish is the most appealing to the customer to maximize user comfort
and perception of beauty through a rugged look.
Fig. B.10: Pareto optimization chart with characteristics of wooden handle shown; shape first
then grain finish. Notice the most optimal choose is a rounded handle with a dark finish to
maximize comfort and rugged feel or appearance.
User Enjoyment Considerations: The user’s interaction with the grill is paramount in the
pleasure they will derive from it. To further understand this interaction, the typical customer’s
thoughts were delved into to get a deeper understanding of their motivations. The goal here is to
provide a design they will fall in love with, cherish and keep. Because the user is in their early
20’s they have an interest in more modern designs yet feels an instinctual connection to the earth
and outdoors that they enjoy to share with their friends a form of social pleasure. They feel that
they are quite wise in terms of the outdoors, cooking and feel a sort of deep satisfaction in
providing for their friends by cooking for them. This provides them a sense of purpose and
feeling of power as having the knowledge to survive, a form of reflective pleasure. The grill was
designed to enhance this confidence in the user, by providing the masculine design, with a large
cooking capacity and great durability for the outdoors environment.
The grill was designed to be comfortable to the touch at the handles yet rugged looking. The use
of a coated sheet steel will be cold in his hands as he touches its surfaces and this cold steel gives
51
him the feeling of strength in his hands, because he has the power to turn it into a tool with his
knowledge and this is a mix of physical and psychological pleasure. Every operation, from the
grasping of the handles to release the telescoping legs and pull up to fully adjustable height is
meant to show off that the user has made the right choice and is in control of their surroundings.
However, some potential frustrations with the operation of the product might lead to displeasure.
The need to wait for the grill to cool down, to have to dispose of ashes before transport might be
of annoyance. That is why the ash tray was added to minimize effort. The user might also
struggle with the legs folding, and or the telescoping locking function since it is combined with
the grate release function. Frustration that might occur in retrieving the grate from the ash tray
when unintentionally actuating the lever was mitigated by having a lock mechanism in the
release so it can’t be accidentally pushed. Overall, there are some possible sources of displeasure
with use of the grill as is to be expected when anything is designed because there will be
tradeoffs, but an attempt was made to mitigate these concerns while maximizing user pleasure.
User Variability Considerations: In order to properly design a grill that can be carried and set
up, certain characteristics of potential users had to be considered. To get a better understanding
of the user’s interaction with the grill, a task analysis was completed. At each stage, the human
inputs required to function were assessed and compared to anthropomorphic data for the average
human as found in the .S. Army ANSUR survey from 1998 [1]. As would be expected, most
operations require the user’s hands on the product. The four main steps are grill transport, set up,
use, and packing up.
For the transport stage, the handles were spaced far enough apart such that the average male can
comfortably lift and support it. For this reason the mass of the grill was minimized to reduce
fatigue, and with a target weight under 20kg, most adult males and even females should have the
ability to lift and carry the grill [2]. Because the average male’s shoulder breadth is about 20
inches, it should require only a slight outward reach of the hands to grasp the handles which are
about 26 inches apart. Additionally, the handles themselves were important in all stages
requiring the user to lift, carry, and unlock the leg telescoping mechanism. For this reason the
handles usable width was designed to be 4 inches which should accommodate most people as the
average male hand or palm width is about 3 inches. Here, the added length allows for some
variance on the larger end that might be a result of a bulkier male while accommodating all
people with smaller hands easily. The use of wood for the handles will also reduce the heat felt
during operation so the average user will not experience pain, discomfort or be burnt.
For the setup, breakdown and cooking stages, the user will again need to use hands to manipulate
the legs, ash tray, lid, and unlock mechanisms and be able to lift the grill slightly. These actions
were taken into account such that the amount of force required is minimal thus ensuring a wide
range of users can operate it. Also of great importance is the height of the fully assembled
cooking surface. At around 2.5ft tall the grate is slightly under the average waist height of an
adult male at roughly 3 feet. Considering most people’s hand length puts them below the waist,
this is the ideal height to minimize stress and user fatigue while accommodating smaller adult
users easily. Because measurements were from the 95th percentile male and female, both these
target groups, a vast majority of the adult population, should have no trouble operating the grill
within its adjustability range. This matches the height of many charcoal grills on the market as
52
well. Other capabilities are required other than physical as well. The user will need sight to set
the grill up and operate it especially for the first time. It is conceivable that after repeated use the
leg lock mechanism and other functions will become second nature. Sight would also be needed
to read the thermometer and level. These have been placed in a location that most users should
easily be able to see such as the kettle for the level and lid for the thermometer.
Design for Testing
Many times a design is slightly different for its prototype form to allow for test equipment to be
fitted or other reasons. The grill was designed to be a fully functioning prototype and as such
should be able to withstand all tests. The leg stability test will require weights, but these can be
placed on the kettle so additional changes to the design were not necessary. For the tipping test
as well, modifications were not needed. The level attached to the kettle was added for the user,
but is critical for ensuring the cooking surface is level. The uneven terrain tests require this, and
there is the potential to remove it after testing if customer demand is not there. In order to get an
accurate setup time, the grill was made to be in its intended final form. The same is true for the
heat dispersion testing as an infrared thermometer will be used to determine surface temperatures
so the design was unchanged. If more extensive testing were to be done, thermocouples could be
strategically mounted to the grill and holes or supports would be needed for associated
instrumentation. Load cells could also be added to the legs, joints or other areas requiring further
investigation. This would necessitate modifications to the structure. Overall, the design did not
require modified to accommodate testing because it was already in a suitable form for the style
of tests that to be performed. Should it be needed in the future if more tests are deemed
necessary, the design could be modified easily.
FINAL DESIGN
From the design drivers, the previous proposed concept idea, and the technical analysis of
materials, parts, and ability to survive the intended use, a design was made in Solidworks. From
this design, engineering drawings for parts not purchased and the details necessary to reproduce
the design are in the next section.
Kettle Design
A screenshot of the final design is seen on pg. 53 in fig. B.11 in the deployed position and in fig.
B.12 on pg. 54 in the stowed position. Notice the top half of the grill is composed of a rounded
kettle made of 16 gauge stainless steel for corrosion resistance and texture/appearance. There are
vents on the shorter sides that allow for air to flow thus permitting combustion with the lid
closed. Notice the opening at the base of the kettle, this houses the removable ash tray which is
another stainless steel rounded form with a handle that is covered in a dark stained rounded wood
finish accent. The ash tray when in the kettle is secured by light magnets, to prevent it from
falling out during transport, against the back wall and will have a lower grate resting on it that
will support the charcoals, and then once grilling is over the ashes will fall into the tray which
can be easily removed for cleaning. When this is removed, the lower grate will come with it for
cleaning as well. The upper grill grate will rest on spring loaded pins attached to a release handle
that is integrated to the side handles of the kettle which also have the same wood finish
previously mentioned. The function of these handles will be discussed later. The grate is
corrosion resistant steel and large enough for 10 burgers to be cooked simultaneously.
53
With the upper grill grate released, it can fall onto the other for easy removal with the ash tray
and this is its stored location during transport. The stainless steel lid will sit on the grate during
cooking and will also when the pins are released, but now it will be within the kettle. Notice the
lid also has a handle with trim like the others, a built in thermometer, and an adjustable air vent
for proper temperature and flame control during cooking. On the side of the kettle are hinges and
support brackets for folding tables that will form the lid of the closed grill and latch shut. When
open they will rest on the supports and be a good plate to keep a plate of food, cooking supplies,
or other smaller items. Also attached to the kettle is a handy bubble level to ensure the grilling
surface is level. This comprises the top half mechanism, which is its own subsystem and will
interface with the supporting bottom section at mounts to the underside of the kettle.
Fig. B.11: Isometric screen capture of the final CAD design in the open and upright position.
Support Structure and Leg Mechanism
The bottom half of the design is the support structure and leg lock and leveling mechanism thus
allowing for a level grill on uneven terrain, again refer to fig. B.11 above. Notice the four
telescoping stainless steel leg sections that angle outward past 90 degrees for stability. This is
accomplished my shimming one end of each of the self-locking 90 degree hinges used. These
will have to be manually pulled out and pushed back in when switching from stored to deployed
mode and vice versa. This is done by tipping the grill over, pushing the locking tab on the hinge
and then pulling the hinge out. These hinges are angled such that they face the leg at a 45 degree
angle from the corner of the kettle underside inward such that the legs store in the line from one
54
opposing corner to the other. This reduces likelihood of tipping while allowing for a longer leg.
The outer leg is longer than the inner so that the inner is always in contact with the locking
mechanism. The inner leg has stops to prevent overextension. Additionally, each leg can only
rotate in one plane.
Fig. B.12: Isometric screen capture of the final CAD design in the stowed position.
Lock Release Actuation: Once the kettle legs have been opened outward and locked the legs are
ready to be telescoped. While the kettle side handles are used to lift and carry the grill, there is a
separate release handle is that rides along the support for the grab handle used for lifting the grill.
This secondary pull handle, or mechanism will be attached to the springs and pins for the grill
grate, but also have a cable attached that when pulled will decrease in length and effectively
actuate the leg telescope lock release mechanism. These cables have been routed up the legs and
combined into one for each of the legs on the shorter sides of the kettle adjacent to the handles.
Cable guides translate the horizontal motion at top to a vertical and downward motion at each
individual leg lock. This mechanism works like an adjustable bar clamp. It pivots off the top leg
and wraps around the inner leg. A spring loads this plate against the inner leg which then grabs
the corner of the plate and pins them together. The force is transmitted at an angle thus locking
the legs together. To release this mechanism, a cable will be pulled upward against the spring
pressure thus allowing the inner leg to now slide freely within the outer leg. The cable is routed
up each individual leg and joined at a common center support for the two legs closest to each
handle. Then the combined cable routes to the release handle. This way each of the shorter two
sides controls the legs on their respective sides as a unit.
With the legs folded down, the inner lever on each side is pulled towards the outer handle as the
grill is lifted upwards to the desired height and each leg can adjust to its own height
independently. Then the pull lever is released and the legs lock, the level on the kettle can
confirm the grill is level.
55
Lock Design
The locking mechanism is designed to be always on, and can only be released by manual input.
Notice the black upper leg, in fig. B.13 below, and the silver inner leg that is normally free to
slide within the upper leg but is held in place by the grey locking mechanism. The tension spring
pulls the upper lock plate against the lower leg. Since it is also constrained from moving,
wedged, on the opposite side by the piece attached to the upper leg, the force is transmitted
through the inner leg to the lock plate, to the support and upper leg as a static unit. The low angle
relative to horizontal to concentrate all the normal force against the wedged point. Friction
between the steel materials also contributes to the prevention of slip. In order to release the
mechanism, the cable attached to the plate is pulled. The cable is routed through the spring
mount and cable guide seen to redirect the motion of the pulling action so the control cable can
be routed up to the handle. The downward motion works against the spring and as the angle
opens to 0 degrees, the opening is in effect larger than that of the inner leg while before it was
the same. The leg can then be pushed up, or let fall by gravity. To prevent overextension there is
a hard stop at the top of the upper leg and a guide wire securing the lower leg to prevent
overextension.
Fig. B.13: Screenshots of the locking mechanism from a side and isometric view.
MANUFACTURING PLAN
The following section will detail the final design in terms of technical drawings and figures, the
parts needed to make it, manufacturing or fabrication instructions for made parts, assembly
instructions for the finished product, a bill of materials, and other considerations. The final
design is detailed on pg. 56 in the form of an assembly parts list. For the bill of materials, see
Appendix D fig. D.1
56
ASSEMBLY PARTS LIST (Mass Manufacture Design):
1. Thermometer x 1
13. Leg Hinge x 4
2. Wood Handle x 4
14. Outer Leg x 4
3. Stamped Handle x 3
15. Locking Mechanism Piece 1 x 4
4. Grill Vent x 1
16. Locking Mechanism Piece 2 x 4
5. Grill Top Lid x 1
17. Locking Mechanism Piece 3 x 4
6. Grill Grate x 2
18. Inner Leg x 4
7. Folding Side Plate x 2
19. Ash Tray x 1
8. Folding Table Hinge x 2
20. Bump Stops x 4
9. Actuating Spring x 4
10. Actuating Inner-Handle x 2
11. Actuating Cylinder x 4
12. Kettle Body x 1
57
MANUFACTURING & FABRICATION PLAN
Part Number: ME455-001
Part Name: Grill Vent
Team Name: Special-T
Revision Date: 12/8/2013
Raw Material Stock: 304 Stainless 16-gauge sheet steel (4” x 4”)
Alro Steel
Step
#
1
2
Process Description
Place Sheet metal in die and stamp
out 3.5” circular steel vent
Remove scrap for recycling from
rounded edges
Machine
Hydraulic
Press
Hopper
58
Fixtures
Die
N/A
N/A
Speed
(RPM)
N/A
Bin
N/A
Tool(s)
59
Part Number: ME455-002
Part Name: Steel Handles
Team Name: Special-T
Revision Date: 12/8/2013
Raw Material Stock: 304 Stainless 16-gauge sheet steel 6” strips
Alro Steel
Step
#
1
2
Process Description
Place Sheet metal in die and stamp
handles
Remove scrap for recycling from
rounded edges
Machine
Hydraulic
Press
Hopper
60
Fixtures
Die
N/A
N/A
Speed
(RPM)
N/A
Bin
N/A
Tool(s)
61
Part Number: ME455-002
Part Name: Wood Handles
Team Name: Special-T
Revision Date: 12/8/2013
Raw Material Stock: 304 Stainless 16-gauge sheet steel 6” strips
Alro Steel
Step
#
1
2
Process Description
Turn Wood Piece to ½”
Split into two hemispheres
Machine
Lathe
Band
saw or
Circular
saw
62
Fixtures
chuck
N/A
Tool(s)
Facing tool
Wood block
Speed
(RPM)
500
600
63
Part Number: ME455-003
Part Name: Grill Grates
Team Name: Special-T
Revision Date: 12/8/2013
Raw Material Stock: Cast Iron steel
Alro Steel
Step
#
1
2
Process Description
Poor Cast into dedicated mold
Remove flash for recycling from
rounded edges
Machine
Kiln /
Furnace
Fixtures
N/A
Hopper
N/A
64
Tool(s)
Sprue, crucible,
ladle, heat resistant
suit
Bin
Speed
(RPM)
N/A
N/A
65
Part Number: ME455-004
Part Name: Kettle Body
Team Name: Special-T
Revision Date: 12/8/2013
Raw Material Stock: 304 Stainless 16-gauge sheet steel (35” L x 26” W x 0.0625” H)
Alro Steel
Step # Process Description
1
Place Sheet metal in die and stamp kettle
body
2
Remove scrap for recycling from
rounded edges
Machine
Hydraulic
Press
Hopper
66
Fixtures
Die
N/A
N/A
Speed
(RPM)
N/A
Bin
N/A
Tool(s)
67
Revision Date:
12/8/2013
Part Number: ME455-005
Part Name: Removable Ash Tray (Drawer + Handle)
Team Name: Special-T
Raw Material Stock: 304 Stainless 16-gauge sheet steel
(24.5”L x 14.19” W x .0625” H)
Alro Steel
Step
#
1
3
Process Description
Place sheet metal in die and stamp out ash
tray and remove any remaining burrs
Machine
Hydraulic
Press
Fixtures
Die
Tool(s)
Flat File
Welder
Clamps
MIG
Welder
Tack-Weld 4” tray handle at center
(symmetrically) from edges
Tack 1: X: 10.25”, Y: 0”
Tack 2: X: 14.25”, Y: 0”
68
Speed
(RPM)
N/A
N/A
69
Revision Date:
12/8/2013
Part Number: ME455-006
Part Name: Locking Part (#1 - #3) x 4
Team Name: Special-T
Raw Material Stock: Galvanized 12-gauge carbon steel plate (0.5” x 0.5”)
Alro Steel
Step
#
*Alternative Process Description
Cut using all three pieces from
1 Water-Jet in order to assemble
Weld pieces to create assembled
2
mechanism
Speed
(RPM)
Machine
Fixtures Tool(s)
Water-Jet
Clamps
Water-Jet
N/A
MIG WELDER
JIG
MIG WELDER
N/A
70
71
72
73
Part Number: ME455-007
Part Name: Grill Top
Team Name: Special-T
Revision Date: 12/8/2013
Raw Material Stock: 304 Stainless 16-gauge sheet steel
(24”L x 14”W x 0.0625”H)
Alro Steel
Step
#
1
2
3
4
Process Description
Mark location for top-handle holes
on top plate (24” L x 14” W x
0.0625” H) datum is lower left
corner of top plate
Hole 1: X: 9”, Y: 6”
Hole 2: X: 15”, Y: 6”
Drill two holes for temperature
gauge and grill vent located at
Hole 1: X: 19.55”, Y: 7”
Hole 2: X: 4.45”, Y: 7”
Drill Three 1.5” dia. holes 120°
apart with the outermost hole center
located at
X: 20.03” Y: 6.75”
Place sheet metal in die to stamp
grill lid
Speed
(RPM)
N/A
Machine
N/A
Fixtures
N/A
Tool(s)
Scribe, Marker,
Height Gauge
Drill
Vise
Drill Press
1/4” Drill Bit
Drill
Vise
Hydraulic
Press
Die
N/A
N/A
1.5” Drill Bit
750
150
5
Remove excess metal trim to be
recycled
Hopper
N/A
Bin
N/A
6
Tack-Weld handle symmetrically
centered to lid top
Welder
Clamps
MIG Welder
N/A
74
75
Part Number: ME455-008
Part Name: Side Table (Folding Doors)
Team Name: Special-T
Revision Date: 12/8/2013
Raw Material Stock: 304 Stainless 16-gauge sheet steel (15” x 13”)
Alro Steel
Step
#
1
2
3
Process Description
Drill two 0.2” dia. holes, datum is
lower left corner (dimensioned
from)
Hole 1: X: 0.75”, Y: 7.41”,
Hole 2: X: 0.75, Y: 6.6”
Place sheet metal in die to be
stamped (rounded/trimmed)
Remove excess material for
recycling
Fixtures
Clamps
Hydraulic
Press
Die
N/A
N/A
Hopper
N/A
Bin
N/A
76
Tool(s)
Drill Press
0.2” Drill Bit
Speed
(RPM)
750
Machine
Drill Press
77
Part Number: ME455-009
Part Name: Upper Leg (Outer Leg) x 4
Team Name: Special-T
Revision Date: 12/8/2013
Raw Material Stock: 304 Stainless 16-gauge sheet steel 8’ stock
McMaster Carr
Step
#
1
2
3
Process Description
Cut lower leg to 12” in length
Machine
Band saw
Drill one 0.125” dia. hole located
from lower left datum point
X: 0.5”, Y: 0.18” (as if it were a
square leg)
Clean burrs with round file for holes
and flat file for cut edge
Drill Press
Vise
Drill Press 0.125”
size Drill Bit
Vise / Jig
1000
N/A
Vise
Flat file & Round
file
N/A
78
Fixtures Tool(s)
N/A
Wood Block
Speed
(RPM)
600
79
80
Fig. 20: FMEA for the design, testing, and development stages.
ASSEMBLY PLAN:
LID
Step 1. Stamp lid surface (5).
Step 2. Weld Lid Handle (3) to grill lid surface indicated by the green arrow below.
Step 4. Place Thermometer (1) in grill top lid hole indicated by the blue arrow above.
Step 3. Place Grill Vent (4) into grill vent hole indicated by the red arrow below.
KETTLE BODY
Step 5. Stamp Kettle Body (12) including slot-gap for the Ash Tray (19) and “built in” stamped
declines for placement of Leg Hinges (13) in the next step.
81
Step 6. Weld Leg Hinges (13) at corners on the bottom of the Kettle Body (12) along the lines
indicated by the orange arrows and by the blocks’ locations.
Step 7. Butt-weld four L-shaped Bump-Stops (20) to Kettle Body (12) along the orange arrow
path.
Step 8. Butt-weld both Stamped Handles (3) to the Kettle Body (12).
Step 9. Attach wood-grain covers to the Stamped Plate Handles (3), Lid Handle (3) and Ash Tray
Handle (19)
82
Step 10. Weld Folding Table Hinges (8) to Folding Side Plates (7).
Step 11. Weld other side of Folding Table Hinges (8) to Kettle Body (12) above Stamped (side)
Handles (19).
Step 11. Place Actuating Springs (9) over Actuating Cylinders (11).
Step 13. Place Actuating Cylinders (11) into Kettle Body (10).
Step 14. Weld Actuating Cylinders (11) to Actuating Inner Handles (10).
83
Step 15. Run steel wire cables through Kettle Body (12) above the Stamped (side) Handles (10)
and through Kettle Body (base) (12).
Step 16. Attach steel wire cables to the Actuating Cylinder’s (11) flat surface indicated by the
purple arrow.
Step 17. Stamp Ash Tray (19) and weld a Stamped Handle (18) to Ash Tray (19).
Step 18. Place both Grill Grates (6) into the Kettle Body (12) and Ash Tray (19).
LEGS
Step 19. Place Inner Leg (18) inside Outer Leg (14) and weld to leg hinge that’s attached to the
kettle bottom
84
Step 20. Weld the Locking Mechanism Pieces (15) and (17) over the Outer Leg (16).
Step 21. Run steel cable from Actuating Cylinders (11) to outward-facing Locking Mechanism
Piece (17) attachment holes.
(15)
(16)
(17)
Step 22. Place Grill Top Lid (5) inside Kettle Body (12) Contract Legs for packaging.
85
PROOF OF CONCEPT FABRICATION
The following section will detail the proof of concept in terms of technical drawings and figures,
the parts needed to make it, manufacturing or fabrication instructions for made parts, assembly
instructions for the finished product, a bill of materials, and other considerations.
Design
A screenshot of the final design is seen on pg. 22 in fig. 13 with each part pointed out and listed
below. Associated quantities are also described. A more detailed part list is listed in the bill of
materials section and includes supplier information for those parts not manufactured in house.
The prototype designed below in intended to be the same as the finals design available to
customers. However, since some fabrication methods are more labor intensive, such as welding,
these operations may be computer controlled or the process replaced with a sheet stamping
process. This would be far more costly in terms of initial overhead and will be discussed later.
Variances Between Product and Prototype
There were several changes made from the proof of concept design to the mass manufactured
design and can be seen on pg. 88. Some of these changes were key mechanical components
while others were aesthetic additions that were made due to improved processes of mass
manufacturing. Stamping presses rather tack welding allow the design of the kettle lid and
drawer take on a curved contour rather than hard edges/corners which aids in both safety and
appearance. The change in these shapes also meant a change in the shape of the grate to a
“corner-less rectangle”. The grate will be in-house manufactured rather that purchased. In the
mass manufactured A.T.G. the actuation handles for the grate pins and the leg deployment lock
will be nested on a track inside the primary carrying handles. This will provide the look and feel
of a single handle rather the three separate mechanism possessed by the proof of concept design.
The shape of the side tables was also altered to a rounded contour in order to align properly with
the kettle when forming the locking lid for transport.
The largest design change was in the leg deployment locking mechanism itself. The final lock
design is pictured in fig. B.13, and the change in functionality and appearance is quite evident.
The tolerance of the lock opening will be machined a lot smaller to ensure a secure fit around the
telescoping leg. Also, rather than operating on a spring-loaded hinge the lock will function like
that of a bar clamp, but requiring actuation of the lock for leg movement both up and down. The
mass manufactured design keeps the same core values as the proof of concept, but it will look
much better and function much more efficiently.
86
Fig. 13: Exploded view diagram of final cad model with parts numbers and callouts.
ASSEMBLY PARTS LIST:
1. Thermometer x 1
2. Grill Vent x 1
3. Grill Top Lid x 1
4. Grill Grate x 2
5. Folding Side Plate x 2
6. Folding Table Hinge x 2
7. Actuating Spring x 4
8. Actuating Cylinder x 4
9. Actuating Inner-Handle x 2
10. Kettle / Grill Main Body
11. Ash Tray x 1
12. Bottom Hinge Shim x 4
13. Leg Hinge x 4
14. Locking Mechanism Hinge x 4
15. Locking Buckle x 4
16. Outer Leg x 4
17. Inner Leg x 4
18. Ash Tray Handle x 1
19. Side Plate Handles x 2
20. L-Shaped Bump Stops x 4
21. Lid Handle x 1
87
MASS-MANUFACTURED DESIGN CHANGES
New Mass Manufacture Design
Old Prototype Design
DESIGN CHANGES
1.
2.
3.
4.
5.
6.
Circular lid (3)
Circular Kettle Body (10)
Circular Ash Tray (11)
Locking Buckle Mechanism (14)
Circular Folding Side Plate (5)
Circular Grill Grates (4)
88
Parts Drawings and Fabrication Instructions
The following section details all the parts that must be assembled or manufactured. The
manufacturing or fabrication plan, as appropriate, is shown with the parts drawing following.
Part Number: ME455-010
Part Name: Grill Housing Side Plates x 2
Team Name: Special-T
Revision Date: 11/10/2013
Raw Material Stock: Ferric Basic Grade 430 16-gauge Steel Plate (14” L x 8” W x 0.0625” H)
Alro Steel
Step
#
1
Process Description
Mark side plates for the holes to be
drilled (plate is 8”x 14”x 24”).
Place plate in vise to machine with
end-mill
Machine
N/A
Fixtures
N/A
Mill
Vise
Datum Point is lower left point of
plate. Holes are 3/5 ” diameter
located at
Hole 1: X: 5.75”, Y: 6.5”
Hole 2: X: 8.25”, Y: 6.5”
Use center drill to drill two 1/2”
pilot holes
Mill
Vise
Edge Finder
900
Mill
Vise
400
5
Ream both holes with 3/5” reamer
Mill
Vise
6
Tack-Weld handle to locations
Tack 1: X: 0”, Y: 8”
Tack 2 X: 14”, Y: 8”
(Upper left and right corners of
plate, not shown on drawing)
Tack-Weld L-shaped bump stops to
locations
Tack 1: X: 3”, Y: Flush w/ top edge
Tack 2: X:11”, Y: Flush w/ top edge
Tack-Weld folding plate hinge to
side plates at locations (left hole or
the two on hinge)
Tack 1: X: 6.6”, Y: Flush with top
edge
Tack-Weld four locking-hinges to
the four corners of the bottom plate.
The middle part of the hinge ends
Welder
Clamps
Center Drill, Drill
Chuck, 0.5” Size
Drill Bit
0.6” Reamer or
3/5”
MIG Welder
N/A
Welder
Clamps
MIG Welder
N/A
Welder
Vise
MIG Welder
N/A
Welder
Clamps
MIG Welder
N/A
2
3
4
7
8
9
89
Tool(s)
Scribe, Marker,
Height Gauge
¾ Inch End-Mill,
Collet
Speed
(RPM)
N/A
N/A
400
are symmetrically placed at the
corners facing the absolute center of
the plate. Tack-Weld the outer
diameter steel tube to the other side
of the hinges.
90
91
Revision Date:
11/5/2013
Part Number: ME455-011
Part Name: Removable Ash Tray (Drawer + Handle)
Team Name: Special-T
Raw Material Stock: Ferric basic grade 430 steel
(24.5”L x 14.19” W x .0625” H)
Alro Steel
Step
#
1
2
Process Description
Tack-Weld (Butt-weld) four metal strips to flat
base plate (24.5”L x 14.19” W x 1.5” H). Two
strips are 14” x 1.5” (depth) and two are 24”L x
1.5”H
Tack-Weld 4” tray handle at center
(symmetrically)
Tack 1: X: 10.25”, Y: 0”
Tack 2: X: 14.25”, Y: 0”
92
Machine
Welder
Fixtures
Clamps
Tool(s)
MIG Welder
Speed
(RPM)
N/A
Welder
Clamps
MIG Welder
N/A
93
94
Part Number: ME455-015
Part Name: Hard Stop Leg Mechanism x 4
Team Name: Special-T
Revision Date: 11/5/2013
Raw Material Stock: Ferric basic grade 430 stainless 1/8” steel
Alro Steel
Step
#
1
*Alternative Process Description
Machine
Fixtures Tool(s)
Cut using Water-Jet
Water-Jet
Clamps
95
Water-Jet
Speed
(RPM)
N/A
96
Part Number: ME455-003
Part Name: Grill Top
Team Name: Special-T
Revision Date: 11/5/2013
Raw Material Stock: Ferric basic grade 430 steel (24”L x 14”W x
0.0625”H)
Alro Steel
Step
#
1
2
3
4
5
Process Description
Mark location for top-handle holes
on top plate (24” L x 14” W x
0.0625” H) datum is lower left
corner of top plate
Hole 1: X: 9”, Y: 6”
Hole 2: X: 15”, Y: 6”
Drill two holes for temperature
gauge and grill vent located at
Hole 1: X: 19.55”, Y: 7”
Hole 2: X: 4.45”, Y: 7”
Drill Three 1.5” dia. holes 120°
apart with the outermost hole center
located at
X: 20.03” Y: 6.75”
Weld four strips to base plate
(absolute top of grill) to create grill
top lid.
Tack-Weld handle symmetrically
centered to lid top
Speed
(RPM)
N/A
Machine
N/A
Fixtures
N/A
Tool(s)
Scribe, Marker,
Height Gauge
Drill
Vise
Drill Press
1/4” Drill Bit
Drill
Vise
Welder
Clamps
MIG Welder
N/A
Welder
Clamps
MIG Welder
N/A
Part Number: ME455-005
Part Name: Side Table (Folding Doors)
Team Name: Special-T
1.5” Drill Bit
750
150
Revision Date: 11/5/2013
Raw Material Stock: Ferric basic grade 430 steel
Alro Steel
97
Step
#
1
Process Description
Drill two 0.21” dia. holes, datum is
lower left corner (dimensioned
from)
Hole 1: X: 0.75”, Y: 7.41”,
Hole 2: X: 0.75, Y: 6.6”
Machine
Mill
98
Fixtures Tool(s)
Vise
1/4” Drill Bit
Speed
(RPM)
750
RPM
99
Part Number: ME455-017
Part Name: Lower Leg (Inner Leg) x 4
Team Name: Special-T
Revision Date: 11/5/2013
Raw Material Stock: Ferric basic grade 430 steel
McMaster Carr
Step
#
1
Process Description
Cut lower leg to 13” in length
Machine
Band saw
100
Fixtures Tool(s)
N/A
Wood Block
Speed
(RPM)
600
Part Number: ME455-016
Revision Date: 11/5/2013
101
Part Name: Upper Leg (Outer Leg) x 4
Team Name: Special-T
Raw Material Stock: Ferric basic grade 430 steel
McMaster Carr
Step
#
1
2
Process Description
Cut lower leg to 12” in length
Machine
Band saw
Drill one 0.125” dia. hole located
from lower left datum point
X: 0.5”, Y: 0.18”
Drill Press
102
Fixtures Tool(s)
N/A
Wood Block
Vise
Drill Press 0.125”
size Drill Bit
Speed
(RPM)
600
1000
103
Assembly Instructions
In order to create the final product, the following step by step instructions have been provided
with pictures to demonstrate how to assemble it. There are 3 main subassemblies; the lid, kettle
body, and legs. The intention of the design is that the final prototype will be the actual one
distributed to customers.
Lid:
Step 1. Butt-weld four lid sides (3) to top lid surface.
Step 2. Weld Lid Handle (21) to grill lid surface.
Step 3. Place Grill Vent (2) into grill vent hole.
Step 4. Place Thermometer (1) in grill top lid hole indicated by the blue arrow above.
Kettle Body:
Step 5. Butt-weld four Side Plates (10) to kettle base leaving a slot- gap for the Ash Tray (11).
Step 6. Weld leg shims (12) and Leg Hinges (13) at corners where the two tapered corners form
a right triangle.
Step 7. Butt-weld four L-shaped bump-stops (20) to kettle Side Plates (10).
104
Step 8. Butt-weld both Side Plate Handles (19) to the Side Plates (10).
Step 9. Weld Folding Table Hinges (6) to Folding Side Plates (5).
Step 10. Weld other side of Folding Table Hinges (6) to Side Plates (10) above Side Plate
Handles (19).
Step 11. Place Actuating Springs (7) over Actuating Cylinders (8).
Step 12. Place Actuating Cylinders (8) into Side Plates (10).
Step 13. Weld Actuating Cylinders (8) to Actuating Inner Handles (9).
105
Step 14. Run steel wire cables through Side Plates (10) above the Side Plate Handles (19)
through kettle base.
Step 15. Attach steel wire cables to the Actuating Cylinder’s (8) circular flat surface.
Step 16. Place Grill Grates (4) into the kettle body.
Step 17. Weld Ash Tray (11) sides to ash tray base.
Step 18. Weld Ash Tray Handle (18) to Ash Tray (11) and place in bottom drawer of kettle body.
Legs:
Step 19. Place Inner Leg (17) inside Outer Leg (16)
106
Step 20. Place the Locking Buckle (14) mechanism over the Outer Leg (16).
Step 21. Weld Leg Hinges (13) between Inner Leg (17) and Outer Leg (16).
Step 22. Run steel cable from Actuating Cylinders (8) to outward-facing Locking Buckle (14)
attachment holes.
Step 23. Contract Legs for packaging.
Bill of Materials and Cost Considerations
A complete list of the materials needed including purpose, price, supplier and quantity is given in
fig. 15 on pg. 43. The total cost of the materials so far is $318.72. Notice, that some parts still
require supplier quotes to get a more accurate price. Therefore, the final price will indeed most
likely be in the $ 350 – 400 price range.
Cost Analysis: In order to get a realistic idea of the costs associated with the prototype
manufacture, several things were taken into account. The first is obviously the raw materials and
purchased parts price at a total of $400 (worst case scenario). Then the labor was assumed to be
broken into 2 parts; skilled welder and machinist. Welding time was estimated at 8 hours,
machining and assembly at 10 hours, and finishing at 2 hours. Assuming a median labor rate [14]
for both professions (experienced) to be $20, the total labor cost will be $400. The equipment
cost [15] will include $1900 for a mill, $200 for a band saw, $600 for a drill press, $500 for a
MIG welder, and an assumed tool and miscellaneous cost of $500 for things like bits, blades,
safety equipment, etc. Thus the total cost of the prototype is roughly $4500, and a cost
breakdown can be seen below in fig 14.
Fig. 14: Cost breakdown of prototype
Price (USD)
Parts Labor Equipment Total
400
400
3700 4500
107
108
Fig. 15: Bill of Materials for the All-Terrain Grill including part description, quantity, price, supplier and others.
VALIDATION PLAN
In order to validate the proof of concept as a fully functioning, field ready prototype, there were
a series of tests that it had to pass. The main concerns for the A.T.G. were the tests that verified
endurance of the failure modes. Successful completion of these experiments ensured that the
grill would not experience any catastrophic breakdowns during customer use. The failure modes
that compose this category are leg deployment locking (through telescoping lock failure and/or
actual leg material failure), grill collapse through leg hinge failure, grill tip over through
incidental force, and side tray collapse due to hinge or support failure. For all force tests the goal
was to achieve a safety factor of two, as this is appropriate for static free standing structures in
engineering. This safety factor is put in place to both increase the confidence in the product and
to further aid in the prevention of product failure that would put the customer at risk of injury.
Leg Deployment Locking
The keystone failure mode, and therefore most important validation test, was the telescoping leg
collapse. This test that was conducted on the completed proof of concept. The A.T.G. proof of
concept was be placed in 5 different set-up positions.
1. All four legs fully extended on level ground
2. Two of the legs (left or right) on an alternate plane while the other two remain level
3. Two of the legs (front or back) on an alternate plane while the other two remain level
4. One of the four legs on an alternate plane while the other three remain level
5. All four legs level, but on different planes
For each of the set-ups above the weight equivalent of an average U.S. male leaning on the
A.T.G., ~180 pounds will be placed on top of the grill. It was assumed that a person leaning on
grill is ~50% of their bodyweight, therefore full bodyweight is leaning with a safety factor of
two. This test, although the most critical, was conducted last due to the fact that failure would
have cause total destruction of the support system, rendering the proof of concept useless. This
test provided results for both the strength of the legs themselves as well the hinges and
telescoping leg locks. The equipment that was needed for this test were pieces of wood/metal in
order elevate the legs to alternate planes as well as a male of average weight. Almost all of the
design team members fit this criteria so support of an actual human was used in the tests. The
five set-ups above were chosen to try to be as close to “all encompassing” as possible while still
having the quantifiable differences needed for them be measured and evaluated as different test
experiments. The goal was to try and eliminate the possibility of failure in any functional grill
set-up that the customer could potentially come up with.
Tip-over Test
A failure mode that is equally as dangerous, but not as risky as leg collapse is complete grill tipover. Hot charcoal spilling and causing an injury and a fire hazard is the result of both a collapse
and a tip-over, but a tip-over required a sudden impulsive force such as the A.T.G. being bumped
into. The diagram for this test is almost the same as in fig. 18 above, but the applied force is
horizontal to the grill kettle and the down force on the legs is only due to the weight of the grill.
This test used the same five initial set-ups as the leg collapse test, but instead of weight being
applied to the top of the grill, an average male “walked into the grill” from the front/back and
side. In each set-up the grill was bumped into on all four sides to see if tipping would occur.
109
This test was not destructive to the grill because it was not allowed to fall to the ground during
the experiment. If tipping would have started, the grill would’ve been caught by a second
individual and returned to the upright position. The materials for this test were same as the leg
collapse and tipping did not occur in any of the five set-ups.
Grill Set-up/Breakdown Time
The last validation test that was conducted was to ensure grill set-up and stow time were both
less than one minute. This was a fairly simple test that only required a stopwatch and two people
(one to operate the grill and one to operate the stopwatch). With the grill in the fully stowed
position it was timed how long it took to establish it in its fully deployed state, and then again
from fully deployed back to fully stowed. Due the leg deployment unlocking on the proof of
concept possessing intermittent function (legs locked 100% of the time though) the goal of a 1
minute set-up/breakdown time was not met. With minimal improvements to the lock structure
and dimensions this time would be very easily achieved in the mass manufactured model.
No other test experiments were necessary to validate the A.T.G. proof of concept. Shown below
are a small assortment of pictures from the validation testing in figure D.14.
Figure D.14: Pictures of the leg deployment locking validation testing
110
DESIGN RECOMMENDATIONS
Now that the stage of the proof-of-concept development and validation, as well as the business
analysis has been completed, it is imperative to look back and evaluate what went wrong and
what needs to be improved. Before the product reaches the market the design cycle has to be
repeated in order to increase the product’s quality and reliability, and to make it more financially
viable. Often exceeding the initial budget or failure in the validation stage can be beneficial, as
sources of cost-savings and modes of failure that were not so obvious in the planning stage rise
to the surface allowing for significant improvements.
Validation Conclusions & Proposals
Validation proved the strength of some functionality features, while it highlighted the weakness
of others. The subsystems that will be discussed in this section include the leg lock, the locking
actuation mechanism, and the side tables, the spring-loaded pins supporting the cooking grate,
the folding brackets and the feet.
Leg Locks & Telescoping Tubing: The leg lock subsystems were of paramount importance to
the function of the grill as soon as the problem definition and concept down-selection was
complete. Being the All-Terrain Grill, it had four independent telescoping legs that were to be
supported by four separate continuous locks. The big advantage of the A.T.G. is that it does not
lock at discrete segments as most competitive and lateral products in the market do. The locks
did end up working allowing the grill to stand on variable surface. Blocks were used to act as
uneven surface, while weights were added to prove that the total weight that the locks can
withstand is greater than any expected weights. Testing showed that the endurance under high
load was adequate and actually higher than expected. However, the leg lock orientation had to be
changed just prior to the Design Expo, leading to a lack of aesthetics as far as the locks were
concerned. That said, the changed lock design, combined with the low precision tubing
purchased for the proof-of-concept led to failure of the actuation mechanism. That said, aside
from the actuation mechanism which has to be redesigned from scratch, two major
improvements that need to take place are the machining of lower tolerance telescoping legs, so as
to eliminate lateral motion of the lower legs as they slide up and down inside the upper legs, as
well as the change in size of the rectangular slot in the locks to function at really low angles from
the plane horizontal to the ground. This is essentially the way the lock was eventually fabricated.
The modification made by adding an extra piece of metal will now be accounted for.
Lock Actuation Mechanism: Although the legs could be adjusted manually, actuation was not
made possible, because the link of the handles to the locks was ineffective. Combined with the
improvement in the telescoping function by elimination of the lateral wobble, a stronger cable
will enhance the compliance and reliability of the locks with the user’s commands. Kevlar thread
was used, because following the redesign of the leg locks aiming to increase the friction, thicker
cable could not be accommodated by the temporary fix. This change will improve the contact
and behavior of the actuating handles, as the force will be fully transmitted to the locks and will
pivot them to the unlocking position. The new lock design will be composed of a hard stop, an
extension spring, a locking plate, and a guide plate/spring mount.
Side tables: In the case of the side tables, main functionality is achieved as seen in the validation
section. Nevertheless, deflection is observed at the far ends in the case of high concentrated
111
loads. That is not a major problem, because the load will likely be distributed on the area of the
side tables and will vary between cooking utensils, food and beverages. The weight incurred by
such object does not exceed the test load for which the side tables have been validated. However,
fiberglass reinforced plastic is an improvement that is recommended as it will be heat-resistant
and at the same time lighter and cheaper than stainless steel. As there is no direct exposure to
heat on the side tables when cooking, since they are in the open position, and as a result, they
will not melt due to grill use, while at the same time, they will reduce total weight and increase
portability, which is one of the two main product attributes this product aims to satisfy as a
method of differentiation from the rest of the market.
Spring-loaded pins: Full functionality was achieved by the pins. However, as a result of the
inaccuracy of the slots on the sides for the pins, the angle of the pins was not always maintained
perpendicular to the side walls in the proof-of-concept when they were weighed down by the
grate. In the next generation of the product, higher precision holes will be machined. The error in
the proof-of-concept was a result of the low thickness of the sheet steel used and the spring
which had to be fitted perfectly through those holes and still allow motion through the pins. The
next product generation will have pins with a spring mechanism built-in rather than surrounding
the pins.
Folding brackets: The folding brackets in the proof-of-concept version of the All-Terrain Grill
lacked the option to lock at fully collapsed position. Additionally, the fully extended position did
not go beyond the perpendicular to the bottom of the kettle. The substitution of the current
brackets with new hinges allowing the legs to swing from the locked horizontal position to 10
degrees beyond the vertical axis will enhance stability and increase resistance to lateral tip-over
forces id the user happens to be unfocused. That said, in the current version of the product, there
is no mechanism to actuate the folding function of the legs. In the next product generation, not
only will the actuation of the telescoping function be incorporated to the side handles of the
kettle, but also the same actuation will trigger the unfolding of the legs. A first step will involve
adding a pulling guide that will unlock the hinges and under the force of gravity will allow them
to drop and then telescope all the way to the ground from the position held. The weight of the
legs will cause them to lock in the fully unfolded position. A further improvement will involve
actuation from the unfolded position back to the starting position, but that is more complex and
would require heavy mechanisms such as a gearbox and a motor which would increase the
product price and weight. Therefore, minimal user input is only recommended to occur in the
motion from the fully stowed position to the fully deployed position.
Feet: The lower end of the legs when at angle will require the addition of pivoting spring loaded
rubber feet that will allow the legs to contact the ground properly when the legs are at a 10
degree angle to the vertical axis, while the springs embedded in the feet will absorb part of the
ground asymmetry.
Stow position: A final recommendation would be to extend the kettle walls beyond the bottom
to form a lip that would allow the grill to sit flat when legs are fully stowed. That would allow
for use of the grill on a table.
112
Financial Conclusions & Proposals
The cost model in Appendix D shows that the costs associated to the development of the AllTerrain Grill are separated in Material, Manufacturing and Non-Manufacturing categories. The
price was determined to be $100 given the target persona. As a result, the only way to increase
profit margins and accelerate the process of breaking even is to cut down on material and
manufacturing costs, which are estimated at $60.52 and $14.98 respectively. As the economic
batch size rises, manufacturing costs will account for an even smaller proportion of the overall
unit cost. That said, for the required volume of production at the launching stage, certain
improvements could be made to reduce overhead costs.
Thinner Sheet Steel: As a first cost-cutting measure, the next thinnest gauge of sheet steel could
be used instead in order to reduce expenses per unit, since this would minimize mass. It should
be noted, that during validation, the grill was found capable of supporting a male’s total body
weight of 180 lbs., which exceeds the safety factor for anticipated forces exerted on the grill.
Sheet steel thinner than 16 gauge will support the weight of the side tables.
Outsourcing: To create the grill grates, a gravity die cast press and die is needed. Alternatively,
this step could be outsourced and parts purchased, or thin steel rods welded together to form the
grate if the cost is to be further brought down.
Robotic Welding: Most components will be connected with welding, and as such a manual MIG
welder will be needed that can produce the daily volume required. Substitution of manual
welding with an automated process would raise the capital cost but would significantly reduce
labor cost, and would be a preferred process in the next product generation production, given that
volume is anticipated to rise as the target market average user becomes more familiar with this
new product.
113
APPENDIX D
Financial Analysis
114
EXECUTIVE SUMMARY
In order to have a successful product launch, financial factors must be analyzed to determine
viability, and investor requirements. This was done by creating a cost model of the A.T.G., a
profit model with market analysis, a conjoint analysis of the market and products to further refine
price, and a financial forecast to ensure the company always has cash reserves.
The cost model was used to find the total cost to produce the A.T.G., breaking it down by each
part. For parts that are critical and specific to the grill such as the kettle or lid, it was determined
that these should be produced in house as other manufacturers do not readily manufacture them.
For these, the quantity of raw materials needed considering scrap was used in conjunction with
the raw material price to find the total price. For other items, such as fasteners, hinges, and
cables that are produced for many other market products, it was determined that these should be
sourced because the respective manufacturers already have achieved economies of scale in
production that cannot be achieved in house and as such they should be purchased, and this will
be at the lowest possible cost. The total cost of the grill was determined to be $60.52 including
other costs such as sales, marketing, and stocking. This could be further reduced by using thinner
sheet steel or negotiations with suppliers. Manufacturing costs were determined by selecting the
appropriate methods such as sheet stamping and die casting for parts based on selection indices
found in CES [D.7] taking into account the material, economic batch size and tooling costs.
Overhead was estimated in similar fashion, as well as labor rates based on statistics from [D.1].
The total manufacturing cost is $14.98. Additional costs from sales, marketing, distribution and
general office overhead bring the grand total to $86.82. With a sale price of $100, as determined
through a variety of factors to be appropriate, there will be 15% profit per unit.
A profit model was created to come up with an initial guess of a sale price for the grill. To do
this, the overall grill market was analyzed and estimated to be at just under a million units. Sales
data for individual competitors was collected if possible, and estimated in other cases. With an
initial market share goal of 2% increasing to 4%, the A.T.G. should sell 20,000 units at first and
40,000 in 5 years. From the sales data, a general demand curve was determined and used in a
more complex demand curve taking into account the cooking area and grill height at weights of
60 and 40 percent respectively. These characteristics were optimized to produce the maximum
profit, but due to irregularities and the fact the near optimal settings were already achieved, a
basic profit model was used. From this model it was determined that in order to maximize profit
the sale price should be $200, far in excess of what the market would allow as seen in the other
sections and through sound judgment. For these reasons, the results of the profit model were
studied but not used as they are flawed presently. Further analysis could potentially remedy this,
but at this time all other pricing tools are more accurate and will be used.
The most meaningful market pricing strategy data came from the conjoint analysis. This was
based on survey results from potential consumers and analysis software from Sawtooth. In the
analysis, the characteristics studied were grill price with attributes of $50, $100, and $150,
cooking capacity with attributes of 2-4 people, 4-8, people, and 8 or more, and relative storage
size of small, medium and large. The partworth of each attribute was determined and the most
preferred combination would be a price of $50, with capacity for 8 or more people, and a small
stored size. From this, the relative importance of each characteristic was determined, in
descending order, to be storage size, price, and capacity. Following this, a simulation was run to
115
put the A.T.G. up against the Kingsford and Coleman portable grills to help determine an
appropriate price and the potential market share. With the A.T.G. at a price of $100, capacity for
8 or more, and medium storage size the market share was at its most reasonable, at 34.6% with
the Kingsford at 28.7%, the Coleman at 24.8% and none of these at 11.9%. This data indicated
that the design choices made in the grill were in fact right on target and that the ideal price to sell
is $100 as previously estimated in the cost model. For these reasons, the grill will be sold for
$100 a unit at a 15% profit, and the design is considered feasible for market entry.
With a fully validated and working design that can be profitable, the overall financials of the
business were evaluated to determine overall business viability. A discounted cash flow analysis
was conducted, with equipment, tooling and startup costs at $517,000, and the number of units to
be produced as mentioned prior. The internal rate of return was found to be 39.4%, and the
business should break even within 2.8 years, or the 4th quarter of the 2nd year. This has been
represented in both table and graphical format for ease of reference. Additionally, a cash flow
accounting statement was prepared for the first 3 years to prevent any deficiencies, mitigate risk
of default, and determine initial investment needs. Here rent was assumed based on building size
to be $20,000 per year, manufacturing and material costs were from prior calculations, and salary
and benefits totaled $100,000 for each of the 5 individuals operating the company. With no
personal investment, and a small business loan at 14% APR, an investment of $700,000 will
keep the cash flow positive. This setup has the lowest balance occur 10 months after startup with
a reserve of $20,000. This should be reasonable since it is roughly 10% of monthly expenses. To
mitigate risks such as supplier issues or decrease in sales, a higher upfront investment could be
sought, more borrowed from the bank, or from the individual contributors. However, once this
point is reached, despite still not breaking even, the cash flows become positive and the company
should be safe from a cash on hand perspective.
Overall, the financial analysis completed in the form of cost modeling, profit modeling, conjoint
analysis, and financial forecasting indicate that the A.T.G. is a viable product and business
venture. With an initial investment of $700,000 and a sale price of $100, the grill can compete
strongly against and perhaps even exceed projected sales volume, which are conservative in
nature. In addition to being a viable product and business, the results validate the design as a
whole.
COST MODEL
In order to provide a reasonable product that would be successful in the market, an assessment of
the financials of the cost of materials and manufacturing for the final product are needed. Not
only will they allow a final price to be determined, but also provide insight into profit, room for
improvement in terms of design and manufacture, as well as a better understanding of the needs
of the business.
Material Costs
When pricing out materials, several factors were taken into account. The results can be seen in
section A of table D.1 For some critical components that would not be possible to source, or
more costly than could be produced in house, materials were determined by the dimensions
needed for the process and assuming 20% scrap material. From this a volume of sheet metal was
determined, multiplied by the density from [D.7] and then multiplied by the price per kg from
116
[D.6]. The processes selected to form these materials was chosen through analysis in [D.7]
focusing on the economic batch size, and process capabilities for the material and desired shape.
Most other parts such as springs, fasteners, hinges and legs were selected to be sourced because
those manufacturers produce significantly higher volume than needed for the A.T.G. and as such
will be available at a cost less than in house production. Overall, materials were chosen for
strength and durability while trying to minimize mass, in the future, it could be considered to use
the next thinnest gage of sheet steel as a cost cutting measure if deemed necessary after market
entry.
Table D.1: Total Cost Breakdown of the A.T.G. with materials (A), manufacturing (B), and other
(C) costs and the final price (D) with suggested retail price and profit.
A. MATERIAL COSTS
# Part
1
2
3
4
5
Qty Description
heavy duty analog readout
turn to allow airflow
cover food, sit on grill grate
support food and charcoal
support misc. items, serve as top
when stored
180 degree rotation
return pins to rest position
suport grill grate
steel
galvanized sheet steel
galvanized sheet steel
coated steel
galvanized sheet steel
Wt
(kg)
0
0.25
4
0.45
1.5
stainless steel
stainless steel
aluminum
0.1 McMaster Carr
0 McMaster Carr
0.35 McMaster Carr
n/a
n/a
$ 1.70
$4.00
$2.00
$2.38
8
8
7
weld
weld
cut, thread
plastic
galvanized sheet steel
0.15 McMaster Carr
6.00 manufacture
$ 1.70
0.5
$0.51
$3.00
8
1
atach to springs, pins
stamp
1
4
4
4
4
4
release locks, pins
house assemby when stored, main
grill body
collect ash, hold charcoal grate
pivot locking mechanism
support grill, telescope
support grill, fold
spring loaded
friction lock
stainless steel
coated steel
stainless steel
stainless steel
brass coated steel
galvanized sheet steel
3.2
0.1
0.5
0.5
0.2
0.1
manufacture
McMaster Carr
Alro
Alro
hardware store
manufacture
$ 1.50
n/a
n/a
n/a
n/a
$ 0.50
$4.80
$12.00
$2.00
$2.40
$12.00
$0.20
3
8
6
6
7,8
7,8
stamp
weld
cut
cut
cut, weld
cut, weld
1
4
8 feet long
angle stock
sheet steel
0.1
0.5
Alro
purchase
n/a
n/a
$2.00
$2.00
7
4, 8
cut, route
stamp, weld
4
4
rounded, dark stain, 2 piece design
sheet steel
oak
0.2
1
manufacture
manufacture
$ 0.50
$ 0.50
$0.40
$2.00
4,8
10
stamp, weld
screw in
1
2
standard universal level
locking for folding trays
plastic
0 McMaster Carr
n/a
stainless steel
0.75 McMaster Carr
$ 1.50
Total Weight (kg): 20 Total Material Cost:
$0.50
$2.25
$60.52
10
10
attach
attach
Tooling/ Ded Cap
Costs
Thermometer
Grill Vent
Grill Lid
Grill Grate
Side Table
1
1
1
2
2
6 Table Hinge
7 Actuator Spring
8 Grill Support Slide
Pin
9 Actuation Handle
10 Grill Kettle
2
4
4
11
12
13
14
15
16
Ash Tray
Leg Hinge
Inner Leg
Outer Leg
Locking Hinge
Locking Mechanism
17 Steel Braided Wire
18 side tray support
braket
19 handle
20 Wooden Handle
Cover
21 level
22 buckle latches
2
1
Material
Supplier or
Manufactured
McMaster Carr
manufacture
manufacture
manufacture
manufacture
mat.
cost/kg
n/a
$0.500
$0.500
$0.500
$0.500
Cost
Oper Ref #
Operation
$2.00
$0.13
$2.00
$0.45
$1.50
10
7
2
5
7
insert
cut
stamp
cast
cut out
B. MANUFACTURING COSTS
#
Operation
Machine Description
1
2
3
4
5
6
7
8
Stamp Kettle
Stamp Lid
Stamp Ash Tray
Stamp Handles, supports
Cast Grill Grates
cut tables, vent
spot weld handles,
cut and laquer wood
handles
9
Final Assembly
sheet steel stamping press
sheet steel stamping press
sheet steel stamping press
sheet steel stamping press
gravity die cast
plasma cutter
mig welder
wood lathe, dunk tank
Two assembly stations with work
table, assembly fixture
10 Finishing, Final Inspection Two stations with work table,
inspection equipment
Fixed and Variable
Overhead ($/hr)
Cycle Time (s)
Operation
Total Cost
$150
$150
$150
$150
$200
$100
$100
$75
Direct
Labor
($/hr)
$18.00
$18.00
$18.00
$18.00
$18.00
$18.00
$20.00
$15.00
30
30
30
30
30
30
120
60
$1.40
$1.40
$1.40
$1.40
$1.82
$0.98
$4.00
$1.50
Machine
and Eqmt
Costs
$100,000
$0
$0
$0
$150,000
$15,000
$10,000
$2,000
$50
$15.00
30
$0.54
$25,000
$10,000
$50
$15.00
30
$0.54
$25,000
$0
Total Manufacturing Cost:
$14.98
$327,000
$90,000
Total Material and Manufacturing:
$75.50
C. NON-MANUFACTURING COSTS
Sales Commission, Distribution, and General Administration (10%)
Other (5%)
$7.55
$3.77
Total Product Cost:
D. PROFIT
15%
$86.82
$13.18
TOTAL SELL PRICE
117
$100.00
$25,000
$15,000
$10,000
$5,000
$25,000
$0
$0
$0
Manufacturing Costs
In order to build the ATG, many fabrication steps will be performed in –house as well as
assembly and final inspection. See table D.1 for manufacturing cost breakdown. A medium sized
sheet steel stamping machine will be required with several interchangeable tooling for the kettle,
lid, ash tray, handles, and tray supports. Machinery on site will also be needed for steel cutting,
as well as the ability to cut other materials. A plasma cutter, saws, a drill press, hand tools and
grinding equipment will suffice for most other random needs. To create the grill grates, a gravity
die cast press and die will be needed. Alternatively, this step could be outsourced and parts
purchased, or thin steel rods welded together to form the grate if the cost is to be further brought
down. In order to make the wooden handles, a wood lathe will be needed and equipment to apply
the lacquer and coating. Simple drilling machinery will be needed for making holes such as a
drill press or cordless drills. Most components will be connected with welding, and as such a
manual MIG welder will be needed that can produce the daily volume required. For now the
process will be manually operated, but may at a later point be switched over to an automated
process. Some components may require a spray coating that is heat resistant and as such a
painting area will be needed with proper ventilation. Following this, final assembly will take
place in dedicated work areas where the previously made components can be combined, and
secured together as needed. Once assembled, all units will be inspected for defects and to ensure
proper operation before packaging. All of these steps with associated labor, overhead, tooling,
and other costs is listen in section B of table D.1.Labor was assumed to be mid-level skilled for
trades work and labor was taken rates were determined from the US Bureau of Labor Statistics
[D.1]. A floor space of approximately 4-5 thousand square feet will be needed to house this as
well as offices, warehousing, and all other things necessary for the operation. Annual rent for this
should run around 20 thousand dollars.
Other Costs and Suggested Retail Price
Other costs not included prior are compensation for sales, commission, office equipment and
administrative costs as well as others. This was done as a percentage of the total product cost and
can be seen in section C of table D.1 Labor costs for the entrepreneur and further breakdown can
be seen in the financial forecasting section. Notice a final profit around 15% with a chosen sale
price of $100. This value was determined by balancing the results of market research, the
conjoint analysis, examining the profit model and balancing it with good judgment.
PROFIT MODEL
In order to get a rough estimate of the demand, and potential price of the A.T.G., a preliminary
investigation was conducted into the portable grill market that was used to create a profit model.
This basic profit model was refined on some key factors that were assumed to affect price
118
The Market
Investigations were made into the market size in terms of annual unit sales for portable grill, in
which the A.T.G. might belong. Since this data was not readily available, some assumptions
were made based of information found. Since 6.25 million grills are sold annually [D.3], and
roughly 15% of the adult population goes camping [D.4] a market size of 900,000 was
determined. Some key competitors were analyzed to try and find their market share. In the case
of Weber, an industry report on portable charcoal grill sales by dollars was made, the number of
units was inferred from the average price and found to be roughly 33% of the assumed market.
Data from Kingsford and Coleman was not found, and requests for information were not
satisfied due to company privacy concerns or lack of data. Therefore, the remaining allocation
percentage of each competitor was assumed based on customer reviews, prevalence in
stores/online, and perceived brand reputation with Kingsford having 21% market share, and
Coleman with 16%. Also, a target was set for the A.T.G. to start at 2% of this market and move
to 4% or roughly 40,000 units, as used in following sections. The market share results can be
seen in fig. D.1 with the un-allotted market attributed to either other producers, error, or unmet
demand.
Fig. D.2: Simple grill market demand
function showing price and units
Fig. D.1: Portable grill market segmentation
with the A.T.G. at a target of 4%
Weber
Demand
Function
Kingsford
Coleman
Profit Modeling
Using the sales data assumed prior, a market demand curve was created by plotting the price of
each competitor product and its assumed sales volume seen in fig. D.2. From this data, a
regression was done to find the formula to describe demand that was used to construct the grill
profit model. Additionally, a further refined demand function was used to determine the quantity
demanded at a variety of potential prices. This formula is seen in eq. D.1 where θ is the y
intersect of the simple demand regression, λP is the slope of said regression, and λd is the
changed parameters weight multiplied by the change in the parameter, Δα, they represent. The
two values are the assigned importance of the factors to be optimized: cooking area and height
with weights of 60 and 40 % respectively, and changes were made to each independently from
the reference dimensions of the designed product. It was found that an increase in cooking area
or height each generated more demand but at a higher cost and therefore the simple demand
model neglecting these factors was used.
119
Fig. D.3: Profit model showing an unusual trend, with
maximum profit at a grill price of $200.
Eq. D.1: Equation for demand with
weighted factors taken into account
Max Profit $200
The profit model is simply the total revenue (demand times price) and costs, including fixed and
variable with demand determined as previously described. The profit model is seen in fig. D.3,
with a maximum profit occurring at a sell price around $200. This does not agree with other
analysis methods and good judgment from the group’s experience. The reasoning for this is due
to the fact that there was incomplete market data. Without exact figures and all the competitors
the total volume was one third the assumed sales prior. Also, inaccuracies in the assumed sold
units when data was not available could significantly alter the slope of the demand curve. For
these reasons, the results of the profit model were studied but not used as they are flawed
presently. Further analysis could potentially remedy this, but at this time all other pricing tools
are more accurate and will be used.
CONJOINT ANALYSIS
In order to further refine the price determined in the profit model section, which is based on
competitor and market sales trends as well as key characteristics, a conjoint analysis was
conducted which takes into account potential customer opinions to determine the importance of
key characteristics and purchase preference. To do this, a survey was conducted online using
Sawtooth Software®, and the results were used for analysis.
Importance of Key Parameters
In the survey, three main attributes were chosen to be analyzed and included the grill price,
stored size, and cooking capacity. Three distinct levels, or attributes, of each value were offered
and the software determined through a variety of questions the relative utility, or partworth, of
each attribute as well as the relative importance of the price, storage size and cooking capacity.
The partworth of each attribute are seen in fig. D.4 in order of price, cooking capacity and
storage size. Notice that for price, the three levels included $50, $100, and $150 with preference
for the lowest price. This indicated that the price point from the profit model was far too high,
confirming intuitive results. Thus it would seem the $100 price point a good target for the
120
A.T.G.. For cooking capacity, the three levels are capacity for: 2-4 people, 4-8 people, and 8 or
more. Here preference is again for more cooking capacity, but the preference is not as steep as
that of price. The A.T.G. possesses this greater cooking capacity.
Fig. D.4: Partworth of grill price, cooking capacity, and stored size. Higher values indicate a
more preferred attribute. Here, a price of $50 with capacity for 8 or more people and small stored
size is preferred to the respective alternatives.
From the partworth of each characteristic, the overall importance can be determined and is
shown in fig. D.5. Notice that the most important characteristic is the storage size at 39/7%,
followed by the price at 33.3%, and then the cooking capacity at 27.1%. This would seem like a
rational result for a portable grill, since in order to be transported and stored it should be
relatively small, then price is always an object, and lastly the consumer still wants to cook for
many people. However, this survey is slightly at odds with the original market survey in which
consumers expressed a greater preference in cooking capacity. This discrepancy is most likely
because in the prior survey the customers were not forced to choose between features.
Fig. D.5: Relative importance of key grill characteristics showing that the order
of importance to the consumer is stored size, price, and then cooking capacity.
121
Market Share
Using the partworth data, the software was able to simulate potential user preference among
possible grills. For comparison the A.T.G. (with a cooking capacity for 8 or more, price of $100,
and medium storage size) was put up against the Coleman Roadtrip [D.5] (with a cooking
capacity of 4-8, price around $100, and also medium storage size) and the Kingsford Portable
grill [D.9] (with cooking capacity of 2-4, price around $50, and medium storage size because it is
small but doesn’t collapse). The results of the simulation can be seen in fig. D.6 showing
customer preference indicating that the A.T.G. would potentially have 34.6% of the market,
while the Kingsford would have 28.7%, the Coleman 24.8% and 11.9% would choose none. By
changing combinations, other possibilities can be seen and this was used to help determine price
since the other features had already been set. It is apparent that the initial price of the A.T.G.
should be set to $100 and the results also confirm the design choices made. This confirms that
focusing on cooking capacity and trying to minimize size as well as make the grill highly
portable and adaptable to a variety of terrain was indeed the right market strategy. In review, the
partworth of key selected attributes were intuitively chosen in the design stages and those
choices were validated through the partworth analysis of a market survey. The A.T.G. as a whole
was also validated as a viable product from the customer preference simulation.
Fig. D.6: Results of conjoint analysis simulation show consumers prefer the A.T.G. over the
Coleman Roadtrip and Kingsford Portable Charcoal Grill.
Conjoint Analysis Showing Market Share
FINANCIAL FORECAST
Prior analysis has shown that the A.T.G. is a viable product for the market, and financial
calculations developed and presented within this section show that the business of producing,
marketing, and selling these will be a profitable endeavor. This was done by generating a
discounted cash flow analysis to determine how much investment is needed, the break-even
point, as well as other critical financial data.
Discounted Cash Flow
The results of the discounted cash flow analysis conducted for the A.T.G. can be seen in table
D.2. This examines the flow of money in and out of the business and accounts for the discounted
122
value of future earnings with an assumed discount rate of 15%. Notice the initial tooling, launch,
and equipment costs of $517,000 as previously determined with an assumed launch cost of
$100,000. An assumed tax rate of 37% was used. Additionally, production was assumed to
increase by 5000 units each year starting at 20,000 and ending at 40,000. From the report, the
internal rate of return was determined to be 39.4%. Additionally, the enterprise will break even
in 2.83 years, or the third quarter of the 2nd year. The information from this analysis was used to
construct the profitability chart seen in fig. D.7 showing the initial investment at startup as
mentioned prior, the profit, and net cash flow on an annual basis.
Table D.2: Discounted cash flow analysis
Discounted Cash Flow Analysis
Project Year
Calendar Year
0
2014
1
2015
Start of Prod
2
2016
3
2017
4
2018
5
2019
TOTAL
Investment
Equipment/Capital Exp (7 Yr Life)
Tooling/Ded Capital (3 Yr Life)
Launch Costs (Prod Trials, etc.)
$ (327,000)
$ (90,000)
$ (100,000)
$
$
$
(327,000)
(90,000)
(100,000)
Total Investment
$ (517,000)
$
(517,000)
20,000
1 SHIFT/DAY
25,000
30,000
Revenue
Price/Pc
$100.00
$ 2,000,000
$ 2,500,000
$ 3,000,000
Cost of Goods Sold
Cost/Pc
$86.82
$ (1,736,462) $ (2,170,577) $ (2,604,693) $ (3,038,808) $ (3,472,923) $ (13,023,463)
Profit
Prof/Pc
$13.18
$
263,538 $
Tax
Tax Rate
37.0%
$
(97,509) $ (121,886) $ (146,264) $ (170,641) $ (195,018) $
$
$
$
$
166,029
(76,714)
89,315
28,388
Unit Volume Projections
After-Tax Profit W/O Depreciation
Book Depreciation
After-Tax Profit W/Depreciation
Tax Savings from Depreciation
Total Cash Flow
Present Value Discount Factor
Net Present Value
Internal Rate of Return
Breakeven/Payback Period (yrs)
Product EBITDA/Gross Margin
$ (517,000) $
15%
$ (517,000) $
$
$
$
$
194,418 $
0.8696
329,423 $
207,536
(76,714)
130,822
44,432
$
$
$
$
251,969 $
0.7561
169,059 $
39.4%
2.83
13.2%
123
190,525 $
2 SHIFTS/DAY
35,000
40,000
$ 3,500,000
395,308 $
249,044
(76,714)
172,329
26,093
$
$
$
$
275,137 $
0.6575
180,907 $
$ 4,000,000
461,192 $
290,551
(46,714)
243,837
17,579
150,000
$ 15,000,000
527,077 $ 1,976,538
(731,319)
$
$
$
$
332,058
(46,714)
285,344
10,804
$ 1,245,219
$ (323,571)
$
921,647
$
127,297
308,130 $
342,863
$
855,516
$
370,128
0.5718
176,174 $
0.4972
170,463
Fig. D.7: Profitability chart showing the initial investment for machinery, the annual profit and
net cash flow indicating a break-even point after 2.8 years
Break Even:
2.82 yrs.
Cash Balance
In order to ensure the company doesn’t go into the red during production and despite making a
profit, a pro forma accounting statement was constructed. It takes input from the previous
discounted cash flow, but adds things like rent, staff compensation, loan and other payments and
can be seen in table D.3. For the statement, no personal investment was assumed, an annual rent
of $20,000 assumed to include utilities and such, and a salary of $100,000 to each of the 5 people
on the team (including healthcare and benefit costs) designated. Additionally, a small business
loan of $500,000 with 14% APR was assumed. From the resulting cash flow, it was found than
in investor contribution of at least $700,000 is needed to maintain a positive cash balance. The
resulting cash balance over a 3 year period can be seen in fig. D.8 and shows the lowest cash
balance occurs 10 months after operation begins and is roughly $20,000. While the product does
make a profit the entire time, it is only before this that it does not exceed payments going out.
After this point, despite not yet breaking even, until year 3, the company will have sufficient
cash reserves to ward off any issues that might arise such as supplier cost increases, decreased
sales, labor demand increases etc. To mitigate the risks, it is wise to keep a sizeable amount of
cash on hand and the investor contribution covers this. If more of a safety barrier were desired, a
greater initial investment would cover this. In the event of said occurrences, other measures can
be taken to preserve financial integrity including paying salaried employees less, renegotiating
bank loan terms or asking for more investment capital.
124
Table D.3: Proforma calculations used to generate cash flow information. From this the initial
investor contribution to be asked for and business loan were adjusted to prevent any periods
without sufficient capital on hand.
Proforma: First Three Years By Quarters
Project Year
Calendar Year
Project Quarter
Calendar Quarter
Qty Sold
0
2014
0.00
Jan-14
0
Qtrly Cash Balance
Running Cash Balance
2
2016
3
2017
0.25
Apr-14
0
0.50
Jul-14
0
0.75
Oct-14
0
1.00
Jan-15
5,000
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$129,250
$129,250
$129,250
$129,250
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$5,000
$5,000
$5,000
$5,000
$5,000
$5,000
$5,000
$5,000
$5,000
$5,000
$5,000
$5,000
$5,000
$5,000
$5,000
$5,000
Income
Initial Personal Investment
$0
Investor Contributions
$700,000
Small Bus Loan (Wrkg Capital) $500,000
Product Revenue
$0
Total Income
$1,200,000
Expenses
Eqmt and Launch Investment
Bldg (Plant + Office) Rent
Mat'l and Mfg Costs
Salaried Staff Compensation
Loan Payment
Total Expenses
1
2015
1.25
1.50
Apr-15 Jul-15
5,000
5,000
1.75
Oct-15
5,000
2.00
Jan-16
6,250
2.25
Apr-16
6,250
2.50
Jul-16
6,250
2.75
Oct-16
6,250
3.00
Jan-17
7,500
3.25
Apr-17
7,500
3.50
Jul-17
7,500
3.75
Oct-17
7,500
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$500,000 $500,000
$500,000
$500,000
$625,000
$625,000
$625,000
$625,000
$750,000
$750,000
$750,000
$750,000
$500,000 $500,000
$500,000
$500,000
$625,000
$625,000
$625,000
$625,000
$750,000
$750,000
$750,000
$750,000
$0
$0
$0
$74,917
$74,917
$74,917
$74,917
$93,646
$93,646
$93,646
$93,646
$112,375
$112,375
$112,375
$112,375
$0
$125,000
$125,000
$125,000
$125,000
$125,000 $125,000
$125,000
$125,000
$125,000
$125,000
$125,000
$125,000
$125,000
$125,000
$125,000
$125,000
$17,486
$17,486
$17,486
$17,486
$17,486
$17,486
$17,486
$17,486
$17,486
$17,486
$17,486
$17,486
$17,486
$17,486
$17,486
$17,486
$276,736
$276,736
$276,736
$351,653
$222,403 $222,403
$222,403
$241,132
$241,132
$241,132
$241,132
$259,861
$259,861
$259,861
$259,861
$147,486
$923,264
-$276,736 -$276,736
-$351,653 $277,597 $277,597
$277,597
$258,868
$383,868
$383,868
$383,868
$365,139
$490,139
$490,139
$490,139
$602,514
$923,264
$646,528
$369,792
$18,139
$295,736 $573,334
$850,931 $1,109,799 $1,493,667 $1,877,535 $2,261,403 $2,626,542 $3,116,681 $3,606,820 $4,096,959 $4,699,473
Fig. D.8: Cash flow for the first three quarters of operation indicating the lowest point will occur
in October 2014 with around $20,000 in reserve.
125
APPENDIX E
Information Sources
126
APPENDIX A RFERENCES
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127
APPENDIX B REFERNCES
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128
APPENDIX C REFERNCES
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[C.3] Gizmag. Pull and Push door concept makes coming and going a lot easier. Accessed
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129
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130
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ADDITIONAL RESOURCES USED FOR PRODUCT RESEARCH
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[8] http://www.tablefeet.com.au/
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http://www.kingmetals.com/Catalog/ItemContent.aspx?ItemNumber=8842&CatalogId=C39&Ca
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[13] http://www.grillgrate.com/
[14] http://www.charbroil.com/replacement-parts/grids-grates.html
[15] http://www.lowes.com/Grills-Outdoor-Cooking/Grill-Parts/Grill-Cooking-Grates-WarmingRacks/_/N-1z0ye8b/pl
131
[16] http://www.househandle.com/
[17] http://www.allpartsgrills.net/grill-parts/Grill-Parts/Grill-Handles.htm
[18] http://www.bbqguys.com/category_path_2152.html
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[21] http://www.campingworld.com/category/levels/574
[22] http://www.bestbuy.com/site/sunpak-2-way-bubble-level
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[27] http://www.sears.com/shc/s/t_10153_12605?tName=flexible-braided-steel-cable.html
[28] http://www.weber.com/grills/category/charcoal
132