Senior Design Final Report

MEE 472: Synthesis of Mechanical Systems II
Gate 3: Final Report
Syracuse University
College of Engineering
Final Report
Theodros Belay, Patrick Carney, Alexander McGlone, Benjamin Rosenfeld, Yvline Tanis
May 11th, 2016
Supervised by
Prof. Frederick J. Carranti, Dr. Michelle M. Blum

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Abstract
Tasked with creating a device to retrieve, sort and deposit various balls, team one has used the
previous year to research, design and manufacture the various system components that will
made up the ball harvester mechanism. The Final Gate 3 report explains the accomplishments
of team one throughout the entire 2015-2016 school year and the success of the team’s ball
harvesting machine. Discussed within the design approach section of the report are the design
process and steps that the machine underwent until the final model. The design of the machine
underwent many changes since the beginning of the fall 2015 semester. All five systems that
make up the mechanism are assessed within the component and hardware section of the
report. These systems are the feeder, sorter, storage, movement and controls. Each system
played a vital role in the performance of the machine. Within the advanced modeling and
system simulation section, the usefulness of solid modeling in the design of the machine is
talked about. The team utilized many experiments when designing the machine in order to
assess the potential functionality. In the testing and experimentation section, these
experiments will be elaborated on. In the demonstration and performance section, the team
will describe how the machine performed on demonstration day on the given objective. Finally,
the conclusion section will summarize the entire report, the ball harvesting mechanism and
team one’s experience in senior design.
Figure 1: Displays team one’s variety ball harvesting
machine as used on demonstration day.

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Table of Contents
Abstract..........................................................................................................................................................i
Introduction ..................................................................................................................................................1
Problem Background.................................................................................................................................1
Design Approach...........................................................................................................................................3
Generation of Candidate Concepts...........................................................................................................3
Identification of Components & Hardware...............................................................................................5
Development of Preliminary Methods & Optimization of Models...........................................................7
Selection of Design....................................................................................................................................8
Components & Hardware .............................................................................................................................9
Feeder System...........................................................................................................................................9
Generation of Candidate Concepts.......................................................................................................9
Identification of Components & Hardware...........................................................................................9
Development and Generation of Preliminary Models........................................................................10
Sorting System ........................................................................................................................................13
Storage System .......................................................................................................................................17
Movement System..................................................................................................................................20
Controls System ......................................................................................................................................23
Development of Preliminary Analytical Models .........................................................................................26
Advanced Modeling & System Simulation..................................................................................................29
Testing & Experimentation .........................................................................................................................31
Production & Manufacturing......................................................................................................................33
Demonstration & Performance ..................................................................................................................34
Design Assessment......................................................................................................................................36
Requirement Achievements ...................................................................................................................36
Product Enhancements & Life Cycle Analysis.........................................................................................36
Project Management Timeline ...................................................................................................................38
Economic Analysis.......................................................................................................................................39
Cost Considerations ................................................................................................................................39
Sales and Profit Consideration................................................................................................................40
Society and Environmental impacts............................................................................................................41

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Conclusion...................................................................................................................................................42
Project Responsibilities...............................................................................................................................43
Works Cited.................................................................................................................................................46
APPENDIX....................................................................................................................................................47
Appendix A..............................................................................................................................................48
—SolidWorks Drawings—.......................................................................................................................48
Feeder System:....................................................................................................................................49
Sorter System:.....................................................................................................................................54
Storage System: ..................................................................................................................................58
Movement System:.............................................................................................................................69
Appendix B..............................................................................................................................................74
—Arduino Code—...................................................................................................................................74
Appendix C..............................................................................................................................................85
—Bill of Materials—................................................................................................................................85
Appendix D..............................................................................................................................................87
—Gantt Chart— ......................................................................................................................................87

Introduction
Problem Background
The purpose of this project was to design and build a mechanism capable of gathering, sorting,
storing, and depositing a variety of balls into a basket. These balls included tennis, golf and
lacrosse balls. This is a team-based project and each team was required to have a fully
functional ball harvesting machine by the assigned demonstration day. On this day, each team
was assigned per run which type of ball needed to be collected. There were 25 balls of each
type. Furthermore, constraints were laid upon each team in the design, manufacturing and
demonstration of the devices specified in the project statement. These constraints included a
size limitation, budget and time limit for each demonstration run. The machine’s size limit was
9”x11”x17”, as it needed to fit within a box of those dimensions. The budget was $250, though
a team could spend more out of pocket if desired. The time limit for each demonstration run
was two minutes. Additionally, each machine needed to be powered by a non-hazardous
energy source.
Team one decided that the machine could be divided into five separate systems. These are the
feeder, sorter, storage, movement and control systems. The feeder is a conveyor belt inspired
design, utilizing four rotating sprockets and two E-chains with fin-like plows attached to pick up
the balls. It works in conjunction with a curved ramp so the balls can easily roll up the front of
the device. The sorter uses two methods to distinguish between the three ball types, by weight
and by size. Then a small servomotor provides the mechanical motion to either store or release
those balls. The storage component supports the sorter and can be raised and lowered with a
scissor lift driven by a lead screw. The balls are stored within a container having a false floor. A
door in the back opens to release the balls when necessary. The movement system design is
unique possessing wheels and a sled. It is front wheel drive with each wheel being independent
of the other. As such, the movement system contains two motors. The sled is located at the
rear of the machine and is curved upwards at a 30 degree angle. It possesses a large surface
area to distribute the load of the machine and is able to slide and pivot on turf. Finally, an
Arduino Uno combined with various shields were chosen to create a multilayered module,
allowing for remote control of the device. Each component of the device was designed with the
other systems in mind in order to ensure that they will perform well when assembled. The final
machine was given the name R.O.B.O.D, standing for “Remotely Operated Ball Organizing
Device”.
The last time the team constructed a report, the team was still working on using treads for the
movement system and pulleys and a conveyor belt for the feeder system. Prototypes of three
components had been developed, but only one was built upon and used in the final machine.

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This was the sorter. The prototypes of the movement and feeder systems were eliminated. A
general purposed idea with significant 3D modeling was presented and a basic budget list had
been composed. Basic calculations had also been performed to give a general idea of how the
machine would operate on demonstration day. Since then, the team completed the project
objective of successfully building a functional variety ball harvesting machine. Each component
of the machine was built and assembled together and the code to control the R.O.B.O.D and its
various components was perfected. The movement and feeder system methods were changed
and the scissor lift used in the storage system was finally manufactured. SolidWorks models and
professional drawings for nearly all of the R.O.B.O.D’s parts were finalized and brought together
in an assembly. Finally, team one’s device performed outstandingly on demonstration day.

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Design Approach
Generation of Candidate Concepts
Before team one devised a final solution to the problem, there were several design concepts
that were generated and critiqued on for improvement. Although these solutions each shared
the main focus of determining how the device was going to collect, sort and deposit the balls,
each system had its unique characteristics. For example, take the design concept that utilized
suction. A rough summary of how this concept would work is that a ball would first move into
the machine along a ramp and a suction mechanism would move the ball along to
compartment two. Then the paddles at compartment two would incase the ball and the sensors
would relay certain information depending on how much the springs on the paddles
compressed which varied with the different ball diameters.
In this next concept, one of the major design differences was the use of scissor jacks. The
scissor jacks would first be compressed and then extended using a motor that would lock the
balls into place. The sensors would then measure the amount of compression the springs
underwent, which in turn would be how the system differentiated each ball. The material
would create enough friction at the paddles to prevent each ball from slipping, Once the balls
are located in the hooks, the grappling system would rotate clockwise using a conveyor belt to
the other end of the mechanism and stop for a moment at an angle facing the basket. This can
be seen in Figure 3 on the next page.
Figure 2: Displays the first concept of using suction to pick up the
balls.

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Lastly, another solution that was devised by group one was a horizontally rotating feeder
concept. The feeding system would have a rotating feeder designed with two rotating shafts
with rubber wheels attached to each of them. These rubber wheels would possess fins that
would pull the balls in. Essentially, it would be the force created by the two opposing motion
shafts that would drive the ball inwards as shown below to the left. The conveyor belt is
another key feature in this concept as it helps move the ball along into the system.
Upon further inspection of each design, the team
realized that the concepts had a few flaws. One said
flaw was that the collection and sorting mechanisms
were not plausible to accomplish the goals of the
project. Another flaw, there was not much thought as
to why the specific movement system was chosen or
the best way to build it. As such, none of these
concepts made it into development. Overall, all of these
concepts were good initial ideas which helped lead the
team to the final design solution.
Figure 3: The grappling concept developed by Team 1.
Figure 4: This concept was similar to
the feeding method Team One used
in the final design.

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Identification of Components & Hardware
After team one eliminated the earlier concepts, the
team was able to generate a more concise design. As
this point, the team realized the best approach to
obtaining the solution would be to breakdown the
system into five unique components. These five
components would then be assembled together. The
machine would be controlled by an Arduino Uno,
powered by batteries and receive commands from a
wireless remote controlled by a human operator. This
design was constructed via the requirement brought
forth by the team stating that a simple yet effective
machine was required. A basic sketch of this concept
can be seen in Figure 5 and the following will talk
about the multiple systems that compose the machine.
Feeding System: Located at the front of the machine is a rotating conveyor belt with plows
attached. The plows are angled to scoop and center the balls as they are brought towards the
top of the machine and will rotate counter-clockwise. This can be seen in Figure 5. The distance
between the plows and the front of the machine body must be less than half of the diameter of
the smallest ball and the total distance must allow for entry of the largest ball. The plow
attachment point to the belt must withstand the weight of the heaviest ball and not twist. The
belt will most likely be made of a rigid material forming a linkage system, allowing it to obtain
curved motion over the pulleys, but strong while picking up balls. The feeding system must also
be powered by a motor, which will either be located in the base of the machine or on the
pickup itself. The conveyor belt must also be tensioned correctly to allow for proper tracking
and prevent the belt slipping. This will be accomplished by having one of the pulleys adjustable,
acting as an idler, so the belt can be slipped on and then properly tensioned.
Sorting System: To make the challenge for picking up one particular ball on the test day easier,
it was decided to pick up all balls and then sort them in the machine. The sorting system used
will be placed immediately after the pickup system, where the ball will roll and be analyzed by
weight, color, or size. The goal balls will be deposited into the bed of the machine while the
others will be rejected back onto the field by means of ejection. All three ball types will be pre-
programed into the system before the test, and the goal ball chosen while the test is being
performed. The sorting system is going to be made as small as possible so that the room for the
storage system can be maximized.
Figure 5: This concept lead to the final
design solution of the R.O.B.O.D.

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Storage/Deposit System: After the balls have been sorted, the objective balls are dumped into
the storage part of the machine, which is essentially an open container. The storage system will
take up the majority of space on the machine to maximize the amount of balls that will be
picked up. The storage system will also have a deposit system integrated so to be able to
deposit the balls into the receptacle. Because the receptacle is higher than the dimension
constraints of the machine, a lift system must be incorporated in order to raise the dump high
enough to deploy the balls. It was will this thought that two scissor jacks will be utilized to raise
the dump at an angle. The reason for choosing scissor jacks is that they take up relatively small
space and can be analyzed as a linkage system, so they will be easy to understand. The larger
scissor jack will be placed near the front of the dump and the smaller one near the rear. The
placement and size of the scissor jacks will determine the height of the dump as well as the
angle.
Movement: In order to keep within the size constraint but not to lose traction on the playing
field, it was proposed that a tread system be utilized to move the machine. The reason being
that tread gives a large amount of contact with the ground but also can have small driving
wheels, thus cutting down on space utilized but not hindering the performance of the machine.
Power/Control: The power and control of the machine will be built into its base. Batteries will
power all the electrical hardware and will most likely be high voltage, low current. High torque
low speed electric motors will provide rotational motion for the pickup system and low torque
high speed for the movement system. This will also be the location of the Arduino board that
will be the brains for the entire machine.

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Development of Preliminary Methods & Optimization of Models
Figure 5 from the previous section played a significant role in that it was the design in which the
Team chose to expand on as a means to obtaining the final solution. Figure 6 depicts the
preliminary 3D model of the overall design concept.
As previously stated, the design would be broken into subcomponents. The leftmost image in
Figure 7 depicts the feeding system. Using a windmill-like shape and conveyor belt design, this
component would be the crucial system that would serve to pick up the balls. It would use two
pulleys; one would act as a drive pulley powered by a motor, while the other would act as an
idler and keep the belt taught by being adjustable. The center image is the frame of the
movement system’s frame. The plow on the front was made to work with the feeder system to
pick up the balls. The rightmost image represents the movement system, which was a tread
design at the time.
As stated in the proposal, the surface of the testing space is a special type of turf that replicates
grass and dirt. The team considered how much traction wheels could actually provide the
machine with. Thus, it was decided that treads are used as the movement component since
they could not only provide great traction, but maintain a small profile. Additionally, treads
Figure 6: The team’s first design of the
R.O.B.O.D was very similar to the final
product.
Figure 7: These basic concepts lead to the development of the same systems for the final product.

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would allow the machine to pivot in place. In terms of the control, the team would use an
Arduino circuit board to communicate with the system.
Selection of Design
After several tedious months of researching, designing, and making improvements to the
system, team one finally obtained a final solution to the problem. The team still maintained the
five components in order to efficiently solve the problem, but was able to advance or alter each
one. The team selected the design based on what was thought would perform best.
There were major improvements made to the feeder system, sorter system, and movement
system respectively. Instead of using the conveyor belt and pulley mechanism, the team used
two sets of E-chain linkages. The windmill concept still remained, except that the team now
used uniquely 3D printed plows to retrieve the balls. This method was much more feasible with
the team’s allotted resources and constraints. The sorting system would now distinguish the
balls not only by weight by using a force sensitive resistor, (FSR), but also by size using an
optical sensor. Another new addition to the sorting system was the claw to hold the balls once
received by the feeder. The movement system underwent the most amount of changes.
Because the treads ultimately took too much time, money and effort to construct, team one
redesigned the movement system to compose of two wheels in the front, and a uniquely
designed sled in the back.
The design of the storage system relatively remained the same, with some of the major changes
being a latch mechanism and counter weight. In addition, the scissor jacks were intricately
designed to support and lift a fully loaded storage container when it reached time to deposit
the balls into the basket. In the selection of the final design, team one ultimately used a multi-
layered Arduino Uno module. The layers consisted of an Arduino Uno board, proto shield,
motor shield and Bluetooth shield. In order to achieve the final design, most of the parts were
3D printed, a few machined and others bought. After a year’s worth of much work and effort,
the Remotely Operated Ball Organizing Device or R.O.B.O.D. for short, finally came to life.
Figure 1 on Page i in the Abstract displayed the team’s final ball harvesting machine.

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Components & Hardware
Feeder System
Generation of Candidate Concepts
As the feeder unfolded in its mechanical design many stages of testing was required for the
team in order to mitigate issues that may arise. Initially the team was able to obtain two
aluminum pulley stocks that span 4 inches in length, .44 inches in diameter and .080 inches
(MXL) in pitch. With these pulley stocks the team was also able to obtain a conveyor belt of
.080 inch (MXL) Pitch, 124 Teeth, and 0.25-inch-wide Neoprene Body with fiberglass
reinforcement as shown in Error! Reference source not found.. The general specifications for
both the pulley stock and conveyor is Since the conveyor belt supplied was 0.25 inches wide,
we gathered 12 individual pieces to span the 3 inch width for the designated balls to travel up
against. The issues that had come about was finding a method to attach the external metal fins
necessary to scoop up the various balls and the ability of the conveyor belt to fully function
with induced loads.
Identification of Components & Hardware
From this point the team had transitioned to a second phase in this conveyor belt feeding
mechanism. With the kind assistance of John, an engineer at JJ Associates, the team was able to
receive brand new parts to design a more efficient robust conveyor belt mechanism. JJ
Associates is a company that specializes in aluminum, steel and plastic pulley stocks in all
pitches. They engage in specific machining such
as special bores, counter bores, keyways, double
pulleys, and special width pulleys. Furthermore,
JJ Associates supply a full line of belting products
from flat to timing belts, round belts, Mylar film
belts, stretch belts, poly-v, special cover and
perforations. To that extent, John provided the
team with two brand new aluminum pulley
stocks for free along with a conveyor belt
specially cut and made to span the 3 inch width
necessary for our feeder mechanism. The
Figure 9: Belt and Pulley System
Figure 8: Displays the conveyer belt and pulley stock
teeth specs.

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conveyor belt is a neoprene- coated fiberglass fabric that is uniquely composed of synthetic
rubbers. It has excellent mechanical strength, high resistance to weather, low flammability,
good resistance to chemicals and moderate oil resistance.
The two aluminum pulley stocks span 9.1 inches in length. The team was able to take one of the
pulley stocks to the machine shop and saw it in half. Next, the Team used the lathe machine to
turn both ends of the pulley stocks down to a 0.25-inch diameter with a shaft length of
approximately 0.5 inches. With two brand new machined pulley stocks, the conveyor belt was
ready to be put to use. For maximum efficiency and functionality, the conveyor belt had to be
tensioned by placing the pulley stocks 4.6 inches apart. With the design constraint in mind, the
framework for the feeder system also began to unfold.
Development and Generation of Preliminary Models
The generic framework of the feeder was initially designed in SolidWorks. Once designed to
meet the required specification, the model was converted to a STL file ready to be 3D printed.
With the aluminum pulley stocks machined to the appropriate length, the team began to
assemble the various components to form the conveyor belt mechanism. The 12V DC motor at
our disposal consisted of a 1⁄8-inch shaft diameter which required the team to order a coupler
from Servo City. This coupler joined the motor’s 1⁄8-inch shaft diameter to the 1⁄4-inch
diameter pulley stock shaft. The conveyor belt mechanism was then integrated with the
framework of the feeder allowing the team to go directly into the testing phase.
Unfortunately, once the motor had
been mounted to the 3D printed frame
and supplied a 12V battery source, the
conveyor belt mechanism did not
rotate. It was observed that the pulley
stocks induced such a heavy load that
the motor could not provide enough
torque to rotate it, indicating that the
motor simply was not powerful enough.
While this was an issue the team had
simultaneously been working on an
alternative concept in case of such an
unforeseen circumstance. The team
had invested in a concept known as E-
Chains.
E-Chains are said to be the umbilical cord of modern machines. They minimize downtime,
protect, support and extend the service life of cables and hoses. Though the intended purpose
Figure 10: E-chain and Sprocket Mechanism

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of these E-chains was meant for the protection and support of cable wires and hoses the team
had a different approach in their use. The E-Chains are light in weight and incorporate slots in
its design which the team thought would be beneficial to attach external materials to scoop up
balls as opposed to the conveyor belt mechanism. Through geometric analysis the team was
able to design a custom fit sprocket to mesh with the E-Chains and 3D print it for testing. With
this new design, former risk factors which had risen from the conveyor belt mechanism have
now been mitigated.
Once meshed with the E-Chain, a 2 1/4” aluminum axles were used to run through the center
holes of the 3D printed sprockets. The aluminum axles were held in place by L-Brackets that
were designed and 3D printed as well. These L-Brackets were made to incorporate a total of 4
bearings, 2 pressed fitted on each side of the respective L-Bracket. These bearings served a
purpose in providing a frictionless rotation within the feeder design. The 12 DC stepper motor
obtained to drive the feeder was mounted on the internal surface of one of the L-brackets, just
below the rotating the sprockets. Once mounted the team had introduced a concept in which
gears were used to provide a point of connection between the axle of the motor shaft to the
axle running through the top set of the sprockets. A gear train was formed and attached
externally to the feeder with spacers in between as well as collars with built in set screws.
These collars held the gears in place and prevented any risks of the gears possibly sliding of the
aluminum axle.
Throughout the multiple testing stages in the feeder’s scooping up abilities, a final plow design
was selected as the ideal approach in picking up the various balls set on the field. These set of
plows were made to have a divot along its center line as well as angled appropriately for
transference capabilities between the feeder and the sorter. The plows also have two 1 set of
holes evenly spaced to mount onto the E-chains directly. Initially, hot glue was used for testing
purposes, but the final design incorporated a set of bolts and nuts as a form of attachment for
the plows.
Overall the feeder’s scooping capabilities have shown great strides and results. Once attached
to the movement, it was carefully leveled to have enough clearance to pick the various balls set
on the turf. The team later discovered that the sharp corners designed for the L-brackets
caused the machine to dig into the turf. This action then in turn slowed down the robots
moving and scooping abilities. As a form of mitigation, the 4 corners formed by the base of the
feeder were carved out and rounded. WD-40 and MonoKote also became supplemental
mitigation factors in reducing any opposing forces such as friction while the feeder was
operating. MonoKote is a lightweight plastic shrink wrap that the team used to cover the ramp
and WD-40 is a trademark lubricant that the team used to coat the plows. These developments

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in the feeder design increased the success rate in accomplishing the underlying goals of the
team’s ball harvester mechanism.
Figure 11: The final feeding system. Not pictured
are the gears and motor used in the assembly.

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Sorting System
The original strategy to sort between the three balls was to distinguish them by size. This idea
fell through, as the tennis and lacrosse balls happen to be very similar in size so there may be
some error in distinguishing between the two. The second strategy was to differentiate the
balls by their weights. This led to one of the main components of the sorting system being
purchased; a Force Sensitive Resistor (FSR), which is essentially a circuit whose resistance
changes when an applied force is increased or decreased. The FSR is accurate enough to
distinguish between all three ball types when the system is under static conditions and can
withstand a load of up to 22lbs, making it an ideal sensor to perform the task. However since
the device will be moving around this will cause the balls to experience dynamic conditions.
This could cause errors in the ball detection method, so the team then decided that there
needed to be two sorting procedures to accurately determine what ball is in the sorter. For this
reason an Optical Sensor was chosen to distinguish the balls by size. The optical sensor is placed
at a height so that it could see the tennis and lacrosse ball, but not the tennis ball. Therefore if
the FSR detects weight but the optical sensor does not see anything, then it knows that there is
a golf ball present. If the FSR detects weight and the optical sensor sees a ball, then there can
either be a tennis or lacrosse ball in the sorter and will be distinguished by its weight signal.
The structure of the optical sensor is quite small relative to the project
itself, having dimensions of .5”x.65”x.18”. There is also a convenient
hole made for mounting the sensor on a surface. Protruding from the
rear of the sensor are four wires corresponding to power (5V, red),
ground (black), signal (green), and another ground, which can be seen
in Figure 12. This first wire powers an infrared emitter, and the signal
wire receives data from an infrared detector. The sensor works by
producing an infrared light from the emitter, and if an object comes
close to the emitter it will reflect some of the infrared light back
towards the detector. The closer the object moves towards the sensor
the stronger the signal will be. It should be noted that the optical
sensor is an analog device, meaning that the signal generated by the
sensors’ detector can have values between 0 (complete reflection) and 1024 (no reflection).
Since the purpose of the optical sensor is to distinguish between a golf ball and the tennis and
lacrosse balls, it can be treated as a digital device. By this it is meant that it will have either one
of two values; a high value if the golf ball or no ball is present in the sorter and a low value if
the tennis or lacrosse ball is present. A value of ranges will be chosen for both scenarios to
account for tolerance.
The Force Sensitive Resistor (FSR) is also an analog device and is not much smaller than the
diameter of a quarter. It only requires power from the 5V pin on the Arduino and to be
Figure 12: The Optical
Sensor used in sorter.

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connected to both its ground and an analog pin. A resistor is
used to tie the FSR to ground and the difference in
resistance between the analog pin and ground is used to
determine the weight of the balls. A picture of the FSR can
be seen in .As the balls inside the sorter will experience
dynamic movement, and because the sensor takes a brief
period of time to ‘settle’ on a value, an averaging algorithm
has been written into the Arduino code with a ‘check’
statement in order to insure proper measurements of the
ball’s weight. This algorithm can be seen in the Arduino
code located in the appendix of this report.
Using the FSR and the optical sensor together allows the device to able to distinguish between
the balls easily, as the balls can be categorized via the following way:
Ball Type FSR Value Optical Sensor Value
No Ball 0 – 200 > 800
Golf Ball 200 – 400 > 800
Tennis Ball 200 – 400 < 800
Lacrosse Ball > 400 < 800
In order to ‘tell’ the sorter which ball is the objective ball, the ‘square button’ on the PS3 (Sony
PlayStations 3) controller can be pressed and, depending how many times it was pressed, it will
sort one of the three balls. In order for the team to have visual acknowledgement that the
device will sort the required ball there will be three different colored LEDs mounted on the
frame of the device. Each LED will correspond to a particular ball and will light up if the sorter is
looking for that ball. A circuit diagram of the sorting system, generated with the use of the
Fritzing software, can be seen in Figure 14.
Figure 13: Force Sensitive Resistance
and 10kΩ Resistor.
Figure 14: Circuitry for Sorting Component,
Design in Fritizgn

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The sorting component must be able to physically move the balls in order to store the objective
balls and discard the unwanted ones. A small, metal geared and high-torque servomotor will
perform this movement. Sold by Adafruit this micro servo can produce up to 30.5 oz.-in of
torque at 6V, more than enough to move a lacrosse ball at a distance of 1 inch away from the
servo. The servo is advertised to be able to move between 0 and 180 degrees, however
realistically the motor can only operator between 15 to 165 degrees, but this does not impact
the sorting process. The motor is also extremely light at 13.4 grams and can turn as fast as 60
degrees in .08 seconds when unloaded. One important fact to note about this servo is that it
will hold its position when there is no signal being applied which was a key feature when
writing the code to control the sorting component. A sample picture of the servo can be seen in
Figure 16.
The mechanical structure of the sorter is composed of three different pieces; the main frame, a
movable platform (ball palette), and a claw. The frame of the sorter is designed to attach to the
front of the storage component with two ¼” machined screws and nuts. The frame includes
mounting points for the servo and a hinge that will assemble the frame and the palette
together. The frame is designed so that all unwanted balls roll down a ramp and off the side of
the device. The ramp is already integrated into the sorter frame and can be seen in Figure 15.
All three pieces of the sorter will be 3D printed with ABS plastic due to its attractive mechanical
properties. The sorter frame was designed to accommodate all three ball types without
Figure 15: Modeled Sorting Component. Views from Left to Right: Isometric, Right Side, Back
Figure 16: Image of Micro Servo, Exterior and Interior

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jamming or entry mishaps. It has a length of 4.5 inches, which allows for enough space to house
a lacrosse ball while having the servomotor in place. The thickness of the sorter is .4 inches,
which gives its structural rigidity. An extruded portion in the middle of the frame with a cut out
silhouette of the FSR allows for a perfect placement of the sensor.
The ball palette is designed to attach to the frame with the addition of a hinge that allows the
palette to move down when a ball rolls onto it. The palette has a ‘foot’ that rests on the FSR,
allowing a uniform force to be loaded onto the FSR. The foot was given a 5-degree angle so that
it may lay flat on the FSR.
The sorter claw is designed to be wide enough to allow a tennis ball in and will attach directly to
the servomotor. Currently the claw is only a pressure fit on the servo however a design to allow
the claw to be attached with a setscrew is in the works. The claw also has a cutout on the top to
allow the optical sensor to be placed at the ideal height.
The final cost for this component comes in at $19.30. This is because all the electrical
components are extremely cheap relative to some of the other materials needed for this
project, and 3D printing is free. The optical sensor was also a free piece as it was repurposed
from another project. The total budget for the sorting component can be seen in the table
below.
Description Price Quantity Total Price
FSR $7.00 1 $7.00
Servo Motor $9.95 1 $9.95
Hinge $1.25 1 $1.25
M2 Screws $0.15 4 $0.60
¼” Screws $0.25 2 $0.50
ABS Plastic Free 2 oz. Free
Optical Sensor Free 1 Free
LED Free 3 Free
Total: $19.30

17
Storage System
The storage system is the last step in the operation flow chart of the machine as it takes effect
at the end of the sphere harvesting process. The system is responsible for storing all collected
balls and depositing them into the basket at
the end of the test run. The storage system
was designed to operate successfully with a
load of either 25 tennis or lacrosse balls.
Tennis balls were the largest type of ball that
the R.O.B.O.D may have had to pick up, while
lacrosse balls were the heaviest. Therefore,
the R.O.B.O.D would also have no problems
picking up golf balls. The storage system is
located at the backend of the R.O.B.O.D and
consisted of three basic components: the
storage container, rotating door and scissor
lift. Figure 17 to the left displays a solid model
representation of the storage system and all
its parts. The final product’s storage system
matched this exactly. The grey base at the
bottom is actually the movement system’s
frame, but is displayed as a reference for the
lead screw.
The storage container’s design changed very much since the beginning of the school year.
Originally, the container was designed as a hollowed out square containing no features except
for slanted inward sides. Additionally, team one was considering aluminum as the material and
welding to join each side together. As the other components used within the R.O.B.O.D
developed and problems were identified and mitigated, the storage container slowly took the
form of the final product. The final storage container consisted of four separate parts joined
together by finger joints. These parts were the storage base, front and two sides. The base
possessed a false floor at a five degree angle to allow the balls to roll out naturally. The final
storage container was 11 inches long, 9 inches wide and 5.7 inches tall normal to the sloped
floor. The wall thicknesses were a quarter inch. The container was shaped rectangularly.
Additionally, rather than using aluminum as the container’s material, the team used PLA plastic
by 3D printing each part instead. By using PLA plastic, the team was able to maintain the
storage container’s strength while greatly reducing its weight. One cutout on the left side and
front side parts existed in order to place the sorting base and ramp. Because the door counter
weight and sorter base and ramp took up space within the storage container, the exact value
Figure 17: The storage container, door and scissor
lift make up the storage system.

18
for usable volume was unknown. However, by experimentation, the storage container did have
enough volume to store 25 tennis balls even with the sorter base and ramp.
The door component consisted of a door, counter weight, door arm, servo motor, shaft and
two bearings, collars and sleeves. It held the balls within the storage container until the
appropriate time when the machine was in position to deposit. The door arm served as a latch
to keep the door closed until that time and was the only powered part in the door component.
It would rotate down with the servo motor spindle allowing the door to open about the shaft. It
was controlled by a remote controller
programmed through an Arduino. The servo
motor was attached to the bottom of the
storage base by a small 3D printed attachment
piece. The counter weight was also 3D printed
and attached to the interior, top of the door. It
was filled with nuts to add a moment to the
door allowing the door to rotate open by just
the force of one golf ball. The door was 5.7
inches tall, 7.3 inches wide and a quarter inch
thick. It was 3D printed using ABS plastic. More
so, the top part of the door was circular and
contained a quarter inch through hole for the
shaft to go through. The two collars went on the
shaft, followed by the sleeves. The remainder of
the shaft went through the bearings and
container sides. The shaft was 9 inches long and
a quarter inch in diameter. Figure 18 displays a
visual of the door component.
Finally, the most complex component associated with the
storage system was the scissor lift. It contained a large
amount of hardware and required a high torque input to
raise. The scissor lift was designed keeping in mind that
each demonstration run was only two minutes long and
that the max load that the scissor lift may be required to
raise was 12 pounds. Because of these factors, a lead
screw with a wide diameter and coarse threading and a
motor with a high torque were chosen to drive the scissor
lift’s motion. The lead screw possessed a 3/8 inch
diameter and was able to move ½ inch per revolution. In
Figure 18: The door component released the
balls into the basket at the appropriate time.
Figure 19: Lead Screw to Drive Shaft
Attachment

19
order to join the lead screw and drive rod together, a flange and nut specific to the lead screw
were purchased and a custom designed piece was 3D printed. The 3D printed piece connected
with the lead screw flange by bolts and nuts and to the drive rod by a through hole and two
collars. The lead screw flange possessed internal threads and screwed onto the lead screw nut’s
external threads. Because the lead screw nut also possessed internal threads, those were used
to screw onto the lead screw. This assembly can be seen in Figure 19 on Page 18.
The scissor lift needed to raise the bottom of the storage container up to the height of the final
receptacle. This was nine inches. For this reason, eight links of 9.5 inches long and 13/16 inches
wide were used to give the scissor lift enough vertical motion to complete the task, while also
keeping the loaded storage container stable above. When the scissor lift was compressed at
about a seven degree angle, the total height of the lift was approximately 3.25 inches. When it
was expanded, the height reached ten inches. Steel cross shafts were added to reduce
horizontal sway while the lift was in motion. These shafts helped keep the system stable. Four
of these shafts were 3/16 inches in diameter, while the drive shaft was a quarter inch to
withstand the high torque of the lead screw and motor. The scissor arms were held firmly in
place using axle collars. Where shafts were not used to connect the scissor arms together, a
combination of shoulder bolts, washers and nuts were used. L-bars were used at the top and
bottom of the scissor lift to keep one end of links fixed and the other movable. They were
attached to the storage and movement components through the use of hot glue and bolts,
respectively.
All the components, other than the collars and fasteners, had to be manufactured in the
machine shop. A lot of time was taken for the team members to learn how to use the lathe, drill
press, milling machine, sander, and band saw. The SolidWorks model of the scissor lift can be
viewed below.
Figure 20: The complete scissor lift design with all its
parts.

20
Movement System
As mentioned in the design approach of this text, the Team planned to utilize tank treads to
move the device around. The image below depicts the intricate 3D movement system model
that the Team created. It consisted of the framework that provides structure to its components,
the drive axles that translate the torque from the motor into the rotational motion of the
sprockets and the idler axles that allow for free rotation of the sprockets not connected to the
drivetrain. In addition, it would also consist of the wheels that would distribute the device’s
weight, and the treads that provide the traction against the ground and the motors that would
convert electrical energy into mechanical energy.
The mentioned tread system would run along the four set of components and would sit into
place by meshing with the teeth of the sprockets. Essentially, the treads would look like the
image below. This idea, Figure 22 found on rctankcombat.com involves the use of a key
component, bike chains with the pins removed. Essentially, a bolt would connect from the hole
in the first bike chain, run through the piece of rubber hose, through the hole to the next bike
chain, and would finish with a nut cap on the end to hold all components in place.
Figure 21: The initial movement
system design.
Figure 22: A tread design using
bike chains and sprockets.

21
The movement system was ultimately one of the biggest challenges for the Team. At about four
weeks left of the semester, the Team opted to discontinue any progress with the Treads. The
major reason behind this decision was that the days left until demonstration day was very
limited and building the treads were taking
too long. For example, it would take a
ridiculous amount of time and effort just to
remove every single pin out of the bike chain.
Another reason why the treads were
discontinued was that the design of the
treads greatly influenced, and thus stalled the
construction of the scissor jacks, another
major part of the device. Thus, the team
quickly devised a new movement strategy
and opted for two 2” diameter front wheels
and two rear golf ball castors that would help
the device easily make turns.
Unfortunately, after all of the components were added to the device, the system became
relatively heavy. The casing of the golf ball castors began to enclose the golf ball too much—at
a point in which there was no longer enough golf ball exposed surface area to make contact
with the ground. As a result, the team began designing new custom made, but larger and solid
3D printed casters that would solve the limited surface area problem created by the golf balls.
The second type of which can be seen in Figure 24 to the bottom right.
Once returning back to the testing field, the system
still did not move. The casters still sank into the turf,
so the team’s next action was to create a rectangular
sled that would have even more surface area and
support the system’s weight better. This design was
very similar to the model seen in Figure 25 on the
next page, except the front portion was not curved
upwards. At this point, the device could now move,
but at an extremely slow rate. Although the fact that
the device was now moving was great progress, the
device still had room for improvement so the team
continued to attempt to make the device better. This
Figure 23: A ball caster containing a ping pong
ball. Team one tried scaled it up for a golf ball.
Figure 24: The caster-sled hybrid piece
created by the team.

22
led to purchasing two inch rotational wheel casters
from Home Depot as shown in the image to the left.
Although the system could now move much faster than
the rectangular sled, the wheel casters had their own
problems. When stopping the machine to back up, the
casters would sink into the turf and get stuck. The
motors used within the movement system to drive the
machine did not possess enough torque to overcome
this. Coming to the conclusion that it was best to move
slowly, rather than to not move at all, team one went
back to rectangular sled concept and made slight
modifications. These involved curving the front of the
sled upwards at a 30 degree angle to avoid it from
digging into the turf. The thickness of the sled was also
reduced from a half inch to a quarter inch. MonoKote was then attached to the bottom of the
sled to give it a slick bottom surface. The final sled design is shown in below.
In addition, the team bought new “Shootout Speedtreads” wheels that were larger in diameter
and in width and thus had more surface area in contact with the ground. This directly
correlated to the new wheels having more traction and allowing the machine to move better on
the turf. These final changes to the movement system enabled the device to move like a charm.
Figure 25: The final sled design by team one.
Figure 26: Two inch wheel caster
purchased from Home Depot.

23
Controls System
The controls sub-system of the design solution consists of the hardware and software that
allows the team member to manually control the machine’s operations. The processes that
must be controlled manually include the individual movement of each wheel, the designation of
the objective ball, the raising and lowering of the scissor lift, the opening and closing of the
door at the back of the storage compartment, and the rotation of the feeder component. The
processing and movement done by the sorter
component are dictated by the content of the
code being processed by the Arduino Uno
software. Three additional circuit boards each
serving an individual function are stacked on
top of the Arduino board resulting in a single
multi-layered module that serves as an
interface for the signals sent between all the
electronic components within the machine. This
is seen in Figure 27 to the left.
The Arduino layer draws current from a power source and then distributes the signal to the
various hardware connected to the digital and analog pins on the board according to the
uploaded code and manual input of the operator.
One such function of this software is to send a signal to the servo motor connected to the
sorter resulting in the ball in the sorter to be stored or rejected based on the feedback signals
from the optical sensor and the FSR. The software is also designed to direct a signal to the
motors driving the treads based on the Bluetooth signal received from the PlayStation
controller.
Figure 27: The Arduino Uno multilayered module.
Figure 28: The Aurduino Uno purchased for the controls.

24
A proto-shield is stacked on top of the Arduino board. This layer is where the external electrical
components such as the optical sensor and the FSR are directly wired to provide power to these
components and to receive the necessary feedback from them. This is shown in the figure
below.
The next layer is the motor shield. All six of the machines motors are directly wired to this
board in order to receive a current of up to two amps based on the signals received from the
Bluetooth controller. The motors include one servo motor for the sorter, one servo motor for
the storage door, one DC motor for each tread, one DC motor for the feeder and one DC motor
for raising the storage compartment. This is seen in Figure 30.
The final layer is the Bluetooth shield where the wireless Bluetooth receiver is directly
connected. This component receives signals from the PlayStation controller based on the
manual input from the user. The circuit board can also handle a direct wire connection from the
PlayStation controller in case of interference issues with the wireless connection. This is seen in
Figure 31 on Page 25.
Figure 29: The Arduino Uno’s proto-shield module used in the
controls.
Figure 30: The Arduino Uno’s motor shield used in the controls.

25
The power source chosen is a rechargeable 12V
Lithium-ion battery which also connects directly to
the multi-layer module. This particular battery
provides a 20,000mAh supply current and a 1-2A
output current. This battery, along with the control
module and the motors for each tread, will be
stored underneath the storage component within
the base of the device.
The code uploaded to the Arduino carries out its
operations in a loop-based fashion. The loop is
prefaced by a startup function that runs once
when the PS3 controller is connected to the module either directly or via Bluetooth. The main
loop then consists of four separate functions each designed to control an individual sub-system.
The movement control function is designed to receive an analog signal from the left stick on the
PS3 controller. Pushing the stick relatively harder will translate to higher analog values resulting
in an increased voltage supplied to the motors, therefore increasing the speed of the motor.
The feeder control function analyzes the digital signals sent by the “R1” and “L1” buttons on the
controller. Tapping “R1” once will rotate the feeder forward while tapping it again will stop the
feeder motion. Tapping “L1” rotates the feeder in the opposite direction. This was integrated
into the code in case a ball gets stuck in the feeder/sorter interface. The sorter control function
receives the digital signal from pressing the “Square” button and outputs a signal to one of
three LED lights each time it is pressed. Each light corresponds to a single ball type and the
operator will press the “Square” button until the light representing the desired ball is
illuminated. The storage control function responds to the digital signal produced by pressing
the “Circle” button. Pressing the button once causes the motor driving the scissor jacks to
rotate. One press raises the scissor jacks, a second press stops the motor, a third press lowers
the scissor lift and a fourth press stops the motor again. Pressing the button again after this will
start the process over again.
Figure 31: The Bluetooth shield used in the
controls.

26
Development of Preliminary Analytical Models
When designing the entire ball harvesting machine, analytical work had to be done in order to
know if the machine would perform ideally. Each system required analytical work but the two
components that required the most were the feeder and storage systems. For the feeder, team
took into consideration the maximum height of the feeder, necessary diameter of the
pulleys/sprockets, number of necessary fins, rate at which the balls should enter the feeder and
the angular speed of the motor required. With the use of an excel spreadsheet team one was
able to incorporate equations to the various outputs of results given a specific constraint or
input. The table below displays some of the initial feeder calculations.
With the design constraint at hand, the team’s mechanism was restricted to 11 inches in height.
The team made further reductions and came to the conclusion that the feeder could not exceed
eight inches tall due a maximum three inches of clearance height required from the ground.
The largest ball is approximated to be 2.7 inches in diameter so the team made a rough
estimate of 3 inches incorporating spacing for the ball to move within the feeder. The rate at
which the balls entered the feeder was a very important factor as it affects the amount of balls
that can be stored and deposited within the given time frame. The ideal rate that the team
Figure 32: Initial calculations on the feeder. The feeder changed significantly
over the weeks leading up to demonstration day so these calculations no
longer apply.

27
desired the balls to enter the feeder is 2 seconds per ball. The maximum time frame per ball the
team was willing to allow was a rate of 4 seconds per ball. As can see in Figure 32 and Figure 33,
as the rate at which the ball enters the feeder increases, so does the angular speed of the
motor required to carry out the task.
Figure 33: Displays more initial calculations on the feeder using different variables.
The number of fins attached to the belt of the feeder directly affected the output angular
velocity of the motor. As seen in Figure 32 and Figure 33 if the number of external fins is
increased from 3 to 4 then less angular speed is required from the motor to rotate the feeder.
However, if the number of fins is drastically reduced from 4 to 2 and the feeder is required to
intake balls every 2 seconds, then the angular speed necessary is increased from 21.2 rev/min
to 43.6 rev/min. The team, through multiple trial and errors, experimented with varying input
variables to receive the ideal outputs values for the feeder.
The storage system underwent many preliminary calculations early in the fall 2015 and spring
2016 semester. In the fall 2015 semester, calculations pertained to the storage container used
in the system. The goal was to be able to hold 25 tennis or lacrosse balls during demonstration.
As such, the internal volume needed and max weight that the system might see were
calculated. The volume of 25 tennis balls was calculated to be 191 inches squared. As such, the

28
very first container was designed to have an internal volume of 250 inches squared to
compensate for the wasted space between each ball. Because lacrosse balls were the heaviest
type of ball the machine might have had to pick up, the system needed to be capable of
supporting the weight of 25 such balls. This weight added up to about 8.25 pounds. Assuming
that the sorter mechanism and storage container weighed a total of five pounds, the team
designed the scissor lift to be able to raise 13 pounds. Preliminary calculations using basic
trigonometry were done for the scissor lift to design the length of the scissor arms and the slots
of the L-bars. The angle of the scissor lift was designed at seven degrees when compressed and
35 degrees when expanded. The scissor arms were designed to be 9.5 inches long to keep the
storage container stable under full load, regardless if the lift was compressed or expanded.
Final calculations included the torque needed to drive the lead screw. The value was
determined based on the weight being lifted, coefficient of friction between the lead screw and
nut, diameter and thread density of the lead screw. This yielded a required torque input of at
least 0.820 pound-inch.

29
Advanced Modeling & System Simulation
When designing the R.O.B.O.D, team one made heavy use of computer aided design,
particularly with the programs SolidWorks and AutoCAD. AutoCAD was not used nearly as much
as SolidWorks however. AutoCAD was primarily used in the fall 2015 semester when the team
was still developing preliminary concepts and generating ideas. AutoCAD was useful in creating
2-dimensional drawing of parts to illustrate ideas. As ideas and concepts began to develop, the
team moved on to SolidWorks as their primary CAD program. This translation occurred just
before the end of last semester. SolidWorks was extremely useful in creating 3-dimensional
parts and assemblies to give the team a visual representation of the machine and its
components. Because of this, it allowed the team to foresee potential problems especially
those regarding the combinations of components. For example, from the machine’s assembly
model, the team learned that the feeder was not
nearly tall enough at its current state. The plows
carrying the balls were not able to reach the
sorting mechanism mounted at the top of the
storage. As a result, the team mitigated this
problem and designed the feeder to the
appropriate height. Other issues that were
mitigated involved cutouts for motors and the
lead screw. Bolt holes for mounting were also
created to assemble each component. Because
of the ability to mitigate potential problems, the
team held to an important rule. Almost every
part was required to be 3-D modeled and
installed in the machine assembly on SolidWorks
prior to being manufactured. If errors were
discovered after parts were manufactured, it
would have created major issues for the team
and been very costly to address. Figure 34 to the
left displays the 3D modeled assembly of the
R.O.B.O.D.
By modeling parts using both AutoCAD and SolidWorks, the team had the ability to save the
files as .STL and 3D print many of the parts. Much of the R.O.B.O.D is made up of 3D prints. The
entire storage container and sorter mechanism were 3D printed using PLA and ABS plastics,
respectively. The feeder ramp, frames, plows and gears were also 3D printed. For the
movement system, the frame parts and sled were all 3D printed. All of this would not have
Figure 34: The feeder, sorter, storage and
movement systems are shown in the figure
above. The scissor lift is expanded half way.

30
been possible without the usage of CAD. The team would have had to have used a different
method.
Another benefit of using SolidWorks to 3D model the entire machine assembly was the ability
to simulate the moving parts of the machine. These moving parts included the feeder E-chain
and sprocket mechanism, sorter claw, scissor lift, door and latch mechanisms and movement
wheels. Using SolidWorks to simulate allowed team one to discover a problem with the sorter
claw and pallet. The sorter claw was not able to rotate fully as there was inference with the
sorter pallet. As a result, team one adjusted the design of the claw and mitigated this potential
problem. Due to simulation, team one had a good idea of how the machine was going to
function leading up to demonstration day.

31
Testing & Experimentation
Team one’s approach towards testing and experimentation was to integrate each into the
progression of the design and manufacturing processes. In order to achieve this without
wasting time and material, it was imperative that the team was highly confident in any
particular design before working with physical material. Therefore, the early stages of testing
relied heavily on the virtual modeling and simulation of each system within the design of the
R.O.B.O.D. As previously discussed, the team primarily used SolidWorks to virtually produce
parts and assemble each separate system in order to gain a three-dimensional representation
of how each part would have to combined in order to carry out the system’s intended function.
Each system was then virtually assembled with each other in order to render a representation
of the R.O.B.O.D. in its entirety. This was used to determine if each system would work without
interfering with the rest. Once a suitable model had been obtained with the ability to function
within the software, the team was confident enough to begin ordering materials for
prototyping.
Most of the physical experiments occurred after a prototype had been built. Some prototypes
were able to be built long before others; therefore each prototype had its own functionality
tested before its functionality relative to the entire R.O.B.O.D. For example, the sorting system
was the first prototype completed and was subsequently tested using a golf, tennis and lacrosse
ball. At first, the sorter was not correctly identifying each ball, so the code that was written to
describe this function had to be edited until the software was consistently outputting the
correct command to the sorting claw. A prototype for the feeder was completed relatively early
on as well. This system initially failed to operate properly due to the excessive weight of the
pulley stocks originally chosen to drive the vertical conveyer belt-like operation. Also, the team
found that it would be difficult to attach rigid plows to a traditional rubber belt that would
deform while passing around the circumference of the pulley stocks. Therefore, the team
redesigned the feeder to utilize chain links that would be driven by custom-designed 3D-printed
sprockets. This new design was then assembled and tested and proved to work properly. The
chain links would stay rigid while passing over the sprockets, allowing for a stable connection
between the chain and the plows. Also, the plastic sprockets turned out to be much lighter than
the aluminum pulley stocks and could therefore be driven easily by the feeder’s motor.
Alternatively, the movement system required the most repeated testing. Originally, the idea
was to use a tread-based design similar to that of a military tank. However, building the treads
out of bike chains and rubber tubing as planned turned out to require extensive amounts of
labor only to yield a result with a low chance of performing well on the turf that the R.O.B.O.D.
would have to move over on test day. The team then switched to a design utilizing four wheels,
of which the two in the front portion of the machine would be directly motor-driven. However,

32
testing revealed that the rear wheels were dragging instead of rotating when the R.O.B.O.D.
attempted to turn. To solve this issue, the rear wheels were replaced with ball casters to allow
more freedom of movement. Once the team had the opportunity to test the movement on turf,
it became evident that the casters would sink into the soft turf field and completely cease all
movement. Finally, the team came up with the final design which utilized a sled with high
surface area mounted on the rear end of the R.O.B.O.D. in order to allow it to slide over the
turf. In order to reduce the kinetic friction induced by moving on the turf, the sled was also
coated with MonoKote material, which is commonly used on the aerospace engineer’s
airplanes to reduce drag.
The scissor lift also required much testing to ensure that it could lift the load of 25 lacrosse balls
on demonstration day. To test the lift, two different lead screws and motors were tried
together for four different combinations. One lead screw was 5/16 inches in diameter and
possessed fine threading. The other lead screw was 3/8 inches in diameter and possessed very
coarse threading for more displacement per rotation. The motors were both the same size but
contained different specs. The first motor had a high rpm, but lower torque. The second motor
had a low rpm, but very high torque. When testing each lead screw and motor combination, the
best results came from the 3/8” lead screw with coarse threading and the high torque, but low
rpm motor. This was because the high torque motor was able to lift loads excelling 25 lacrosse
balls, while the coarse threaded lead screw with a 3/8 inch diameter compensated for the
motor’s low rpm. Other combinations failed to achieve this balance, failing either by insufficient
torque or very slow raising speed.
In the week leading up to demonstration day, final tests were conducted on the feeder and
movement systems. The team tested to determine the ideal mounting height of the feeder so it
would be able to pass over the turf without slowing down movement, but also be low enough
to allow the balls to easily transfer from the turf field to the feeder’s ramp. When tests revealed
that the feeder was located too low to the ground causing the ramp to dig into the turf, spacers
were inserted at the mounting points between the feeder and the movement frame to raise the
entire system to an adequate height. This situationally-based method of experimentation
described above allowed the team to work continuously until the desired outcome was
obtained.

33
Production & Manufacturing
Most of the R.O.B.O.D. is composed of 3D-printed material and irreducible components
purchased online. Therefore, most of the production and manufacturing was completed
through the 3D-printing process itself. The members of team one did, however, employ
traditional machining methods when it came to manufacturing the scissor lift as well as the
various shafts and motor couplers. The scissor lift required four L-brackets to mount it to the
movement frame and the storage system. Additionally, the lift is composed of eight filleted
links and five shafts, four three-sixteenth-inch shafts and one quarter-inch shaft. This material
was purchased from Home Depot and McMaster-Carr as the student machine shop did not
have the stock material required by the design. However, the material still required fabrication
in order to fit the design specifications. The brackets were first cut down to a length of eleven
inches. Each bracket then needed a slot machined into it using a milling machine to allow for a
shaft to slide back and forth. Three holes were also added using a drill to allow a bolt to pass
through them for mounting. The interior of the slots were made to be as smooth as possible
with the use of a file to reduce friction caused by the movement of the shaft. The scissor links
were also cut down to their proper length of nine and a half inches and width of 13/16 inches
from one initial piece of material. To make these cuts, the band saw and mill were both utilized.
Each link required three holes to be drilled through them, one at each end and one in the
middle. It was essential that each link was machined to be identical to each other to allow for
proper movement of the scissor jacks. The corners of the links were rounded using a belt
sander. The shafts were cut down to a length of eight inches to reach across the width of the
scissor jacks and were then filleted at the ends also with the use of a belt sander.
Four couplers also had to be machined in order to connect the two movement motors with the
drive shafts, the feeder motor to the gear driving the feeding system and the lead screw used in
the scissor lift to the motor’s shaft. This was done by milling out a cylindrical hole through the
interior of carbon steel rods to fit the diameters of the motor shafts on one end. A similar hole
was milled out on the other end with a different diameter to fit the driving shafts of the
movement and feeder systems and lead screw of the scissor lift. Through-holes were drilled
into the couplers sides and threaded to implement set screws in order to marry the rotation of
the motor shaft to the rotation of the drive shafts or lead screw. These driving shafts as well as
the shafts that allowed the feeder system to rotate also had to be machined by the team. The
driving shafts were cut down to a short length of one inch in order to position the wheels just
outside the movement frame while the feeder shafts were cut down to a length of five inches.
Manufacturing components based on completing a functional sub-system made things simpler.
Once each sub-system had been manufactured and tested, they simply had to be connected to
each other in order to complete the assembly process. The final assembly of the R.O.B.O.D
proved to carry out all its intended functions without any internal interference.

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Demonstration & Performance
When equipped with a fully charged battery, the machine was able to swiftly move around the
competition area on demonstration day leaving ample time to collect, store and deposit at least
half the number of a particular type of ball present on the field. In this respect, the R.O.B.O.D.
was successful in completing all the required tasks presented in the problem statement of this
project. Namely, the R.O.B.O.D. is a compact machine which operates without producing any
harmful emissions, without the need of direct human intervention to perform any of its
functions and without leaving any physical components on the field after the task had been
completed. The machine has the ability to move and turn at a rate which allows the user to
precisely position the device at the desired location and orientation. The feeding chains were
able to rotate, stop and reverse direction consistently without failure. While the machine was
fully able to distinguish between each ball for the purpose of either storing or rejecting them
according to their weight and size, this function turned out to be unnecessary during the
second test run. This was because the balls within the test area were spaced apart at a distance
that allowed the user to pick up one at a time without also accidentally picking up an adjacent,
undesired ball. While using the sorter and allowing it the necessary operating time, the
machine was able to harvest, store and deposit six tennis balls, while also accounting for a
malfunction that will be described shortly. However, once the sorter was removed, there was
no longer any need to allow for this operation time and the R.O.B.O.D. was able to continuously
harvest balls immediately after coming into contact with them. During the test run without the
sorter, the machine successfully deposited twelve golf balls into the basket. The only function
that required the team to be conscious of the time across all test runs was raising the storage
container using the scissor lift. This was because this function required a high amount of torque
to carry out, so the motor chosen needed a high gear ratio in order to be able to output that
torque. High gear ratios grant the capability for higher torque output, but at the cost of a lower
output rotational velocity.
Despite all the success achieved by the R.O.B.O.D. on demonstration day, there remained to be
failures within the design and performance of the machine that prevented the absolute optimal
outcome. For example, a malfunction with the controls system was a major factor in hindering
the performance of the mechanism during the first test run. After the machine had harvested,
sorted and stored a total of six tennis balls, the connection between the PS3 controller and the
Bluetooth shield of the Arduino was lost. This required the two power sources be turned off
and then turned on again in order to reset the connection. This took between thirty and forty-
five seconds to complete and therefore limited the amount of balls the team could successfully
deposit. While it is not known exactly what caused this malfunction, the team believes it is due
to the nature of the current distribution carried out by the Arduino hardware. It would make
sense that if the motors driving the movement system or potentially any of the other motors

35
within the machine were not consistently receiving the required amount of current that this
would require the controller hardware and/or software to cease to function. One thing is for
certain, that the current design for the controls system draws too much power from the power
source. Any battery the team decided to use was being discharged at an alarming rate.
Additionally, one of the two motors driving the movement system seemed to be consistently
receiving an insufficient current as it was not outputting as much torque as the other drive
motor. An additional battery was introduced as an alternate power source used to power the
motor shield directly instead of passing current through the entire control module.
Another factor hindering the performance of the design was the interaction between the
machine and the turf field. Since most tests concerning the movement of the machine were
conducted on a hard surface, it was difficult to determine if that particular design would also
correctly operate on a turf field. Once the team was granted the opportunity to test the
machine on a turf field, it was revealed that the soft nature of the turf material caused the
machine to sink to a lower position. This caused major movement problems by causing greater
resistance against the rotation of the wheels and the displacement of the sled and by causing a
direct interference between the front of the feeder and the turf. When the machine sunk to a
lower position, the front of the ramp on the feeder would dig into the turf and cause the
R.O.B.O.D. to cease all forward motion. This particular portion of the problem was solved by
raising the feeder to a greater height. This had to be tested multiple times though, as raising
the feeder too much would make it difficult for balls to easily roll onto the ramp rather than
being pushed by it. This particular failure was not catastrophic in terms of the overall feasibility
of the design though, while the issue with connection remains to be a danger to feasibility. This
too can be solved though, potentially with the integration of a more reliable power source or by
redesigning the controls system. Although, complete mitigation of this risk can only be
accomplished through further testing, regardless of proposed solutions. Lastly, a potential area
for failure exists within the scissor lift. This should only be stated because this component was
completely manufactured by the team from scratch without any member having previous
experience involving manufacturing this type of mechanism. The scissor lift performed its
required function as long as the team has been using the R.O.B.O.D., but it has been observed
to occasionally raise and lower unevenly and rarely even get stuck in a particular position for a
short time. These imperfections in the design did not stop the overall machine from
successfully completing its task; however, they definitely present a potential for failure down
the road under continuous use.

36
Design Assessment
Requirement Achievements
The objective of this project was to develop a variety sphere harvesting machine given certain
constraints. The machine needed to be capable of gathering, sorting and depositing the types of
balls into a basket. More so, the machine needed to be able to move well on the Carrier Dome’s
turf field. The team met and exceeded the requirements of the project. The R.O.B.O.D was able
to pick up and deposit 6 tennis balls on the first run and 12 golf balls on the second. Those were
the highest amount of balls picked up and deposited compared to any other team. The team
was able to achieve this within the two minute time limit. The team also nearly met the size
constraints of 17” x 11” x 9”. Overall, team one achieved their goal set forth from the beginning
of the 2015-2016 school year.
Product Enhancements & Life Cycle Analysis
Overall the Robot’s design has met the team’s basic standards of expectations. However, in the
development and future improvements of its functionality, the team suggests a few product
enhancements. As seen prior to testing, the robot’s full functionality draws a large amount of
power from to operate the motors of the feeder, scissor lift and movement. This drawback will
have detrimental effects on the robot’s life cycle as the 9V batteries will have been drained
completely within a few test run. Also the large amount of power being drawn causes the robot
to operate in short burst runs unless connected directly to a nearby power outlet. Once
operating wirelessly and on 9V batteries, the probability of the robot shutting down is high. The
team suggests obtaining and attaching a power supply large enough to power the various
motors including the Arduino. Such an upgrade requires a regulator for the Arduino as the
device is limited to how much current can be taken in. If the Arduino power threshold is
exceeded, the circuit will eventually fry and the control for the entire mechanism will have been
lost.
Secondly, friction has been one of the big focuses on improving the robot’s design. Initially
harvesting lacrosse balls had been impossible due to its material surface friction and the friction
caused when coming in contact with the plows. To overcome this obstacle for test day, the
team had invested in WD-40 lubricating the plows, the ramp, the scissor jacks, and even the
sprockets themselves. The improvement had been seen instantaneously as all the various balls
on the field were picked up with ease and with a great amount of time efficiency. However,
WD-40 is a temporary mitigation process as it will wear off within a limited frame. Developing a
self-lubricating process will enhance the robot’s operational capability.
Thirdly, the fin attachments on the feeder E-chain need to be secured in a stronger way. The
team used hot glue to temporarily attach each fin to the feeder. Hot glue can only last for long

37
however. During the team’s first test run on demonstration day, one of these fins actually fell
off of the feeder. Thankfully, the other two fins stayed on for the remainder of that day. On
poster day however, the negative of using hot glue finally revealed itself as the remaining two
fins finally fell off. In the future the fins should be attached using a stronger adhesive or by
fasteners.
Lastly, improving the movement system ability to perform well on any turf is another highly
suggested area for product improvement. The current wheel design designed for short term
use has excelled expectations, but has developed concerns for future usage. Being able to
obtain methods such as tank threads to maneuver any turf and steer smoothly in any direction
will take ball harvester design to greater heights.

38
Project Management Timeline
Since the time team one formed early first semester, each member was designated a particular
system of the machine to research and design. These were the feeder, sorter, storage,
movement and controls systems. However, as time passed, each sub-system became more
interconnected and therefore the efforts from each team member grew towards becoming one
cohesive effort from the team as a whole. To make sure the team stayed on track with each
system, a Gantt chart was created early in the fall semester. The final Gantt chart can be seen
within the Appendix section of the report. The Gantt chart was split up into three main sections
with one containing several subsections. These three sections were: Design and Build Phase, Bill
of Materials Phase and Assignments and Papers Phase. Each is exactly as the name says and
contained tasks related to such. The design and build section contained tasks related to the
actual machine. The bill of materials section delegated tasks to maintain the team’s budget.
Lastly, the papers phase involved all written assignments throughout the spring 2016 semester.
Additionally, it included the gate presentations, design reviews, elevator pitch, poster session
and demonstration day.
The design and build phase was the most important section of the three as it was important for
the team to stay on task to end up with a successful and final built machine by demonstration
day. It was broken up into subsections, one for each system or component of the machine and
one for the entire machine itself. The tasks that followed were related to each system. For
example, “machine scissor arms” was listed under the storage system.
While the Gantt chart did help the team stay on track, it was also unreliable and difficult to
follow accurately. This is because things always changed, whether it was a busy week for a
team member with exams or the design of a system or complications to creating a part. If one
task was not completed on time, it often affected other tasks since many were dependent upon
each other. For instance, the task of testing the feeder-sorter combination to make sure the
balls reached the optimum height was delayed because the movement system was not
completely built yet. Also, the team moved away from a treads based movement system the
week after spring break. This change made many of the tasks listed on the Gantt chart at the
time irrelevant. Even though the Gantt chart was not perfect, it did assist the team in reaching
their goal of having a successful machine by demonstration day.

39
Economic Analysis
Cost Considerations
The budget for the team’s project was $250.00 that was provided by the College of Engineering.
Any additional needed money had to come out of the team’s own capital. Team one decided
that they would pay for the entire project out of pocket so that they could claim ownership of
all the parts used in the project after completion. However, based on the guidelines, the team
wanted to stick to spending $250.00 or under if possible. With this in mind the team started
researching ways to save money where possible so that more money could be spent on better
components that will lead to a better performing machine. The full budget spreadsheet can be
seen in the appendix of this report.
One of the biggest places the team saved money was for the material used on the structure of
each of the machine’s components. 3D printing is a simple, quick and effective way of
prototyping and manufacturing final parts. As such, team one used it to construct most of the
machine’s structure for this project. There are currently two placed on the Syracuse campus to
3D print: the engineering machine shop and SU MakerSpace. At the MakerSpace, students are
allowed to print up to 150 grams of ABS plastic per week while at the machine shop any printed
ABS or PLA plastic is charged to the College of Engineering at the end of the semester. By
utilizing both places wisely, the entire machine’s structure could be fabricated for free. There
are limitations associated with 3D printing, such as printing accuracy and printing time. There
are also constraints, such as the amount of 3D printers available at both the MakerSpace and
machine shop. There is no guarantee that a 3D printer will be available at any given time.
Ultimately, the biggest limitation of 3D printing is the size print that a 3D printer is capable of
producing. Some parts of the team’s project were so big that only two 3D printers on campus
were capable of producing the parts. One of which is currently under service.
Another method the team used to save money was by acquiring equipment and materials from
companies interested in the project. One such company was Igus, a manufacturer of various
mechanical hardware centered around plastics. Igus has a program called “Young Engineers’
Support Program”, (Y.E.S), which allows engineering students to foster their mechanical
engineering concepts through no cost. The team applied to Igus’ program and was awarded
three feet of its E2 micro energy chain, a part that would have cost the team about $40.
Another company the team spoke to was JJ Associates, who happened to have excess
aluminum toothed pulleys and corresponding conveyor belts. After a brief conversation with a
representative, the company even cut and assembled the conveyor belt to the proper size
required and shipped it with the aluminum pulleys to the team at no cost.

40
The last way the team saved money was by sourcing parts from various connections that the
individual team members have with the community. All the bike parts used in the project such
as the sprockets and bike chains were repurposed throwaway parts from one of the team
members’ workplace. The optical sensor, wiring, resistors and motors were all from a members’
home shop.
These three tactics to acquire free material were extremely beneficial to the team’s progress as
it allowed for verification of ideas that had only been drawn up on paper. Validating concepts
before the final manufacturing of the machine was a key component to the team’s success as
adjustments can be made relatively easily as opposed to if the team built the entire machine
first hand.
The rest of the parts to the machine had to be bought with the most expensive being the
motors and control modules. The Arduino and the extra boards that mount directly to it had to
be purchased early on in the project’s development as none of the team members knew
anything about programming in the Arduino language. Because of this, a substantial amount of
the budget was used quickly and the rest of the design needed to compensate for the lack of
funds. The team members did their best to find the cheapest parts available and a total budget
of $650 was attained.
Sales and Profit Consideration
If this device were to be manufactured and sold, the total cost to build it would be decreased
through bulk ordering and mass production for majority of the parts. The only portions of the
device that are custom made are the 3D-printed parts, but for the final version those parts
would most likely be switched to molded plastics to produce them more quickly and accurately
without compromising their strength and durability. If these revisions are made, the expected
price to manufacture the device would drop by approximately $200, but the overall markup for
retail would make it commercially available for about $800.
The target market for this product would be to sport centers that want to have the option of
remaining comfortable indoors while retrieving sports balls from places such as a golf range.
This device also has the capability of going places no man has ever gone before by being small
and portable so it can reach awkward spots. With the implementation of this device, the
company can also save money as the device incurs a one-time cost of the initial purchase plus
any minor repairs that may need to be done. If this device were to replace an employee who
has a nominal pay rate of $15/hr, the return on the initial investment for this device would be
after 54 hours of work. Unlike their human counterparts, this device can work tirelessly and up
until it needs to be recharged, making it much more efficient than the human worker.

41
Society and Environmental impacts
This device is aimed at directly replacing exhaustive human labor by allowing employees to
perform their tasks indoors comfortably. As the device evolves through different models in the
future it could potentially replace the worker by becoming completely autonomous, able to
map out its entire course so that it would be able to patrol and retrieve balls and other objects
when necessary and in the most efficient manner. One robot working tirelessly between
charges could save a business a lot of money compared to if they had a human performing
those tasks which makes the device more attractive than its human counterpart. As such, it
could potentially replace all human jobs that are associated with retrieving small objects.
Further iterations of this device could increase its size so that it would be capable of retrieving
larger objects like trashcans and other large objects. This would impact the working society by
allowing these devices to perform the more difficult and potentially dangerous tasks.
The societal impact of the evolution of this device, as well as other remotely operated devices,
can put a lot of employees out of jobs by being more efficient, accurate and tireless. This is a
huge problem for the growth of our society, as the unemployment rate would rise as
technology advances and becomes cheaper. In order to ensure that the population has the
capital to support themselves and run a healthy economy, the transition between human
power and robotic power needs to be thought out in a more succinct way. That being said,
these devices are expendable and can be used to complete difficult and hazardous tasks, as was
mentioned before. This creates attractiveness for these kinds of devices and pushes the
community to start relying on robotic devices to perform remedial and dangerous tasks so that
humans won’t risk their lives or waste money.
The environmental impact of this device is minimal since it runs off of battery power. Batteries
can be charged at solar panel docking stations so that the device can run an emission free life.
The only environmental impacts that the device has are the costs and processes of mining and
manufacturing the materials and parts needed. However, because the five fundamental
components of the device are made to be detachable and upgradable, rather than buying a
brand new device every time a new model comes out, components can be swapped or replaced
if needed.

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Conclusion
At this time, the team is very proud of the success and performance of the ball harvester
machine. Through the various stages from testing the prototype for the major framework,
completing a CAD model of the final assembly of the machine, physically assembling the
machine components, mounting each component to the framework, wiring the hardware
together and finally testing the final prototype, the fruit of the team’s labor has paid off. The
team has earned first place harvesting a maximum number of 12 balls.
For future purposes the team simply must continue working while alleviating economic burdens
whenever possible. While the project itself exceeded the limits of the budget, it is not to an
extent where the team can no longer continue working. Any finances that were not covered by
the budget the team will always be covered by the members of team one in hopes in bettering
member’s critical thinking and engineering skills. Once again Team One is proud and confident
that any further development on the robot will only enhance its capabilities and fulfill its
intended requirements.

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