M202 Design Project

A – Cover Sheet P a g e | 1
MECH 202 – Spring 2015 Group 30 Project 2 – Lander Competition
A – Cover Sheet
Group Number: 30
Group Members Email Addresses
Keisling, Nate nate.keisling@gmail.com
Sandhu, Amroz Singh amroz@rams.colostate.edu
Sawyer, Chris cjsawyercsu@gmail.com
Visocky, Sean svisocky@rams.colostate.edu
Section Page
A - Cover Sheet 1
B - Title Page 2
C - Project Plan 3
D - Specification Development 10
E - Engineering Analysis 19
F - Concept Generation Concept Selection 39
G - Device Description 66
H - Bill of Materials 112
I - Testing 115
J - Reliability and Design Margin Analysis 119
K - Safety Analysis 127
L - Service and Support Plan 130
M -Teamwork Analysis 132
Supplemental Information Location
CERO files Included .ZIP file
Full QFD Excel worksheet Included .ZIP file
Full Final Gantt Table PDF Included .ZIP file
A

B - Title Page P a g e | 2
B - Title Page B

C - Project Plan P a g e | 3
C - Project Plan
Project Plan:
The project was managed using a Gantt chart. Tasks were created with a start date, end date, and task
owner. The percentage completion was then tracked against the actual date.
The project plan was drafted mostly at the first project meeting, and agreed upon by all members.
Weekly Snapshots of the Gantt Are Shown Below:
C

March 3 - This grid shows that Idea generation is 92% complete, but it was due three days before this
was taken. At this point we are starting to work on the device description, and prepare to manufacture
our first prototype.

April 6 - At this point, we had started manufacturing for our prototype, but we started falling behind
schedule especially with the sliding arm, and the engineering analysis of the winch, and start
mechanism. To fix this we sent out email reminders with specific tasks to accomplish and deadlines for
those tasks.

On April 11, we had fallen behind substantially in the device description, and testing. Our original Gantt
had us testing at this point, and we were not even done with the manufacturing.

On April 15, we had completed our manuf
acturing and had starting testing our device. At this point, we tried to take a dual approach with 2
members focusing on finishing the report, and 2 others to focus and nail down the testing and the
device improvements to make it functional.

Final Gantt chart Snapshots (A full PDF can be found in the included ZIP)

Summary:
Total Hours Spent: 165
Estimated Hours: 100
According to our project plan, we estimated that it would take us 100 hours to draft a project plan,
generate concepts, do engineering analysis of these concepts, and then manufacture a device. This is
65% over what we thought it would take. We were actually very close to our estimate areas in most
cases. The areas that took significantly more time than we thought, were idea generation, device
manufacturing and testing.
Task Name Estimate Hours Actual Hours % Deviation
Idea Generation 26 45 73%
Device Manufacturing 37 74 100%
Testing 10 18 80%
These tasks all took nearly twice as long as was expected, with manufacturing taking exactly twice as
long as expected.
Idea Generation- This took longer than expected because we did not consider how many steps and
different number of approaches we could take in the design. We ended up breaking down each function
in a morphological table and considering ideas of how to accomplish each task. Once we broke it down
to different components this went much faster.
Device Manufacturing- We did not consider all the redesign time when estimating this section. Several
items had to be redone, or even redesigned. This caused the time to increase much more than expected.
Testing- Again in this section we did not consider how many functions would not work, and then go back
find a new solution, and then test again.

D - Specification Development P a g e | 10
D - Specification Development
Note: Please take a look at the included Excell file. Our QFD is rather large!
D

Introduction
This section is quite directly the exact process laid out by Ullman Chapter 6. That being said, however,
there are some changes to note. First, we determined that we would modify the process slightly.
Because we were solving a new and unique problem, there is no competition to directly compare
ourselves to. We realized this would force us to either completely B.S. the entire Now Vs What section
up front or divert it and make use of it elsewhere. Our group decided the best choice would be to leave
out the Now Vs What and determine our specification targets based on our knowledge of the problem.
Then once we had developed and fleshed out our top concepts, the Now Vs What section and an
updated How Much section could serve as very useful metrics for our selection of our final concept. This
is reflected in the QFD at the end of this section, which has no Now Vs What section and a simplified
How Much section. While this may appear initially as an oversight, this is rounded out in Section F where
a complete QFD is one of the metrics used to compare our top concepts and select our final design.
Identifying Customers
We first addressed who our “customers” are. We could certainly pretend we’re developing a product for
production and sale but functionally in this very unique circumstance our customers can be very
effectively described as ourselves. We are designing and developing a device for the use in a competition
and as such, though the functional life of the product, it will interact with competitors and judges above
all else. In this sense we can consider “competitors” and “judges” the two primary target customers of
our device.

Determining Customer Requirements
But what do the customers want? We started with ourselves: What function do we require from our
device in order to compete?
 Must be allowed to compete
 Must function successfully in the competition
 Must be within the realm of what we can design and build
We expanded these broad categories slightly before evaluating their more specific components by
addressing the requirements laid out directly by the project file on pages one through four, including
some additions decided on by the team.
 Physical Requirements
o Meets dimensional requirements (18”x11”x3.5”)
o Meets weight requirement (less than 3 pounds)
 Administrative Requirements
o Does not affect other devices
o Stays within bounds
o Does not damage fixture
o Does not damage ball
 Functional Requirements
o Easy to set up
o Can be set up quickly
o Starts automatically
o Moves ball over wall
o Leaves ball in frame
o Returns to starting side
o Easily reset
o Completes objective quickly
o Is not affected by the environment or other devices
o Functions consistently and repeatedly
o Does not damage itself
 Manufacturing Requirements
o Easy to manufacture
o Easy to assemble
o Easy to maintain
o Easy to program
o Inexpensive

Then we considered the needs of the Competition Judges. These judges are far less concerned with the
function of the device and much more concerned with running the competition without any delays,
hazards, or technical violations. As such we determined the primary concerns of the judges were as
follows:
 Physical Requirements
o Meets dimensional requirements (18”x11”x3.5”)
o Meets weight requirement (less than 3 pounds)
 Safety Requirements
o Does not endanger onlookers
o Does not endanger other devices
o Stays within bounds
o Does not involve large enough forces to damage anything
 Balls, fixture, or itself
 Functional Requirements
o Set up does not delay competition
o Easily reset
o Is not susceptible to external influence
o Functions consistently as to provide peace of mind
o Does not damage itself
As should be very clear, there is a large amount of overlap between these two because the competition
requirements were laid out to include all of these very directly and deliberately. Some are concerns of
the competitors simply because they wish to be allowed to compete while some are concerns of the
judges simply because they want the competition to move smoothly and safely. These differences are
reflected next in the development of the fixed-sum Who Vs What metric on the QFD.

Who versus What
Our next step was to consider the importance of each requirement relative to each customer.
This was easiest regarding the judges, as they are clearly most concerned with the safety of themselves
and the contestants, the safety of the equipment, and the integrity of the competition, in approximately
that order. Some argument was had over whether or not competition integrity would fall before the
safety of the equipment, but it was decided that teams could always be disqualified and heats could
always be re-run, but you can’t un-damage the unique fixtures.
The debate over the distribution of the priorities of the contestants was more difficult. We started by
selecting our priorities. By a close margin and after significant debate, we decided that our device’s
ability to complete the functional objectives was more important than the device being allowed to
compete in the first place. While these are obviously the top two concerns, we made this distinction
because we wanted the QFD to prioritize the function of the device more heavily than it was going to if
we had focused on the device meeting the physical constraints. While we realize practically that not
allowing a device to compete makes its ability to function moot, we chose instead to break the fourth
wall, as it were, and make this decision based on increasing the effectiveness of the QFD.

Now versus What
To reiterate, given the unique circumstances of this competition, we do not have any competition to
compare until we’ve gone through the concept generation process and selected our top concepts. These
concepts will then be inserted into a complete QFD as a part of our Concept Selection process. To see
the full QFD, complete with the Now versus What section as well as a fully fleshed out How Much
section, please refer to Section F.

Specification Development
The development of our specifications was a slow evolution that grew in time with our understanding of
the problem and the potential solutions. Some things were obvious, like the constraints of the starting
area, the weight constraint, horizontal and vertical distances to be covered, and the time constraint.
Other things were not so easy gleamed directly from the Project Two file and the operational
requirements of the device. Our safety specifications came as a logically inductive expansion of what it
meant to fit the demanded safety expectations. Other specifications, like the “chance to fail”
specifications, came from evaluating the What section and filling in the blanks. This slow process
developed over 40 quantifiable specifications that we feel very deliberately and accurately break down
the problem.

How Much
The How Much section of the QFD was the most difficult. Because this is not only a unique problem, but
a problem with many potential solutions, it was challenging to nail down exactly what our specification
targets and thresholds were. Some thresholds were obvious- the device cannot weight more than 3
pounds and cannot have starting dimensions greater than 11x18x3.5 inches, for example. Others
required an extra leap of logic- the sum of the times require to go up, over, down, back up, and back
over must not be greater than 30 seconds, to state one case. The rest were determined by evaluating
how much force it takes to do certain things, like dent a ping pong ball or jostle a table. Any left overs
were left to the group- all four members gave what they thought were reasonable targets and
thresholds for each remaining specification and that information was averaged to give the information
found in the final QFD. We also considered that some of these may change drastically. As our design
analysis and concept selection continued, we revisited our specifications as seen fit, either by
developing tests or collecting more data from the group.
In order to compare our design to something relevant, we picked two designs that will most likely be in
the competition: catapult and quadcopter drone. These hypothetical competitors were compared to the
real data that we have from out device in order to draw our conclusions.

How vs How
This section was a monster simply because of the number of specifications. Fortunately, because our
specifications were detailed enough, there was an acceptably small amount of overlap and most of it
was in our favor (improving one spec improved others as well).

E - Engineering Analysis P a g e | 19
E - Engineering Analysis
Before we could begin any technical analysis of our problem, we needed to fully understand our
problem. To do this we very carefully read over the project document. The rules were straightforward,
but the dimensions of the fixture were of some issue. With the tolerances we had to work with we
needed to be very specific about how we went about our design. This meant measuring the fixture.
Figure E1: Our fixture measurements
E

After we had a firm understanding of the rules and fixture, we could start the analysis. To see a detailed
explanation of how we generated and selected our concepts to analyze, read on to the next section: “F -
Concept Generation and Selection.” Also, at the end of that section there are tables which summarize
the results and insights gained from our analysis.
The concepts, generated and selected in Section F, to be analyzed:
 Cover Horizontal Distance
o 2A – Scissor Lift
o 3A – Folding arm
o 3B – Sliding Arm
 Descend with the Ball
o 4A – Gravity Assisted Winch
o 4B – Folding Arm
 Release Ball
o 5A – Crane Game Hand
o 5B – Capsule
o 5C – Bucket
 Ascend
o 6A – Winch
o 6B – Tendons
 Power sources
o 8A – Batteries
o 8B – Stored Mechanical Energy
o 8D – Gravity
 Staying on the fixture
o 9A – Suction Cup
By far, the scissor lift mechanism was the most complicated concept to analyze. As such the most
time was spent on that process. We found a paper on the internet by H. M. Spackman, titled
“Mathematical Analysis of Scissor Lifts”, which helped greatly in this endeavor. The work presented
here is our own, but it was good to have a professionally validated sanity check!

Engineering Analysis – 1A – Electrical Contacts
Using electrical contacts touching the bar and completing a circuit to start the machine sounds nice on
the manufacturing end, but the technical end is more complex. Accounting for the bar’s resistance that
we cannot directly measure before the competition is nothing to bank on. This method should be
avoided.
Engineering Analysis – 1B – Spring Loading
Using this method would release our machine very quickly without some sort of limiting system. This is
not a great idea, as the time between when the bar is removed and replaced is both variable and
unknown to us when designing.
What then?
A similar idea to the electrical contacts would be a switch actuated by the pressure of the bar, not by
direct measurement of the bar’s resistance. How we didn’t realize this as an option when building our
Morphology is a mystery. Regardless, this method would be much more consistent, and how we should
build the first prototype.

Engineering Analysis – 2A – Scissor Lift

Now, for the important part! From the equations derived above, with our physical constants and our
hypothetical springs, we obtained these comparisons of the forces required to move the lift, Figure E2,
and the required strength of the winch holding the system down, figure E3. These figures will be
invaluable during the specific component shopping phase!
Figure E2: Horizontal Force Required vs Delivered (by the springs)
Figure E3: Resistive Vertical Force Required by a Winch (to hold the scissor down)

Engineering Analysis – 3A and 4A – Folding arm

Engineering Analysis – 3B – Sliding Arm

Engineering Analysis – 4A and 6A – Gravity Assisted Winch

Engineering Analysis – 5A – Crane Game
As you can see from this patent figure, a crane game claw would be rather complicated to make and
calibrate. For this reason, it would be a bad choice for this design.
Figure E2: The crane game claw, from Patent US6234487
Engineering Analysis – 5B – Capsule
A capsule involves a cradle around the ball which is mechanically opened after being lowered or fired. It
would be more complicated than a bucket.
Engineering Analysis – 5C – Bucket
A bucket is a capsule with no moving parts or door, but only an opening. We’ve come up with a novel
design which holds the ball in while being lowered, then tips over, releasing the ball, on contact with the
ground. It is covered in greater detail in “Section G - Device Description”.

Engineering Analysis – 6B – Tendons

Engineering Analysis – 8A – Batteries
There are many types of batteries to compare, but it is common knowledge that Lithium Ion based
systems have the best power/weight/voltage output ratios. For our application, since we are only
powering an Arduino microcontroller and possibly only one servo motor, we don’t need high capacity.
This is the lithium technology’s only downside, so this is the best choice.
http://www.watchbatteries-usa.com/faq.html
Figure E3: Volage/Capacity Discharge graphs for several battery types

Engineering Analysis – 8B – Stored Mechanical Energy
Our designs will most likely incorporate springs of some type. Mostly the standard tension type, but
some constant force springs could prove useful. The scissor lift analysis went into detail about where we
would be using them.
http://www.constantforceusa.com/media/images/Products_SpringsandVersa-TrakMain.jpg
Figure E4: Constant force springs
Engineering Analysis – 8D – Gravity
When it is possible, one should use gravity to their advantage. It’s hard to fight and easy to harness. (At
least in one direction!) Whichever ball holding device we chose, it will most likely use gravity to power
the descent. That’s one less component to power and one less mechanism to design.

Engineering Analysis – 9A – Suction Cups
A mechanical suction cup will help our device stay centered where we place it on the fixture. It is easy to
attach to the device base and, other than adding weight, there are little downsides and we should
include it in the design.
http://www.designworldonline.com/keys-to-applying-vacuum-systems/
Figure E5: from Design World, the force diagram for a mechanical suction cup
Conclusion:
While all these equations and figures may seem overkill considering the scope of our problem, they’ve
given us invaluable insight into our potential design concepts. For that they were worth the time put
into the process, and hopefully will result in a better device.

F - Concept Generation and Selection P a g e | 39
F - Concept Generation and Selection
A Note:
While this section isn’t particularly important in the context of our report grade, we wanted to come out
of this experience having produced the best device we possibly could have. To that end, we have
dwelled disproportionally long on this section and its contents and paid special attention to the details.
We have done this because to produce our best, we wanted to front-load our thinking and solve
problems before we encountered them. Thoroughly working out the details before we’re committed to
anything is the best way to ensure that we’re not going to need to restart in the middle of the project
and are simply on the correct path to begin with.
F

Concept Generation:
The process that we’ve implemented to generate then aid in the selection our final design concept is
described in detail by “Building a Morphology”, from Ullman’s Mechanical Design Process, Fourth
Edition, Chapter 7.8. To quickly describe the process, it can be dissolved into three main steps:
1. Decompose the Function
2. Develop Concepts for Each Function
3. Combine Concepts
Step one is straightforward in name. The overarching function of the device is separated into sub
functions which are described very abstractly. This allows significant engineering freedom in step two.
This second step involves coming up with several abstract ideas which could fulfill the functions
described in step one. Abstract in this case means “how”, not “what”. We’re not describing mechanisms,
but ideas which may be translated to one or more actual mechanisms. The benefit of this process is
apparent after completion, where one sees that by not in any way committing to one concept early on
many more concepts can be fairly considered. In this way the best method can be found out then
translated into a physical mechanism to actually achieve the stated purpose.
Step three involves constructing a morphological table, whose rows are populated with potential
concepts which are solutions to the sub functions. The sub-functions are the row headers. After the
table is made, then one can go down the columns, selecting one concept from each row, to assemble a
set of concepts which could be easily engineered into a functional machine which fulfills the started
goal. Not all of the combinations result in a cohesive or even possible set, but this method allows for the
generation and selection of many ideas without leaving anything out. The potential combinations are
compared later to end up with the one best idea. In our case, this will be done with a concept selection
matrix.

Morphology Step 1: Decompose the Function
In the case of this project, we didn’t need to put significant thought into the decomposition of the
function of our device because the instructors (partially) did so for us! The following screenshot is from
Project2-Rev2.pdf
[Figure F1: The decomposed function]
From this list, we devised a more complete list of linearly related tasks for the device to complete:
1. Start Autonomously
2. Cover the Vertical Distance
3. Cover the Horizontal Distance
4. Descend with the ball
5. Release Ball
6. Ascend
7. Return to Starting side
8. Define a power source
9. Method of staying on the competition fixture
Steps 8 and 9 are not strictly part of the linear task process, but are important to consider in this phase
of the design. The tasks in figure F1 not mentioned here are not relevant to the active function, but will
be addressed later.

Morphology Step 2: Develop Concepts for Each Function
In order to create the best functioning device that we could, our group generated many, many concepts.
To that end we utilized several methods for concept generation as presented in class. They are
highlighted in blue in Figure F2.
[Figure F2: Methods For Generating Concepts, from class lecture 9]
First, we used a several hour meeting of all four group members as a mass Brainstorming session. The
results of that meeting are reproduced below. In the middle of this session, we consulted a very
reputable outside source for potential input to our problem. We then used the internet as a reference
to quickly validate the ideas we generated there as potential concepts, and in the process picked up a
few new ones. Finally, and while Incorporating the basis of Axiomatic Design, we produced a large
Morphological Table to aid in the concept selection process.

Morphology Step 2: Develop Concepts for Each Function – Brainstorming
This is a cleaned up version of the flowchart that resulted from our group brainstorming session
[Figure F3: Our Brain Storming Flow-Chart, made with www.draw.io]

Morphology Step 2: Develop Concepts for Each Function – Outside Source
In the middle of our Brainstorming meeting, a small, secondary
flowchart was included next to the primary one. It encapsulated a very
good idea. That idea was to seek outside help with our design process.
Who is possibly the single best regarded engineering firm? NASA. The
National Aeronautics and Space Administration. A clear choice.
Contact was made immediately!
[Figure F5: The Message to NASA]
Unfortunately, at the time of writing we have received no response 
[Figure F4: Our Great Idea]

Morphology Step 2: Develop Concepts for Each Function – External References
At this point, presenting our exact thought progression is a bit complicated. A bit of research resulted in
a several images found on the internet which provided inspiration and a few good websites containing
handy equations. A selection of the images are presented here and the equations can be found in the
Engineering Analysis section, along with many we’ve derived ourselves!
http://www.northerntool.com/images/product/2000x2000/430/43007_2000x2000.jpg
[Figure F6: A vertical Scissor Lift]
http://www.aliexpress.com/item/Free-Shipping-Stroke-50mm-2-inches-24V-600N-60KG-mini-electric-
linear-actuator-linear-tubular/32252064724.html
[Figure F7: a Linear Actuator]

http://www.forbes.com/sites/markrogowsky/2013/12/03/that-buzz-you-hear-isnt-an-amazon-drone/
[Figure F8: Amazon’s Quadcopter]
http://abcnews.go.com/Technology/amazon-prime-air-delivery-drones-arrive-early-
2015/story?id=21064960
[Figure F9: Amazon’s Quadcopter, a different view]

http://www.joystixamusements.com/photos/TOY%20SOLDIER%20JUMBO%20CRANE.JPG
[Figure F10: A Toy Crane Game]
[Figure F11: The crane game claw, from Patent US6234487]

https://c2.staticflickr.com/2/1045/1087840678_4ff1dbe3b6_b.jpg
[Figure F12: Ping-Pong-Ball cannon]
http://www.robotsnob.com/pictures/turbinebot.jpg
[Figure F13: a magnetic wind turbine climbing robot]

We found a great paper published by the US Marine Corps written by a H. M. Spackman, titled
“Mathematical Analysis of Scissor Lifts”, which was about the mathematics behind scissor lifts. The
details gleamed from this were invaluable for our analysis. The math is incorporated in the above
section, Engineering Analysis. Figure F14 represents a few of the more visually interesting sections:
[Figure F14: Visually Interesting Sections from the Paper]

Morphology Step 2: Develop Concepts for Each Function – Axiomatic Design
First off, what exactly is Axiomatic Design?
From Wikipedia:
[Figure F15: Axiomatic design, as described by http://en.wikipedia.org/wiki/Axiomatic_design]
Now what exactly does this mean? In short, the two axioms can be summarized: A good design keeps
the internal processes as abstract as possible, then after fully understanding the available conceptual
options the actual physical designs are made. In this way the best design or designs can be found
without being caught up on the details of implementation too early on. This requires a high level of
engineering knowledge and a complete understanding of the problem to be solved, but it consistently
produces a good final product.
The actual details of this approach can be very complicated, but there are tools to help keep track of the
ideas used by the methodology. One of these tools is the Morphological Table, which we have been
preparing to make and will finally will use over the next several pages to help explain our process.
Axiomatic design is a systems design methodology using matrix methods to systematically
analyze the transformation of customer needs into functional requirements, design parameters,
and process variables.[1]
Specifically, functional requirements (FRs) are related to design
parameters (DPs):
The method gets its name from its use of design principles or design Axioms (i.e., given
without proof) governing the analysis and decision making process in developing high quality
product or system designs. The two axioms used in Axiomatic Design (AD) are:
 Axiom 1: The Independence Axiom. Maintain the independence of the functional
requirements (FRs).
 Axiom 2: The Information Axiom. Minimize the information content of the design.

Morphology Step 2: Develop Concepts for Each Function – Morphological Table
Over the proceeding pages, we have stepped through the process by which we have generated our
design concepts. These are not specific designs, but ideas which describe a process that a specific design
would later be created to accomplish. Of the three steps in building a morphology, we have done steps
one “Decompose the Function”, and two “Develop Concepts for Each Function.” We have only Step
three, “Combine Concepts” yet to do. To combine our concepts, we needed to finally assemble a table
from the list of concepts that we had just generated. That process resulted in the following figure:
[Figure F16: Our Morphological Table]

Morphology Step 3: Combine Concepts
Before combining our finalized concepts from step two, we need to first prune them with a process
known as “Feasibility Evaluation.” This process is described in section 8.3 of Ullman’s Mechanical Design
Process, Fourth Edition. It has us categorize the generated concepts into three categories.
1. It is not feasible
2. It is conditional
3. It is worth considering
The only of these categories not obvious in function is the second, “it is conditional.” This means that it
is possible for this design to work, but it hinges entirely on currently unknown or unobtainable
information. This category is for ideas not outrightly incorrect, but that require either chance or
incalculable parameters be met, and are therefore unreliable.
The following pages reflect this pruning process.

Morphology Step 3: Combine Concepts - Feasibility Evaluation - “It is not feasible”

Morphology Step 3: Combine Concepts - Feasibility Evaluation - “It is not feasible”
Start Autonomously
Item Removed Cell Reason
Visual Sensor 1D Unreliable without significant calibration, something we cannot do
Cover the Vertical Distance
Jumping Spring 2B The spring force required to launch the 3lb mass is too high
Climbs 2E The hanging wire structure will not provide enough rigidity to climb
Inflated Shape 1 2F Fixture geometry does not allow this design to function as the height of
the fixture is significantly larger than the width we need to traverse, so
no continuously expanding tube geometry could work
Cover the Horizontal Distance
Flop 3E There is too much variability to coordinate this maneuver safely
Inflated Shape 2 3F See “Inflated Shape 1”
Descend with the ball
Fall 4E Falling may damage our machine or the fixture
Inflated Shape 3 4F See “Inflated Shape 1”
Ascend
Delates and Retracts 6F See “Inflated Shape 1”, also the tubing would be damaged getting pulled
over the wires so it would only function once. Non ideal.
Climbs Back 6E Re-finding the wire structure to climb would be too complicated
Return to Starting side
Flop Again 7E This may damage the fixture and device
Continue Retracting 7F See “Delates and Retracts”
Define a power source
Compressed Gas 8C This may be dangerous with the scale of pressure needed to be effective
Method of staying on the competition fixture
Weight Alone 9B This is entirely unreliable on a smooth surface like the fixture
Magnets 9D The fixture is not magnetic
Hooks 9E This will damage the fixture

Morphology Step 3: Combine Concepts - Feasibility Evaluation - “It is conditional”

Morphology Step 3: Combine Concepts - Feasibility Evaluation - “It is conditional”
Start Autonomously
Magnetic Release 1C This mechanism would be prone to early triggering without calibration
Cover Vertical Distance
Quadcopter 1 2C Without extremely significant testing and calibration, this method would
not be able to reliably function, if at all. This lack of testing time could
even prove dangerous to onlookers or the fixture, which needs to be
absolutely avoided.
Launch It 1 2D This method would need calibration with a specific ball and lane,
something our group cannot attain before the first competition round
Cover Horizontal Distance
Quadcopter 2 3C See “Quadcopter 1”
Launch It 2 3D See “Launch It 1”
Descends with Ball
Ball Descends Alone 4D See “Launch It 1”
Releases Ball
Decaying Bounce 5D See “Launch It 1”
Sphincter 5E Air pressure on the tube would need to be calibrated much too precisely
Ascends
Returns to Starting Side
Stay on the Fixture
Expanding Clamp 9C To center in the fixture we would need to know the exact width of our
lane, something we can’t measure until the first completion round

Morphology Step 3: Combine Concepts - Feasibility Evaluation - “It is worth considering”

Morphology Step 3: Combine Concepts - Feasibility Evaluation - “It is worth considering”
The Remaining items on the Morphological table have been deemed to be worth considering for
possible incorporation into our design. To this end, we needed to entirely understand them from a
numerical, engineering-based standpoint. The full extent of this detailed analysis is the focus of the
preceding report section, “Section E – Engineering Analysis.” The results are summarized on the next
section, “Concept Selection”.
Items Worth Considering:
 1A – Electrical Contacts
 1B – Spring Loading
 2A – Scissor Lift
 3A – Folding arm
 3B – Sliding Arm
 4A – Gravity Assisted Winch
 4B – Folding Arm
 5A – Crane Game
 5B – Capsule
 5C – Bucket
 6A – Winch
 6B – Tendons
 6D – Device Never Descends
 7A – Refold
 7B – Un-slide (3B backwards)
 7D – Device Never Crosses Wall
 8A – Batteries
 8B – Stored Mechanical Energy
 8D – Gravity
 9A – Suction Cups

Concept Selection:
Baseline
ElectricalContacts
orPhysicalSwitch
SpringLoaded
MagneticRelease
VisualSensor
(1) Autonomous Starting Weights
Detects starting bar 25
Datum
1 1 1 0
Allows for variability 15 0 1 1 -1
Reliable 10 0 1 -1 -1
Will not damage itself 10 1 0 1 1
Easy to set up 10 1 0 -1 -1
Compact 15 1 -1 0 1
Lightweight 15 1 -1 0 1
Total 5 1 1 0
Weighted Total 75 20 30 5
For the process of autonomously starting the device, the key issue was what would detect the starting
bar, do so despite variability in placement and differences in the lane, and remain low impact on our
weight and size constraints. It was also worth considering whether or not the design involved forces that
might damage itself or the device as well as whether or not the design was easy to set up.
The electrical contacts/switch concept clearly performed the best. Our team voiced concerns that a
small electrical switch require an advanced mounting solution to allow for variability in the fixture and
not inadvertently be triggered or released early or in the middle of operation. This was solved by
deciding to have a switch that received the bar upon placement in the secondary position as opposed to
being triggered by the removal of the bar from the starting position as well as programming the device
to start and continue with its programming whether or not the state of the switch changed after initial
triggering.

Baseline
ScissorLift
Copter
LaunchIt!
Climbthewall
(2) Covering the Vertical
Distance
Weights
Can easily cover >24” 15
Datum
1 1 1 0
Requires minimal energy 10 0 1 1 0
Simple 10 1 -1 1 0
Fast 15 1 1 1 -1
Reliable 9 1 0 -1 0
Safe 8 1 -1 0 1
Easy to set up 8 1 1 0 1
Compact 15 1 1 1 1
Lightweight 15 0 1 1 0
Total 7 4 5 2
For moving the ball upward in preparation to move it then over and back down (the simplest description
of the general solution to the problem) our top for concepts were the Scissor Lift, a quad-copter drone,
simply launching the ball, and climbing the wall with magnetic treads or hooks. We ruled out an inflated
shape and a “jumping” device based on force constraints and the inconsistency of the concepts on an
inherent level.
The criteria were decided on knowing that above anything else, this would be the most complicated part
of the device and would need to, at a base level, cover the vertical distance, do so quickly, meet the
dimensional constraints, and do this process simply and without requiring an excess of energy or force.
We also considered the reliability, safety, and ease of set up. It was in this order we decided on the
importance so they were weighted accordingly.
While the scissor lift received the best score and received no “-1” ratings, the Copter and launching the
ball were close enough to consider in more depth. It was determined, as reflected in the Morphological
Table, that there were too many things that would have to fall in line for the copter and launching
solutions to function given our financial, time, and expertise constraints. The copter was too
technologically advanced to develop from scratch in a way where we could guarantee safety and
consistency and was considered to be too expensive to simply buy and modify. The launching solution
was determined to be clever and the most simple solution, but had too much variability and after briefly
testing several different brands of ping pong balls, we decided there was too much variability in weight
and bouncing behavior to develop this solution consistently enough. The scissor lift was determined as
our only viable option given the constraints and in depth analysis was started immediately.

Baseline
FoldingArm
SlidingArm
HorizontalScissor
Launch/dropit
(3) Horizontal
Displacement
Weights
Covers >4.5” 25
Datum
1 1 1 1
Starts at the right time 15 1 1 1 0
Reliable 10 1 1 1 -1
Fast 10 0 0 1 1
Easily Retractable 10 0 1 1 1
Smooth 10 -1 1 1 0
Compact 10 1 1 -1 -1
Lightweight 10 0 1 0 0
Total 3 7 5 1
At this point it is important to note that we’ve deviated from the morphological table. This trend will
continue. Because the processes of this device have to happen in sequence and each process has to be
compatible with the processes before and after it, if we determined a clear winner in a previous Concept
Selection Matrix, this will change the designs considered after that point.
For example, much discussion occurred over the previous concept selection matrix which lead to
significant research and even some testing. The delay between the writing of the previous matrix and
this one was about two days. Only after finalizing the decision to use a scissor lift did we continue
developing these matrices. Since we knew that that certain designs had been considered infeasible, it
was not worth further considering their “daughter” designs- parts of those designs that would function
later down the line. As such, we went to comparing designs that could feasibly be attached to the top of
a scissor lift, leaving out unrelated concepts from the morphological table and even introducing some
new designs we hadn’t previously considered, like a horizontal scissor lift.
These concepts were compared on a series of datum, the most important of which were determined to
be covering the horizontal distance and not starting too early, which could jam the device and damage
the fixture. It was also considered whether each concept would be reliable, fast, retractable, smooth,
compact, and lightweight. We decided these held roughly the same weight.
The sliding arm and the horizontal scissor were the top two designs. The folding arm was left out
because it did not leave very many options for a ball-holding solution. Those decisions are reflected in
more detail in the engineering analysis section.

Baseline
GravityAssisted
Winch
BallisDropped
(4) Descent Weights
Precise 25
Datum
1 -1
Starts at the right time 15 1 0
Reliable 15 1 -1
Fast 10 0 1
Easily Retractable 15 1 1
Smooth 10 1 0
Compact 10 0 1
Total 5 1
Weighted Total 80 -5
To continue the previous discussion, you can see clearly that the concepts for the actual function of the
device have converged slightly. It has been decided that something will be extending out over the target
and the ball will be allowed to cover the descent from there. This leaves a very narrow range of possible
concepts- either it can be lowered or it can be dropped.
These two ideas were compared on, most importantly, their precision, not starting too early, general
reliability, and the ability for this to be retracted later on. We also considered the speed of the solution,
as well as the smoothness and compactness of the solution.
Actually lowering the ball is the clear winner here. The nature of that process, as this time, had yet to be
determined but was decided on during the engineering analysis portion, which occurred semi-
concurrently with this process.
Important Note: Because this now converges to a single solution, there is no need for concept
selection for ascending and returning to the starting side. These processes will happen via a winch of
some form pulling them back in. The concept selection focus from this point will be the finer details of
the mechanism and will diverge almost completely from the Morphological Table.

Baseline
SpringLoaded
Claw
SpringLoaded
Capsule
Sphincter
OccamsBucket
Holding the Ball Weights
Will not drop the ball 20
Datum
0 1 0 1
Mechanically simple 15 -1 0 1 1
Can spin 10 1 1 0 -1
Fast 10 1 1 0 1
Reliable 15 0 1 1 1
Easy to build 5 -1 0 1 1
Compact 10 1 -1 0 1
Accepts variability in balls 15 1 1 -1 1
Total 2 4 2 6
This section is debating what exactly will be on the end of the winch to hold the ball while it’s lowered
and then release the ball in contact with the ground. It was clear that building electronics into this was
infeasible so it has to function mechanically. Our initial designs were a spring loaded claw, a spring
loaded capsule, and a pressure loaded sphincter. We were dismayed at the complexity of each of these
systems before Nate came up with the idea of a box that’s base was tilted and center of gravity offset
such that when it touched the ground it simply tipped over and the ball rolled out. Considering the
simplicity of this solution we dubbed it “Occam’s Bucket” as an homage to Occam’s Razor, the
philosophical version of “Keep It Simple, Stupid.”
The most important criteria for these ball holders was that it did not drop the ball prematurely, is
mechanically simple and reliable, and will accept balls of many sizes and weights. It was also considered
that it should be fast, compact, and easy to build. We also determined that we were going to be
dropping the ball close to the edge of the target, so the chosen design should also not spin and release
the ball in the wrong direction.
The clear winner here was Occam’s Bucket, especially after deciding that the winch could be wired with
flat ribbon, discouraging the tipping bucket to spin off target.

Baseline
Drivenbycommon
mechanical
process
Eachprocessis
drivenseparately
ScissorandArm
arelinked
ArmandDescent
arelinked
Stages of Operation Weights
Intercompatible 25
Datum
1 -1 0 1
Intracompatible 15 1 1 0 1
Reliable 15 0 1 1 1
Fast 10 1 -1 0 1
Easily reversed 5 0 1 -1 1
Low energy demand 5 -1 0 1 1
Easily developed 15 1 -1 -1 0
Lightweight 10 1 -1 -1 -1
Total 4 -1 -1 5
Weighted Total 70 -35 -10 60
Next we needed to decide how to run each subsystem (up-over-down-up-back) in order consistently. It
was most important that the process used drive the systems be compatible between each system
(intercompatible) as well as each process driving the system be compatible within each system
(intracompatible). The next most important values are the system’s reliability and it’s ease of
development, which includes programming, machining, and assembly. On top of that we also
considered the speed of the system and how lightweight it would be, as well as the energy demand of
the system and how easily it could adapt to the final steps (-up-back), which are the most functionally
divergent.
It was determined that driving the systems with a common winch that doled out to allow the scissor to
expand and then the arm and then drop the bucket before reversing and pulling it all back in would be
most effective based on the weighted total. However, having a single mechanism handle the scissor and
a second mechanism let out the arm and drop the bucket would be almost equally as functional, losing
out only in weight and the complexity of development.
Our concerns with the latter system were the size and weight constraints of fitting electronics on the top
of the scissor lift and the complexity involved in programming and testing the system. It also
approximately doubled our projected costs on electronics, which was already our highest expected
expenditure. For these reasons we opted for the slightly less reliable but notably simpler design of a
single continuous winch.

G - Device Description P a g e | 66
G - Device Description
Any device needs a name. It can be boring, descriptive even. A great device? That needs an identity. A
device showing once-in-a-lifetime innovation and spirit? That needs a logo. One worthy of equal praise.
We believe that we have achieved this lofty goal.
Figure G1: The Device’s Logo
Why? Because absolutely no one else at this competition will have a scissor lift, and pirates are fun!
Anyway – this is a long section. As such, a summary to guide you through its reading is necessary.
The sub-sections herein:
 Engineering drawings of all parts
 3D models of the most critical parts of the device
o The models are to scale, and the CREO files are inside of our included ZIP file
 Process sheets for manufacturing all parts
 A summary of the assembly process
 The steps of the process by which our device operates
o A summary of our electronic systems
 The critical design elements for the working of our device
 Some cleaver ideas that make our device unique
G

Engineering Drawings

Engineering Drawings: Sliding Arm Cover/Sliding Arm

3D models of the most critical parts of the device: Sliding Arm Closed/Sliding Arm Open
Note: there is a ‘key reel” hooked into the slot on the back of the cover, fed through the channel in the
cover and attached to the back of the arm, this is the spring which powers the opening of the arm.

3D models of the most critical parts of the device: The Base

Part Name: Top Base
Quantity: 1
Material: ¼” thick birch ply
Weight: 0.45 pounds (estimated)
Supplies and Tooling:
 Table Saw and Band Saw
 Drill Press with 1/8” and 1/4" bits
 Dremel tool with slot cutter if available
Notes: All dimensions tolerance to ±0.01” unless otherwise stated. The drawing is the best
reference for dimensions.
# Process
1 Set table saw guide to cut 18”.
2 Make 18” cut on birch ply.
3 Set table saw guide to cut 8.5”.
4 Make 8.5” cut so that you are left with an 18x8.5” rectangle.
!!! Now would be a good time to trim the remaining 18” swath of stock into the 18x11” Bottom Base.
Please see the Bottom Base process sheet for more information.
5 Carefully mark 5x4” rectangle at top of piece, 1.75” from each corner, such that the 5” dimension lies
in the direction of the 8.5” side, as per given drawing.
6 Carefully mark 5x10” rectangle 1.75” from each bottom corner such that the 10” dimension lies in the
direction of the 18” side, as per given drawing.
7 Carefully mark 1.5x2” rectangle 6” from the top right corner, along the right side, such that the 2”
dimension lies in the direction of the 18” side, as per given drawing.
8 Transfer piece to band saw running skip tooth blade at recommended speed stated on saw.
9 Carefully cut the left 10” dimension of the bottom rectangle. After meeting length requirement guide
material backwards a few inches before turning off the saw. Once the saw has stopped, guide blade
out of cut.
10 Carefully cut the right 10” dimension. About 4” from end, begin to gently twist piece to guide blade
inward, cutting a curve that tapers off tangential to 5” dimension, as per given cut suggestion on
drawing. Carry this cut through to the previous cut in corner of rectangle. Stop blade and remove
loose material (should be majority of 5x10” rectangle).
11 Spin the piece around and make two final cuts to remove the leftover corner, shown cross-hatched
on given drawing.
12 Carefully cut the right 4” dimension of the top rectangle. After meeting length requirement guide
material backwards a few inches before turning off the saw. Once the saw has stopped, guide blade
out of cut.

13 Carefully cut the left 4” dimension. After about a half inch, begin to gently twist piece to guide blade
drawing. Carry this cut through to the previous cut in corner of rectangle. Stop blade and remove
loose material (should be majority of 5x4” rectangle).
on given drawing.
15 Carefully cut the bottom 1.5” dimension of the smallest rectangle. After meeting length requirement
guide material backwards a few inches before turning off the saw. Once the saw has stopped, guide
blade out of cut.
16 Carefully cut the top 1.5” dimension. Immediately twist piece to guide blade downwards, cutting a
curve that tapers off tangential to 2” dimension, as per given cut suggestion on drawing. Carry this
cut through to the previous cut in corner of rectangle. Stop blade and remove loose material (should
be majority of 2x1.5” rectangle).
on given drawing. Consider breaking this up into smaller triangles if necessary. It is ESPECIALLY
important not to over cut in the 2” direction given the locations of the 1/8” holes for attaching
constant force springs.
18 Measure out and mark the location and shape of the 0.5x0.25” thru slot as per given drawing.
!!! The key dimensions for this cut are location and perpendicularity. ESPECIALLY perpendicularity. If it
wasn’t clear from the assembly drawings, this slot is for an L bracket that guides the main cable down
towards the bottom base. If all else fails, cut extra space so the bracket can be glued into place at a
proper angle.
19 Place the piece on the small drill press (with 1/4” bit) and clamp it in place.
20 Drill 1/4” thru holes on each end of the rectangle you marked for the slot.
21 Exchange bit for 1/8” bit.
22 Drill the two holes near the smallest rectangle. The critical dimension for these is 0.25”.
23 Acquire Dremel Tool. If a 0.125” notch cutter or cylindrical sanding bit is available, use that. If not, get
a fine point sander and be careful.
24 Prop the piece up on scrap wood so that there’s at least 0.25” of space between the piece and the
table.
25 Slowly and deliberately grind into the piece to complete the slot.
26 Weigh the piece. If it weighs more than 0.75 pounds, call Nate immediately (719) 648-2291
Also, cry. Probably crying is good. Especially if it weighs more than 1 pound.
Because then we’re straight f****d. <3

Part Name: Bottom Base
Quantity: 1
Material: ¼” thick Birch Ply
Weight: 0.55 pounds (estimated)
 Table Saw and Band Saw
 Drill Press and 1/8” bit
 Dremel Set with slot cutter if available
# Process
2 Make 18” cut on birch ply.
4 Make 11” cut so that you are left with an 18x11” rectangle.
!!! Now would be a good time to trim the remaining 18” swath of stock into the 18x8.5” Top Base.
Please see the Top Base process sheet for more information.
5 Carefully mark 2.5x8” rectangle in bottom left corner of piece, such that 8” dimension lies in the
6 Carefully mark 5x10” rectangle 1.75” from bottom right corner such that the 10” dimension lies in the
7 Transfer piece to band saw running skip tooth blade at recommended speed stated on saw.
8 Carefully cut out rectangle in bottom left corner by making two perpendicular cuts along drawn lines.
9 Carefully cut the left 10” dimension. After meeting length requirement guide material backwards a
few inches before turning off the saw. Once the saw has stopped, guide blade out of cut.
10 Carefully cut the right 10” dimension. About 4” from end, begin to gently twist piece to guide blade
drawing. Carry this cut through to the previous cut. Stop blade and remove loose material (should be
majority of 5x10” rectangle).
11 Spin the piece around and make two final cuts to remove the left over corner, shown cross-hatched
on given drawing.
!!! Now might be a good time to make cuts to finalize the cuts for the Top Base.
Please see the Top Base process sheet for more information.
12 Don’t be a dick- clean the table saw and band saw before moving on. Keegan puts up with enough.
13 Measure out and mark the location and shape of the 0.5x0.125” thru slot as per given drawing.

!!! At this time, do NOT mark the 0.5x0.75” pocket. Just trust me on that. Method to my madness.
!!! The key dimensions for this cut are location and perpendicularity. ESPECIALLY perpendicularity. If it
wasn’t clear from the assembly drawings, this slot and pocket are for an L bracket with a slot milled
into it that serves as a pulley for the main cable. If all else fails, cut extra space so the bracket can be
glued into place at a proper angle.
14 Place the piece on the small drill press (with 1/8” bit) and clamp it in place.
15 Drill 1/8” thru holes on each end of the rectangle you marked for the slot. If you’ve got balls go ahed
and do a third in the center; it’ll save time later, but it may be difficult to make that cut without
deflection. You do you. I believe in you.
16 Acquire Dremel Tool. If a 0.125” notch cutter or cylindrical sanding bit is available, use that. If not, get
a fine point sander and be careful.
17 Prop the piece up on scrap wood so that there’s at least 0.25” of space between the piece and the
table.
18 Slowly and deliberately grind into the piece to complete the slot.
19 Orient piece as shown in drawing.
20 Mentally (or physically) mark the side of the piece facing you as the TOP.
21 Now flip the piece over. This is the BOTTOM.
22 Upside down like this the piece should look all backwards and flip flopped from the drawing.
23 That’s because you’re looking at the BOTTOM. This is good.
24 BOTTOM GOOD. TOP BAD.
25 On the BOTTOM of the piece, mark the dimensions of the 1/16” deep pocket.
26 Using the appropriate Dremel attachment, mill the pocket on the BOTTOM of the piece.
27 If available, test the slot and pocket for fit with the milled L bracket piece.
28 Weigh the piece. If it weighs more than 1 pound, call Nate immediately (719) 648-2291
Also, cry. Probably crying is good. Especially if it weighs more than 1.5 pounds.
Because then we’re straight f****d. <3

Part Name: Lift Member
Quantity: 8 Required. Make 12-16.
Material: 21” Paint Stir Sticks (1/4” thick)
Weight: 0.05 pounds each (estimated)
 Band Saw
 Pick your favorite wood-friendly sander
 Milling Machine – Jacobs Chuck, edge-finder, and 3/16” Two Fluted End Mill in 3/8”
collet
 Special mounting hardware
 A friend
# Process
1 Begin by carefully drawing the outline of the member on the clean side of the paint stick. One side of
the member should align with one side of the pain stick. Consider using a ½” diameter rod of some kind
to trace the curves on the end. It’s not ideal to freehand those.
!!! It is possible to produce two members from one paint stick, but these paint sticks are free. If you feel
it’s faster or more accurate one way or the other, do that.
2 Load a rake tooth blade in the band saw and make sure the speed is set to about 1500 fpm (rpm?)
!!! Yes, rake tooth. It doesn’t eat through the wood as fast as the skip tooth so it’s more accurate.
3 Very slowly, carefully, and deliberately cut the length of the member. Try to cut straight and if you have
to, air on the side of not cutting off enough, rather than too much.
5 Cut off the extra material by the handle of the stir stick.
6 Repeat 1-5 ad-freaking-nausea until you have 12 to 16 member blanks.
7 Slowly, over at least 3 passes, sand the rounded ends of the member.
8 Check overall length of member- 17.5 - 0.1”. No longer than 17.5”.
9 Check overall width of member- 0.5 ± 0.05”. Check in at least three places, especially towards the end
and right in the middle. If too large, sand down. If too small anywhere, break it. Throw it away.
I hate to be a hardass about that but 1) the materials are free 2) if these break, bend, or crack the
device will not function as expected.
10 If it clears QA, pass off to someone on the mill (in a perfect world).
11 Repeat 7-10 with the blanks until all blanks are ready (or passed off to someone) for milling.
!!! Why are we drilling holes with a milling machine and an end mill?
ACCURACY. Every 3/16” drill bit I could find was bent and there’s no easy way shift the piece accurately

on a drill press. Try to grab one of the mills with digital readout. The following steps will reflect the need
for accuracy. The SUPER CRITICAL dimension here is the distance between each hole and their
alignment to the central axis.
12 On a milling machine with digital readout, load a Jacobs chuck and an edge-finder. Find the left edge of
the vise and zero the X readout. Now find the inside edge of the FIXED jaw of the vise and zero the Y
readout. DO NOT FORGET TO ACCOUNT FOR THE WIDTH OF THE EDGE-FINDER.
13 Using a clamp, clamp a parallel or similar to the end of the vise to serve as a stop to preserve the datum
we just established. Avoid using a 1-2-3 block for this because of the holes.
14 Develop a clever combination of thin parallels and other mounting hardware that allows us to clamp the
members about ¾ of the way down their length for rigidity. There are too many variables here to
establish a fixed method. Critical think and have fun. The height doesn’t have to be perfect- just as close
as you can manage without it clearly being sloped.
!!! “Wow Nate this is all a huge pain in the ass”
Yes. Yes it is. But you’re about to do ~14 of these damn things and they need to be IDENTICAL.
You’ll thank me later.
15 Place blank in your shiny, fancy new fixture. Make sure you can drill the holes all the way through
without hitting any of the mounting hardware. That would be bad.
16 Move 0.2500” in from both the Y zero and the X zero. You should be centered on the end of the
member ready to drop the first hole.
17 At about 1500 rpm, drop the first hole. It should be visually obvious if it’s centered.
18 If it looks good, lock the CRAP out of the Y and zero the X on the position of the first hole.
19 Slide down 8.5000” and drop the second hole.
20 Slide down another 8.5000” (should read 17.0000”) and drop the final hole.
21 Remove the piece and check the distance between the end of the piece and the inside edge of the
holes. The distance between the edge of the hole and the edge of the piece should be 0.155 ± 0.01”.
If the first and second holes are off, something is wrong with the fixture. If the third hole is off, Player
One didn’t do their job. Yell at them.
If the reference dimension for the third hole is too large, it can be sanded down. If it is too small, this is
a critical error and the part should not be used.
22 If part is acceptable, load another and repeat steps 17-21 until you’ve acquired at least 10 parts in spec.
!!! It might be nice to have someone separate doing QA on each part so the mill operator can just keep
going.
23 If necessary, repeat all if too many parts are being scrapped.

Part Name: Static Axle Mount
Quantity: 4, consider making an extra
Material: Aluminum L stock
Weight: 0.1 ounces each (estimated)
 Horizontal band saw
 Plyers
 Milling Machine with thin parallel and 3/16” end mill in 3/8” collet
 Jacobs chuck with edge finder
 Buffing wheel (over by the turret lathe)
Notes: All dimensions ±0.05” unless otherwise stated.
# Process
1 Carefully mark the outer corner of the stock in 9/16” intervals.
2 Place stock corner-up in the horizontal band saw and align the saw with the first mark.
!!! Make 2-3 more marks and cuts than you think you need because these are the same dimensions as for
the Lower Cable Guide and the Upper Cable Guide.
3 Grip the very edge of the stock with the plyers so you don’t lose the piece about to be cut.
4 Make the cut.
5 Reposition the stock and repeat.
6 Take parts over to the buffing sander and remove burs from all edges.
7 Place a single 1/16” thin 1¼” tall parallel in the mill vise and the jacobs chuck with edge finder.
8 Place a single piece in on the parallel and against the left end of the vise, finger aligned, with the longer
side in the vise with the shorter side ready to be milled.
9 Find the edges of the part and establish them as zeros, accounting for the width of the edge finder.
10 Move in ¼” from each datum to the center of the part.
11 Drop the quill to cut a single hole.
12 Remove part and replace it with a blank, finger aligning it to the edge of the mill.
13 Repeat the cut until all mounts are cut.
!!! The mill is currently set up to make the cuts for the following parts:
-Moving Axle Channel
-Lower Cable Guide
Consider making these cuts now. Please reference their individual Process Sheets.
14 Remove all burs with the buffing wheel.

Part Name: Sliding Axle Guide
 Milling Machine with single thin parallel and 3/16” end mill in 3/8” collet
# Process
1 Carefully mark the outer corner of the stock in 9” intervals.
4 Make the cut.
5 Reposition the stock and repeat until quantity is met.
8 Place a single piece in on the parallel and against the left end of the vise, finger aligned, with the
shorter side in the vise with the longer side ready to be milled.
10 Move 3/8” in the Y direction and 1/16” in the X direction from the respective datums.
11 Lock the Y.
12 Drop the quill to cut a through hole. Be careful not to drop so low that you damage the vise.
14 Lock the quill.
15 Slowly feed the X no more than 8.875” from the starting point to create the slot for the moving axle.
16 Return to the position established in step (10).
17 Remove the part and replace it with a blank.
18 Repeat 15-17 until quantity is met.
-Lower Cable Guide
-Static Axle Mount
19 Remove all burs from the milling process with the buffing wheel.

Part Name: Spring Axle
Quantity: 1
Material: ¼” Aluminum Round Stock
Weight: 2 ounces (estimated)
 Bandsaw
 Lathe that allows for at least 4” of stock to sit safely inside the chuck + lathe tool
 1/8” wide cut off tool
 3/16” UNF external thread cutting dye and Jacobs Chuck in the Tailstock + thread oil
Notes: This is the most complicated part and should be developed by the team member most
comfortable with the Lathe and threading processes. If you have any insecurities with working
with the Lathe do NOT select this part for manufacture. All dimensions ±0.01” unless otherwise
stated.
# Process
1 Cut a piece of round stock about .25 inches longer than the 8” mark.
2 Insert stock into the lathe with as little material sticking out of the chuck as possible (no less than 2”).
3 With the general purpose tool, face both ends of the rod to 8”, checking length often.
4 Move in 0.5” with the general purpose tool and face the last 0.5” of the rod down to 0.1875±0.0005”.
5 Flip the piece around and repeat step (4).
6 Drop your RPM and apply thread cutting oil and install the thread cutting dye in the tailstock.
!!! Be certain the tailstock is unlocked and the RPM is slow enough.
7 Make the thread cut. You’ll notice that the last 3-ish threads are not complete enough.
8 Flip the dye around so the full threads are on the outside.
9 Make a final pass. Do not force the dye over the piece- it should thread on its own.
10 Flip the piece around and return the dye to its original configuration.
11 Repeat steps 7-9 on the fresh side.
12 Check the threads with a 3/16” nut. If they are unsatisfactory, scrap the part and start over.
13 Switch to the 1/8” cut off tool.
14 Cut the two end notches as described by the drawing. The tolerance on the positions of these notches is
±0.01” with the critical dimension being the distance between the notches. The tolerance on the diameter
of these notches is 0.2-0.05”.
15 Measure and mark the middle notch. Position tolerance ±0.1”.
16 With the marked position no more than 3” out of the chuck, turn the center notch. Same diameter tol’.
17 Flip the piece around and repeat step (13) on the other side.

Part Name: Fixed Spring Mount
Quantity: 2
Material: 1/16” thick Aluminum L stock
Weight: 1 ounce (estimated)
 Horizontal Band Saw
 Milling Machine
 ¼” two-flute end mill in appropriate collet
 1/16” thick, 1¾” tall thin parallel
 Jacobs Chuck and edge finder
Notes:
Let tolerances be ±0.01” unless otherwise stated.
# Process
1 Mark two 7.75” lengths of L stock on the outside corner.
2 Cut these lengths with the horizontal band saw.
3 Eliminate burs with the method of your choice.
4 Place with long side resting on parallel in the vise of the milling machine with the short side up with the
end aligned with the edge of the vise.
5 Use the edge finder to create datums at the end of the vise and the edge of the piece.
Don’t forget to account for the diameter of the edge finder.
6 Switch out the Jacobs Chuck for the ¼” Two Fluted end mill.
7 Move ¼” in to the centerline of the piece. Lock the Y.
8 Move ¼” along the centerline to the first hole. Mill it out.
9 Continue to move along the centerline cutting each hole.
10 Remove part and eliminate burs with method of your choice.

Part Name: Spring Rod
Quantity: 2
Material: 1/8” Aluminum Round Stock
Weight: 0.5 ounce (estimated)
 Band Saw
 Sander
Notes:
Let tolerances be ±0.1” unless otherwise stated.
# Process
1 Mark two 7.75” lengths on the round stock.
2 Cut these lengths with the band saw. Mind your blade and cutting speed.
3 Eliminate burs with the method of your choice.
4 Congrats that’s it.

Part Name: Lower Cable Guide
 Plyers
 Milling Machine with thin parallel and 3/16” end mill in 3/8” collet
# Process
the Static Axle Mount and the Upper Cable Guide.
4 Make the cut.
8 Place a single piece in on the parallel and against the left end of the vise, finger aligned, with the longer
side in the vise with the shorter side ready to be milled.
10 Move in ¼” from each datum to the center of the part.
11 Drop the quill to cut a through hole. Be careful not to drop so low that you damage the vise.
12 Lock the quill.
13 Unlock the X direction.
14 Slowly feed the X no more than 0.094” in each direction from the starting point to create a slot no
wider than 3/8”.
-Moving Axle Channel
-Static Axle Mount
15 Remove all burs from the milling process with the buffing wheel.

Part Name: Upper Cable Guide
Quantity: 1
 Plyers
Notes:
All dimensions ±0.05” unless otherwise stated.
# Process
the Static Axle Mount and the Lower Cable Guide.
4 Make the cut.
7 Buff the outer surface of the L to smooth the surface.
8 Be especially aggressive along the centerline and on the center of the corner to create a slight channel
for the cable. Also create slight radius on each outer edge to avoid having a running cable strip or cut.

Part Name: Occam’s Bucket
Quantity: Need one, make 2-3
Material: Cardstock paper or thin cardboard
Weight: 0.5 ounces (estimated)
 Razor, preferably of the Occam variety.
 Printer and fine-point Sharpie™
 Heavy cardstock paper or thin cardboard
 Gaffer’s Tape (preferred)
Duct or Electrical Tape (acceptable)
Notes:
We should probably make a couple out of both cardstock and thin cardboard. All dimensions
±0.05”.
# Process
1 Print off the template, either onto cardstock or onto regular paper.
2 Check the reference dimensions in both directions.
3 If necessary, scale and re-print the template, checking the dimensions again.
4 Cut out the template with a razor or box cutter. Cut the slot for the cable.
5 Appreciate my joke about Occam’s Razor.
6 Appreciate the simplicity of this capsule solution.
7 Gain new appreciation for the depth of my joke about Occam’s Razor.
8 Go look up Occam’s Razor if you’re not familiar. (tl;dr – It’s the philosophical version of K.I.S.S.)
9 Along the dotted fold lines, place a machinist’s ruler or something else thin and rigid to act as a
folding guide.
10 Carefully fold the bottom flaps marked 1 and 2 and tape the very bottom edge in place along the red
line.
!!! The flap marked with cross hatching is an internal surface for supporting the ball. It should NOT close
off the box and it should NOT be folded all the way down to meet the bottom of the box. It should be
folded to meet the RED reference line on the inside of the box.
11 Confirm step 10 by next folding the sides (3 and 4) in. Their tapered edges should align with the
bottom of the structure
12 Tape 3 and 4 in place along the bottom.
13 Fold and tape the top in place.
14 Fold and tape the cable attachment. Double tape this area for rigidity.

The Assembly Process
Screw servo head to the reel
Bolt the two parts of the servo mount together and more bolts to attach servo to the mount

Use epoxy to attach brackets, spring, and servo mount to base and top base

Use bolts and epoxy to attach the mechanical suction cup to the base
Thread sliding rod though bracket channels, with nuts, washers, tension springs, constant force springs,
and cross-members in their places like such, then screw down the constant force springs
Thread the retaining rod and snap in the spacers

Attach other side of bottom cross members and middle member bolts
Add second level of scissor members on both sides, meshing with the first

Bolt the scissor members to the top base brackets and bracket channels, with 1/16”gap leeway to make
up for imperfect rail alignment.

Sliding arm assembly
Attach the constant force spring to the mounting bracket on top of the cover
Screw the end of the spring to the back of the sliding arm, glue carbon fiber sheet on top base
Attach the bolts to the cover and bolt the sliding arm assembly to the top base

Thread the cable though the whole system

Securely tape bucket to end of cable
Tape the spring spacer to the bottom of the top base

Glue together the activation switch mount and epoxy to the top of the servo.
NOTE: Do not get glue in the switch! This may competition-day-morning RadioShack runs, where the
shop will be closed, and you may end up having only a few hours to redesign this activation mechanism.
Carefully mount the electronics hardware on the baseboard, so it looks nice 

Congrats! You’ve assembled the whole device!! Have a nice overview of the mechanics:

Movement steps and sequence
One of the goals of our design was control simplicity. There is one moving actuator, the servo, and it
controls the entire device’s function, guiding it through all the functions required.
There is a single cable running from the servo, up though the middle of the scissor lift, around to the
back of the top, through the sliding arm, and attached to the bucket so it can be lowered. This is
achieved by having both the arm and scissor mechanism spring loaded, and having gravity release the
bucket. Until reeling the bucket and arm back over the wall, the servo is only allowing the system to
extend itself, only providing resistance to release in a controlled manor.
Figure: The cable path

The servo spins, unreeling the cable. This releases the scissor mechanism upwards.
Now that the scissor lift is at the top, the sliding arm is free to slide out

After the arm fully extends, the bucket is free to descend.
After the bucket hits the table, it tips over, releasing the ball

The ball is released, the servo switches direction and the bucket is reeled back up

After the bucket reaches the top, the arm slides back in, completing all of the tasks.
The machine is fully retracted as designed. (The scissor can be pulled down, but it’s hard on the servo
and not part of the competition, so we don’t bother)

Our electronic system
Our electronics consist of an Arduino Micro, a switch for selecting running mode, a button to start the
device, and a servo to move the device.

Picking though long strings of code is tedious, so here is a summary of our Arduino program:
Note: all of the actions in the green circles are achieved by reeling out, or reeling out and then back in,
respectively, the servo motor.

Critical Design Elements
All of these concepts were mentioned previously, so they will not be explained again, they’re just here
as a neat summary.
 Scissor lift with assist spring
 Sliding arm
 No-mechanical-parts tipping bucket
 The simple control mechanism with a single servo motor and single cable
 The mechanical suction cup mounted on the bottom of the device to keep it secured to the
table
Cleaver and Possibly Unique ideas
We feel that the suction cup is probably going to be unique. It does a wonderful job of keeping our
device were we intend to put it and requires very little time to attach. It was a good and simple addition
to the design.
The tipping bucket also seems an idea worth noting. It works well and we haven’t seen any other groups
using even a similar concept. They all have buckets that are dumped, which requires moving parts and is
less precise.

H - Bill of Materials P a g e | 112
H - Bill of Materials
Stock
#
Description Material Where Purchased Quantity Used
Cost
Each
($)
Used
Cost($)
Cost
Total
Item# Item Name Item Quantity Item Description
1 #10 Washers Steel HOME DEPOT 50 32 0.035 1.12 1.75
2
#10-24 UNC
machine screws
Steel HOME DEPOT 20 10 0.105 1.05 2.1
3
#10-24 UNC
bolts
Steel HOME DEPOT 40 20 0.052 1.4 2.08
4
LOCTITE Epoxy,
0.47 oz
Epoxy HOME DEPOT 2 1 5.12 10.24 10.24
5
#10-24 UNC
threaded rod
Steel HOME DEPOT 1 1 3.19 3.19 3.19
6
1/16” x36” L
Stock
AL HOME DEPOT 3 3 4.57 13.71 13.71
5-1 Bracket 1 1
Holds cable down near base of machine after
unspooling from servo and before interfacing
with Bracket 2.
5-2 Bracket 2 1
Guides the cable to the top towards the
Bracket-3
5-3 Bracket-3 1
Holds the cable at the bottom of top base
and lead it towards the Bracket 4
5-4 Bracket-4 1
Moves the cable to the top of the base and
guides it towards the sliding arm eventually
leading it to the bucket.
5-4
Arm
channels
8
Provides bound region for the sliding half of
the scissor members to travel through
7
21x2x0.25” paint
sticks
Wood HOME DEPOT 6 6 0 0 0
8 2’x4’x0.25” birch BirchPly HOME DEPOT 1 1 10.91 10.91 10.91
8-1 BirchPly-1 Home Depot Used to make the base of device
8.2 BirchPly-2 Home Depot Used to make the top of the device
H

9
5.5” by 2.06”
compression
spring
Spring Steel
CenturySpring.com,
part #5089
1 1 7.13 7.13 7.13
10
4.94” by 0.219”
extension
springs
Music wire
CenturySpring.com,
part #1839
4 4 3.15 12.6 12.6
11
0.5” by 24”
constant force
spring
Music Wire
CenturySpring.com,
part #CF148
1 1 2.21 2.21 2.21
12 Ardino Micro
Silicon and
magic
Adafruit.com 1 1 24.95 24.95 24.95
13
Retractable Dog
Leash
Fabric/ABS Petco 1 1 19.99 19.99 19.99
14 22 gauge wire Copper RadioShack 1 1 9.49 9.49 9.49
15
Mini Roller
Switch
ABS/AL RadioShack 1 1 3.49 3.49 3.49
16
2xAA Battery
Holder
ABS RadioShack 1 1 1.99 1.99 1.99
17
Mini Leaver
Switch
18 10K Resistors Silicon RadioShack 10 1 1.49 0.149 14.9
19
Solderless
Breadboard
20 Heat Shrink Tube Plastic RadioShack 100 10 15.99 1.599 15.99
21
11x14x0.093”
Sheet
Acrylic Home Depot 2 1 12.99 12.99 25.98
21-1 Sliding Arm 1
Moves out of the scissor lift and covers the
horizontal distance with bucket hanging
21.2 Arm Cover 1 Defines the path for and secures arm
22 Section Cup ABS/Rubber Ebay 1 1 9.99 9.99 9.99
23 Key Return ABS Ebay 1 0 3.99 0 3.99
24 6X1/2” Screws Steel Home Depot 50 16 1.94 1.94 1.94
25 Basic Sponge Sponge Home Depot 1 1 1.00 1.00 1.00
26
Extension
Springs
Steel Home Depot 4 4 3.15 3.15 12.60
27
0.5”X24Constant
Force Springs
Spring Steel Home Depot 4 4 2.21 8.84 8.84
28 Aluminum Sheet Aluminum EMECH Bins 2 2 0 0 0

29 Ping-pong ball Plastic Walmart 1 1 0.50 0.50 0.50
TOTALS 176.388 235.04
Calculated from the above table, money spent on…
 Total:$235.04
 Cost of used material: $176.39
 Spares: $12.99
 Parts we didn't end up using:$ 3.99
 Things that broke: $0
 Things we already had: $0 (by definition!)
Figure H1: The Arduino arrived almost broken, but we were able to bend the pins back!

I - Testing P a g e | 115
I - Testing
Test Plan Document
Scope: To test each subsystem of the device, and the entire functionality of the device. Testing will allow
our group to identify design faults that need to be fixed. Each test will incorporate specifications from
the QFD in order to gage how close we are to a value.
Features to be tested:
1. Scissor Lift
2. Extending Arm
3. Servo
4. Arduino
5. Bucket
6. Suction Cup
Device Dimensions: Our device is maxing out all dimensions at 11” deep x 18” wide x 3.5” tall
Weight: 2.95 lbs.
Scissor Lift Extension Test
Systems Tested: Scissor Lift, Servo, Arduino Switch
Test Description: The device was collapsed with all the parts assembled on the device and the ball was
put into the bucket. The device was then activated when the Arduino activated the servo to extend line.
The initial height, final height, time to cover distance, and wobble at the top were all recorded. It was
then collapsed down and repeated.
Materials Needed: Tape Measure, Stopwatch
Date of Test: April 15, 2015
Target
Test
1
Test
2
Test
3
Test
4
Test
5
Test
6
Test
7
Test
8
Test
9
Test
10 Reliability
Standard
Deviation
Starting
Height (in) < 3.5 3.063 3.25 3.75 3.5 3.5 3.5 3.75 3.5 3.5 3.5 80% 0.2042
Time
Vertical
Distance(s) <10 7 6.2 6.5 7.2 7.46 6.87 6.5 6.87 6.3 6.5 100% 0.4068
Height
Extension
(in)
>24
<32 29 29.25 29.5 29.75 28.25 29.5 29.5 29.5 29.5 29.5 100% 0.4257
Wobble at
top base
extended
(in) 2 2.25 2.5 2.25 2 4 2.5 2.5 2 2 2.5 90% 0.5869
I

Summary: The scissor lift extension test showed that the device ascends every single time to a correct
final height when triggered by hand. The only downfall to this test is that the autonomous start switch
has not been completed yet. Once this is manufactured, the entire reliability of getting the device to
ascend on the actual test fixture can be tested.
Autonomous Start Test
Systems Tested: Arduino Switch, Arduino Switch Mount
Test Description: The device will be placed in the starting zone in 20 seconds by a group member. The
bar will then be lifted up and back to the second zone which will then trigger the circuit.
Material Needed: Device, Stopwatch
Date of Test: April 16, 2015
Summary: The autonomous start switch functions 80% of the time when placed on the test fixture. The
switch was not activated 100% of the time due to the large amount of wobble experienced by the
mount. To address this issue, we are going to look at the failure mode, and determine a potential
redesign of the switch mount.
Autonomous Start Switch Test
Testing
Criteria Target
Test
1
Test
2
Test
3
Test
4
Test
5
Test
6
Test
7
Test
8
Test
9
Test
10 Reliability
Standard
Deviation
Time to
Place
Device
20 38 31 35 29 26 25 22 26 21 22 100% 5.72
Device
Activated
Y Y Y Y Y Y Y N Y N Y 80% N/A
Mount
Wobble
<0.25” .16 .20 .21 .23 .27 .25 .28 .24 .30 .29 60% .045

Starting Height Test
Systems Tested: Scissor Lift, Bucket fit while collapsed
Test Description: With the device fully extended, the switch is then activated, and the lift is manually
guided down by hand.
Material Needed: Device, Tape Measure
Target
Test
1
Test
2
Test
3
Test
4
Test
5
Test
6
Test
7
Test
8
Test
9
Test
10 Reliability
Standard
Deviation
Starting
Height
(in) < 3.5 3.063 3.25 3.75 3.5 3.5 3.5 3.75 3.5 3.5 3.5 80% 0.2042
Summary: The starting height was variable on the procedure used while the device was being collapsed.
If the sliding arm was extended at all, then the bucket would not fit properly in the device, and would
cause it to have a higher starting height.
Sliding Arm Test
Systems Tested: Sliding Arm, Scissor Lift, Servo
Test Description: The scissor lift was extended to full height, the sliding arm was activated, and the
resulting distance traveled and time to reach distance was recorded.
Materials Needed: Device, Stopwatch, Tape Measure
Summary: The sliding arm was activated 100% of the time, but the horizontal distance covered by the
device was never enough to allow it to reach the license plate holder. In order to fix this, we will look the
FMEA, and draft ideas.
Testing Criteria Target
Test
1
Test
2
Test
3
Test
4
Test
5
Test
6
Test
7
Test
8
Test
9
Test
10 Pass/Fail Reliabilty
Standard
Deviation
Sliding Arm
Activation
Y Y Y Y Y Y Y Y Y Y Y Pass 100% N/A
Distance traveled by
horizontal arm (in)
>5
< 9
3.2 2.7 3.1 3.2 2.9 2.8 3.2 3.1 3.1 3 Fail 0% 0.177
Time to reach final
distance (s)
<3 1.2 1.1 1 1.1 1.1 1 1 1.2 0.9 0.8 Pass 100% 0.126
Sliding Arm Test

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