More Related Content Similar to ZiemkeDesignPortfolio Similar to ZiemkeDesignPortfolio (20) 1.
The HumanPowered Vehicle Portfolio
Design Portfolio for ENGR 232
By: Name
Section 1, Team 2, Engineering Unlimited: Scott Stone, Max Painley, Jacob Ziemke, Joe
Kellum, Zach Pacifico, Steven Austin Underhill, Nick Vaisa, Tyler Jarrett, Evan Norman
Contents
Introduction………………………………….…………………..1
Importance and Impacts…………………………………………1
Design Tools and Methods…………………………….………..2
Results and Justification……………………………….………..5
Design Decisions………….…………………………….…...….6
Reflection……………………………………………….……….8
Accountability Report………………………………….………..10
Future Work………………………………………………….….12
References and Appendices………….…….………....….……...13
2. TO: James Madison Engineering
CC: ABET
FROM: Engineering Unlimited NAME
SUBJECT: Design Portfolio
DATE: May 1, 2015
__________________________________________________________________________
Introduction
One of the thrills of childhood is having the freedom that a bicycle allows, having the ability to
get around without the help of adults. A bike is more than just some exercise, it is being able to
go to a friends house easily, or going on new adventures with siblings or friends. This semester’s
goal was to complete a bike for the team’s client that would allow him this freedom.
Our client suffers from a form of cerebral palsy called spastic hemiplegia. This condition causes
certain muscles on mainly the left side of his body to be in a constant state of contraction. This
reduces his range of motion and leaves opposing muscle groups weaker, limiting his ability to
partake in some activities that other children are capable of participating in. Throughout these
two semesters Engineering Unlimited has been designing and refining ideas to accommodate the
client’s needs to allow him this freedom. modate
Importance & Impacts
This type of project holds a special place in the heart of the Harrisonburg community. The
sophomore design students of James Madison University’s engineering program have been
designing unique vehicles for local residents for over 5 years. The tradition began when students
built a vehicle for Dr. Thomas Moran, a JMU professor with Cerebral Palsy. Like Dr. Moran, the
current client is also limited in riding a bike, which is a staple in almost everyone’s childhood. A
bike gives children a form of independence and freedom. They have to rely on their own ability
and skill to ride, sometimes without the supervision of their parents. The team hopes to enable
Michael to participate in this activity with other children and to give him a sense of
independence by providing him with a human powered vehicle that accommodates his disability.
Michael is not the only one who will benefit from the vehicle we intend to design. His mother,
Michelle, wants to see him achieve more than he already has. She wants him to continue to push
himself and exercise the muscles in his body that need to be strengthened. Seeing her son happy
is important to her. The team wants to help her develop Michael into a strong, independent boy.
1
3. Michael and his family are a part of the Harrisonburg community, where Madison Engineering
students continue to make impacts by building specialized bicycles and performing other
projects. Madison Engineering students take great pride in working among Harrisonburg and its
residents and improving lives through the field of Engineering.
Team Formation:
Before beginning the project it was imperative to create a team atmosphere inducive of hard
work and collaboration. Most of the members didn’t know each other so we decided it would
benefit us to figure out who was going to be good at what. We had to chose positions for
ourselves. To do this we each chose our three top positions that we believed we would be good
at. We then talked about why we would be good at those until each member came to consensus
about which job they could handle and which team orientation would be best for us. We realized
that having a central leader would be ideal to get all information in one place so that everyone
could get it without having to ask everyone. After that we decided that all other positions should
be considered equal. So our team orientation ended up looking more like the wheel orientation.
The team also talked about what was expected of each member, what days we would come in to
work weekly, and set up an attendance policy system. This discussion allowed the team to
become acquainted and to set the team in a direction to complete our assignments quickly and
with equal shares of responsibility. This ended up being very beneficial in the long run as we had
very little tension and got all our work done in a timely and fair manner.
Methods
In order to complete this project to the best of the team’s ability, a strict design process was
needed to keep efficiency and work quality in check. These chronological steps not only helped
to keep the team on task, but told the story of the design process that took place, from the
beginning problem statement to the final design. The methods used to complete the human
powered vehicle for the client are as follows:
Pugh Chart: (Figure 2)
In order to decide on a final design, the team compared each individual’s design solutions using
a pugh chart. In a pugh chart, different designs are compared to a single design, or datum, in
several different categories. They are ranked with a +1, 0, or 1, depending on whether the design
was better than, the same as, or worse than the datum in that particular category. The criteria
used to compare each design included propulsion, steering, braking, weight, safety, ease of
operation, stability, cost, and aesthetics. The team chose to use Max and Jacob’s design solution
as the datum to compare everyone else’s design to.
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4. Decision Matrix: (Figure 3 & 4)
Once the comparisons using the Pugh Chart were finished, the four designs with the highest total
ranking were then compared in much higher detail using a decision matrix. A decision matrix is
similar to a pugh chart in that it compares designs using certain criteria. The difference is that
each criteria is weighted depending on their relative importance. The criteria used in the decision
matrix were the same as those of the pugh chart. This matrix allowed the team to also compare
past designs to a new, iterated design, and then make a decision on which design to follow.
Proof of Concepts and Back of the Envelope Calculations: (Figure 6 8)
In order to understand if and how the subsystems of this new design would work, very
rudimentary models were created. These models allowed us to understand the actual function of
each part and where the pain points may be in that system. We created proof of concept models
for the structural, propulsion, steering/braking, and safety. This task was approached by seeking
a way to demonstrate the key functions of the system and prove that they work. For the
propulsion system, a 6x2 beam of wood was cut with a few grooves to allow a crank to slide into
it. This was used to check that Michael was actually able to pedal a rotating crank and how high
it should be mounted for optimal efficiency. For the structure, stiff wire was soldered together to
create a model structure. This was used to demonstrate the shape of the chassis and how the rest
of the components would fit on it. The steering and braking system was represented by a three
wheel wooden replica of a scooter that used a universal steering joint similar to the one needed
for the real design. This was meant to model the wheelbase and how the system would steer as
well as how the input and output of the steering were independent, allowing for adjustability of
the steering column. For the safety system, a bucket seat and a foot pad were built to model the
added caution designed into the pieces holding Michael secure. For each subsystem it was also
necessary to gain an understanding of how well these subsystems would work and how much
impact they would have on the overall characteristics of the vehicle. To do this the team
computed back of the envelope calculations to define at least an estimation on how much the
object would weigh and how much space it would take up. This required individuals to estimate
the length, width and height of each material. Then the weight of each material and system was
either computed by the research of material density or guessed based on scale measurements and
observations.
CAD Modeling: (Figure 9)
Once there was an idea of how the various subsystems of our human powered vehicle would
look and work together in the overall system, threedimensional modeling needed to be
completed. This process began with engineering drawings that were completed to ASME
standards. These engineering drawing included two subsystems together in order to show the
intended measurements and plan for the integration of those subsystems. These drawings
allowed us to begin working into CAD modeling using the SolidWorks software. Each member
3
5. of the group was responsible for modeling a subsystem in SolidWorks. The final subsystems and
parts were compiled into an assembly, which was the final representation of the bike to scale.
This gave us an idea of the amount of materials needed as well as offer other statistical analyses
tools.
Bill of Materials: (Figure 10 & 11)
After establishing what the various subsystems for our human powered vehicle consisted of, we
completed a list of all the parts we needed for the vehicle. This bill of materials needed to
coincide with all the parts listed in the CAD assembly. After finishing a list of needed parts, we
researched which parts could be bought and which parts we were able to be scavenge from other
past vehicles made available to us by the JMU engineering department. For the items that we
planned to purchase, we created a budget to see how much money would be spent on the bulk of
our materials. After determining the cost estimation for the materials needed, we estimated the
cost of labor based on the estimated material cost and manhours needed to complete the vehicle.
Frame and Center of Mass Analyses: (Figure 12 16)
After weeks of planning and reiterating the team came to a final design. Measurements of the
client’s proportions were taken and compiled so that we could put measurements to our vehicle.
We were then given the task of using this data and our design to find the center of mass of our
bike. This could help us understand how safe our client would be going around turns or
experiencing any shift in weight. To do this we took the mass measurements of all the larger
objects, such as wheels, the seat, and the cradle and calculated the moments caused at the rear
axle. We chose the rear axle because it cancels out the most external forces. Once all the
moments of the parts were calculated they were added up and divided by the sum of the masses
of the parts. THis gave us the location of the center of mass however that is only in one place.
This calculation had to be done three times each in the respective planes of X, Y, and Z. Through
this process we came to the conclusion that the center of mass was 23in from the rear axle in the
forward direction, 13in above the rear axle, and directly in the center of the rear axle. Using these
we could later calculate the tipping point of the bike in our prototype testing.
Understanding Impact: (Figure 16 18)
Impact is the economic, social, and environmental effects that each material presents in the
formation of the material. After determining what materials were going to be present in our
vehicle’s design we then split into three groups of three to analyze the impact of each material.
The three materials that were researched were plastic, rubber, and polypropylene. The three
teams were tasked to look up the estimated life in use of each material, the time it would take to
decompose, and the specific ways in which the material would impact all of its environments.
For instance how it might cause bodily harm if ingested. After researching the impact of each
material, the group had determined that two materials were practical and sustainable options that
4
6. could be reused. However, the seat we had decided upon was less desirable than we had hoped
so we sought out a new option.
Construction of the Vehicle:
The construction phase of the bike required many methods in order to be successful. The group
had to create an agenda for every meeting so as to ensure efficiency and promote an atmosphere
of productivity. Every meeting the group would split into subsections of three members per
subsection to then accomplish the task given to them at that meeting. If a task proved
troublesome, and none of the members in the sub group could solve the issue within the task
deadline, the group would reconvene and determine the best solution by a decision matrix.
Success for the construction of the bike was justified by the production of an alpha prototype to
verify that our bike’s design was a viable option and then focusing on the adjustability of the
bike in the beta prototype.
Alpha Prototype Feedback:
Once we finished constructing our initial prototype, it included all the necessary functions to be
ridable however not all the desired final materials were used. This was done so that we could
easily change a few of the systems after getting feedback from our stakeholders and the public.
We sought out most of our feedback at the Madison Engineering Xchange, where our vehicle
was displayed to all passerbyes. During the event the team was approached by many Madison
engineering alumni and staff as well as some visitors. Several of the observers were very
encouraging and asked great questions about why we chose what we chose and why we put
specific parts in the places we did. It was challenging to answer some of the questions and lead
to a lot of self questioning on our part. All in all the feedback really encouraged us to look back
at our design and really think about improvements we could make for the beta prototype.
Results & Justification – Describe the results of design tool application
Pugh Chart
The pugh chart was used as our preliminary resource to assess the final designs provided from
each team member produced last year. We compiled this chart to narrow down the selection of
ideas, take the best features from each design, and move forward with a selected final design.
There were a total of eight proposed designs (including the datum), and five of those designs
showed to be promising. This design tool was based on a binary scale; meaning the rating for
each criteria was either better (+1), or worse (1), than the datum (0). The scores based off each
criteria (safety, ease of use, steering, etc) were added together for each design to receive an
overall score . Max and Jacob’s designs were similar and were used as the datum for the Pugh
chart, meaning all categories received a was neutral score of 0. Four designs chosen based off
their high score belonging to Nick, Evan, Tyler, and the team’s new iterated design incorporated
5
7. the top features from each of these designs. Nick’s design was selected since it received an
overall score of “+1” in the categories of weight, operation of vehicle, and cost compared to the
datum, but was worse than the datum in safety and aesthetics. Evan’s design was selected as it
received an overall score of “0” where it was perceived better than the datum in weight and
aesthetics, but was worse than the datum in steering and cost. Tyler’s design was selected as it
received an overall score of “+1” where it was perceived better than the datum in weight,
operation of vehicle, and cost, but was worse than the datum in steering and propulsion. The
team’s new iterated design received an overall score of “+3” where it was perceived better than
the datum’s propulsion, steering, operation, and aesthetics, but was worse compared to the datum
in the category of cost. These results were reached by an open discussion involving the whole
team allowing the team to come to a conclusion on the score received by each individual section
of criteria used.
Decision Matrix:
The top 5 designs from the pugh chart were then selected to be assessed in a decision matrix.
The same criteria the designs were graded on for the pugh chart was used for the decision
matrix, but for the decision matrix the criteria was weighted based on how it important it is to the
design. It is also a more detailed assessment of the designs as the ratings are on a 15 scale, 5
being the best and 1 being the worst. The weight of how much each criteria was worth was
determined by a group consensus of the team where the combined total of the weighted criteria
would need to equal 100%. Since our client was a young child that suffered from disabilities,
our biggest concern was the safety of the human powered vehicle and the ease of operation, so
we decided those would be the heaviest weighted categories at 15% each. The rest of the
categories that related to the subsystems of the design and the cost were all equally important and
we were weighted at 10%. The only category that was weighted at 5% was the aesthetics of the
human powered vehicle as this was seen as the least important aspect compared to the other
categories dealing with promoting independence and exercise for the rider. Then as a group our
team decided on each of the ratings for each section of criteria for each of the 5 designs based on
the background knowledge our team had on different types of bicycles that was translated into a
chart of metrics relating to each section of criteria. The newly iterated design by the team had
the best weighted score of 2.85. Max/Jacob’s and Nick’s design received a score of 2.65, Evan’s
design received a score of 2.60, and Tyler’s design received a 2.70. Our team’s newly iterated
design received a rating of 4 in steering, braking, safety, and aesthetics, but received a rating of 2
in cost.
Proof of Concepts and Back of the Envelope Calculations: (Figure 6 8)
Proof of concepts were made for each of the four subsystems: propulsion, steering/braking,
structure, and safety. The back of the envelope calculations were used as estimations for each of
6
8. the proof of concepts for the volume of each of the components then the mass was estimated by
using the known density of the material being used.
Design Decisions
After going through the design process for the past two semesters, our final design was based off
a standard recumbent delta. This design was chosen because of its stability and safety features.
The bike could also be built in a simplistic way that would allow for lightweight construction,
which is also why for the main frame we decided to only run one main tube to support the rider..
Another factor that brought us to the decision of a standard recumbent delta was that if the bike
was simply built, parts would be easy to source from local bike shops if anything were to ever
break, increasing the ease of maintenance. Along with the idea of ease of maintenance, we
wanted to incorporate an ease of use. Our final design included a twospeed automatic gear hub,
to allow the client to start the bike moving with ease, then allow him to gain speed when he
would be moving. Adjustability is also another factor when considering ease of use, so our final
design included an adjustable steering column, and adjustable seat, both vertically and
horizontally. An adjustable steering column would allow for the handlebars to be in the optimum
position, even when the seat would be adjusted. When the client is most comfortable, he’s the
safest because he will be at his maximum range of motion to be able to stabilize himself. The
adjustability of the steering caused a problem with input of the handlebars, which we solved with
a universal joint. The universal joint changes the direction of the steering input allowing the
column to be adjusted vertically without any issues. When it came to braking the idea remained
the same, simplicity is the goal. The bike had two brake handles suitable for a child’s hands, one
going to the rear axle where there was a disk brake style brake, and the other clamp style brake
going to the front wheel for emergency stopping. A big design hurdle was figuring out how to
minimize the main frame angle. We did this by choosing slightly larger rear wheels versus the
front wheels, these wheels were a balance of frame angle and keeping the right size wheels for
the client’s size and keeping in mind the terrain he was going to ride on. One of the last
decisions we had to make was how to attach our main frame to the rear tricycle axle, for this we
found an adapter that we were able to weld to the main frame so we were able to bolt straight to
the axle. This adapter also provided us with a spot to attach our gear hub for it to be an
intermediate between the rear axle and crank arm. There were many design decisions that the
team needed to make, as well as compromises to be able to get the bike done on time and within
specifications, we found that there was a happy medium between what was ideal and what
needed to be done.
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9. Reflection
Engineering is a meaningful profession, and I have learned that even students such as us can help
make a difference in this world. The idea behind being an engineer is solving problems and
helping those around us. It has been an amazing opportunity to be able to learn about engineering
through actually helping a kid in need. I was able to work alongside a real family and work with
my peers to design, build, and present a bike that I’m proud to call my own. I’m not sure many
engineering students can say that about their programs. I have learned a lot this semester,
including the importance of teamwork and leadership. Without guidelines for how the team itself
operates and someone to step up to guide the process, the team will fail, and any design or work
done will not be the best it can be. This class taught me to become that kind of leader and not
only to work alongside my peers but push them to be better as well as myself. This is how a real
team operates. There is always a goal, but if the individual and team do not improve and learn
along the way, then nothing has really been accomplished and the final product most likely is not
what it could be.
In designing a bike for Michael Bennett, an eight year old boy with Cerebral Palsy, I learned not
only what his disease is, but also what he can and can’t do and how that must have translated into
a bike design for him. This wasn’t a solution that could be used to help all others with
disabilities, but was special to Michael because my group and I talked to him, his family and
instructors personally. We observed him, measured him, and designed accordingly. Engineering
isn’t a field of study that is out to solve the world, but to carefully observe and design for
individual problems and present solutions that are efficient and sustainable, therefore making the
world a better and more comfortable place to live. I always knew I wanted to be apart of the
group who call themselves engineers and help solve problems, but never had a real taste of what
it was like until this class. It was truly an amazing opportunity to be able to design a bike for a
kid who only wants to be able to ride a bike with his brother. Personally, it made me think of
when I was younger and would ride around with my younger brothers. As an older brother, if a
group of college students helped build a bike for my younger brother, that would mean the world
to me, so to be able to be that college student is awesome. This class has only made me more
excited for what is in store, whether it be transitioning into a capstone project or when I graduate
and begin working in the real world as an engineer. I am enthusiastic that most all of the general
science and math classes are out of the way and although the engineering classes will get harder,
these classes are something I enjoy and a challenge I fully accept. I hope to make the best of my
time here at James Madison University because it is obvious that this new engineering program
we have is a special one and I want to take full advantage of anything and everything I can learn
and soak in. This project has been especially interesting to me since I enjoy medicine and would
like to pursue the field of Biomedical Engineering. I have no doubt that James Madison
University will prepare me for whatever job or graduate program lies ahead of me. Students
8
11. Accountability Report – Individual but signed off on by the team (see below)
Task Scott Max Jacob Joe Zach Steven Nick Tyle
r
Evan
Project Redesign Brief 11% 11% 11% 11% 11% 11% 11% 11% 11%
Formal Redesign
Presentation
11% 11% 11% 11% 11% 11% 11% 11% 11%
Proof of Concepts &
Back of the Envelope
Calculations Iteration 1
11% 11% 11% 11% 11% 11% 11% 11% 11%
Proof of Concepts &
Back of the Envelope
Calculations Iteration 2
14% 14% 14% 8.8% 8.8% 8.8% 14% 8.8% 8.8
%
Proof of Concept
Iteration 3
13% 13% 13% 9.6% 9.6% 13% 9.6% 9.6% 9.6
%
CAD Model for Human
Powered Vehicle
9.4% 25% 9.4% 9.4% 9.4% 9.4% 9.4% 9.4% 9.4
%
Bill of Materials & Cost
Estimation
14% 8.8% 14% 14% 14% 8.8% 8.8% 8.8% 8.8
%
Static Analysis (Center
of Mass)
9.6% 12% 9.6% 9.6% 14% 9.6% 9.6% 14% 12%
Static Analysis (Frame
Analysis)
11% 11% 11% 11% 11% 11% 11% 11% 11%
Understanding Impact 11% 11% 11% 11% 11% 11% 11% 11% 11%
Madison xChange Alpha
Prototypes & Poster
Presentations
13% 13% 13.8% 13% 9.6% 9.4% 9.4% 9.4% 9.4
%
Beta Prototype &
Podium Presentation
13% 10.2% 13% 10.2% 13% 10.2% 10.2
%
10.2
%
10.2
%
Prototype Testing Plan 11% 11% 11% 11% 11% 11% 11% 11% 11%
Design Portfolio 11% 11% 11% 11% 11% 11% 11% 11% 11%
10
14. References – ASME format
[1], Ralf Bohle GmbH, 2015, www.schwalbe.com,
http://www.schwalbe.com/en/reifenaufbau.html
[2], Lehigh County Pennsylvania, 2008, Rubber Recycling Facts,
https://www.lehighcounty.org/Departments/SolidWasteManagement/RecyclingFacts/Rubber/t
abid/524/Default.aspx
[3], Noel J Riggs and Steve B Scott, 2015, Top 5 Facts,
http://top5ofanything.com/list/7738a992/RubberProducingCountries
[4], User Name: Atom, 2008, The Rubber Tire Industry, http://rubbersb.blogspot.com
[5], Statista, 2014, Revenue of plastics & rubber machinery manufacturing (NAICS 33322) in
the United States from 2009 to 2014 (in billion U.S. dollars),
http://www.statista.com/statistics/291909/revenueofplasticsandrubbermachinerymanufact
uringintheus/
[6], Schwalbe North America, 2002, Company History,
http://www.schwalbetires.com/company/history
[7], Hugo Gye, 2013, Think your job stinks? Spare a thought for the sulphur miners of
Indonesia who scramble over a volcano in search of the valuable mineral,
http://www.dailymail.co.uk/news/article2336245/ThinkjobstinksSparethoughtsulphurmine
rsIndonesiascramblevolcanosearchvaluablemineral.html
[8], ConserveEnergyFuture, 2015, Rubber Recycling,
http://www.conserveenergyfuture.com/RecyclingRubber.php
[9], Jeff Salton, 2010, An effective, environmentallyfriendly way to break down old tires,
http://www.gizmag.com/scientistdevelopsmethodbreakdowntires/16907/
[10] “How Plastics Are Made.” How Plastics Are Made. N.p., n.d. Web. 30 Mar. 2015.
[11] Johnson, Todd. “Polyethylene Terephthalate”, About Composites. Web. 30 Mar. 2015.
http://composite.about.com/od/Plastics/a/PolyethyleneTerephthalate.htm
[12] Michelle Chong, Grace Kim, 2007. “The Recycling of Polyethylene Terephthalate”
COSMOS. Web. 30 Mar. 2015.
http://cosmos.ucdavis.edu/archives/2007/cluster8/chong_kim_ppt.pdf
13
15.
[13] TXOGA, 2013, Economic Impact, TXOGA, Austin
[14] Meyers, R. A., 2005. Handbook of Petrochemicals Production Processes
s.l.:McGrawHill.
[15] Johnson, T.,2015, What Is Polypropylene and What Is It Used For?
[16] Dym C.L.D, Little P.L.,Orwin EJO, 2014, Engineering Design, Edwards Brothers Malloy,
Ann Arbor
[17] Corbett GC, 2012, SOLIDWORKS 2012 Essential Training,
http://www.lynda.com/SOLIDWORKStutorials/SOLIDWORKS2012EssentialTraining/90422
2.html?org=jmu.edu
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