1. Lockheed Martin Vertical Take-off
and Landing Design Project and
Competition Final Report
Team Members:
Thomas Sullivan, EE/COE
Jordan Billet, EE
Kai Sen Lathrop, ME
Kevin Osman, ME
Kirin Elahi, ME
Christopher Rumasczak, ME
Sponsors:
Lockheed Martin
Society of Hispanic Professional Engineers
Binghamton University, State University of New York
August 25, 2014

2. Table of Contents
List of Figures: 3
Executive Summary 4
Introduction 5
Problem Statement 5
Pickup Mechanism 6
A. Initial Conceptual Pick-up Mechanism 6
B. Pick-up Mechanism Design 9
C. Testing 11
D. Final Design 13
Landing Gear Design 16
Flight Control Board 20
Motor, ESC, and Propeller Selection 21
Battery and Flight Time 24
Frame 25
Tuning and Flight Practice 26
Conclusion 28
Appendix 29
A. Budget 29
B. Schedule 31
i. Gantt Chart 31
ii. Timetable Strategy 34
C. Pickup Mechanism Assembly Schematics 35

3. List of Figures:
Figure 1: Competition Arena....................................................................................................... 5
Figure 2: Hopper Mechanism Concept....................................................................................... 6
Figure 3: Mechanical Sweeper Concept ..................................................................................... 7
Figure 4: Mechanical Iris ............................................................................................................. 7
Figure 5: Pickup Mechanism Pahl Beitz Chart ......................................................................... 8
Figure 6: Pickup Mechanism Pahl Beitz Analysis ..................................................................... 8
Figure 7: Makerbot Replicator 2x............................................................................................... 9
Figure 8: Early Hopper Build...................................................................................................... 9
Figure 9: Revised Hopper Design.............................................................................................. 10
Figure 10: Hopper with cable guides ........................................................................................ 11
Figure 11: Amperage / Thrust Test Instrument....................................................................... 12
Figure 12: Final Build of the Pickup Mechanism.................................................................... 13
Figure 13: Final Pikckup Mechanism Assembly...................................................................... 14
Figure 14: Mechanism Deploying 2-point Tennis Ball ............................................................ 15
Figure 15: Initial Landing Gear Design.................................................................................... 16
Figure 16: Landing Gear Schematic ......................................................................................... 16
Figure 17: Secondary Landing Gear Design ............................................................................ 17
Figure 18: Tertiary Landing Gear Design................................................................................ 17
Figure 19: Final Landing Gear Concept................................................................................... 18
Figure 20: Fiber Glass Motor Mount........................................................................................ 18
Figure 21: Laser Cut Steel Motor Mount ................................................................................. 18
Figure 22: Final Landing Gear Design ..................................................................................... 19
Figure 23: NAZE32 mounted on 3-D platform ........................................................................ 20
Figure 24: Cobra CM-2217/20 Motor Propeller Data............................................................. 22
Figure 25: Cobra CM-2217/20 Motor Specifications .............................................................. 23
Figure 26: Turnigy Plush 25 Amp ESC .................................................................................... 23
Figure 27: Flight time calculation ............................................................................................. 24
Figure 28: Hobbyking X525 V3 600mm Quadcopter Frame.................................................. 25
Figure 29: Fabricated Aluminum Frame ................................................................................. 25
Figure 30: Final PID Settings..................................................................................................... 27
Figure 31: Initial Budget ........................................................................................................... 29
Figure 32: Final Budget.............................................................................................................. 30
Figure 33: Gantt Chart............................................................................................................... 32
Figure 34: Gantt Chart............................................................................................................... 33
Figure 35: Timetable Strategy................................................................................................... 34

4. Executive Summary
While vertical takeoff and landing poses additional difficulties as compared to
conventional methods, there still lies a demand for such technology. When there is a need to take
off without access to a runway, VTOL’s disadvantages can be overlooked. With the recent rapid
increased use of unmanned aerial vehicles (UAVs), VTOL has been widely implemented into
many UAVs due to the increased portability and flexibility that such a system offers the user.
UAVs now also use VTOL’s ability to hover and land in conjunction with integrated systems
and mechanisms as a means of surveillance and reconnaissance.
Though these features can prove to be valuable, VTOL is a very complex system.
Because of this, designing a UAV capable of VTOL is a very difficult process. A popular variant
is a multi-rotor aircraft which further increases the complexity of the system due to the need for
complex controls and sensors in order to properly fly. In this competition, the challenge is to do
just that, design a multi-rotor UAV with the added challenge of the ability to collect a payload.

5. Introduction
Under the sponsorship and consultation of Lockheed Martin and the Society of
Professional Hispanic Engineers (SHPE), the Binghamton University team was able to compete
in the Boeing Vertical Takeoff and Landing (VTOL) competition. The project of building a
Quadcopter with a tennis ball pick-up mechanism from start to finish was volunteer to be
completed by the team through the collaboration of each member of the multi-disciplinary
engineering team. The main goal of the project was to design and build a Quadcopter through the
utilization of knowledge and skills from Mechanical Engineering, Electrical Engineering and
Computer Engineering. This project integrated the planning, brainstorming, designing, and
fabrication of a functioning Quadcopter and a pick-up mechanism which was to be entered into
the competition.
Problem Statement
The Boeing Vertical Takeoff and Landing competition
asks student teams to create a Quadcopter that takes off from
a designated platform and performs the task of lifting tennis
balls of different weights and then dropping them in the
designated drop zone. Each student team is given 15 minutes
to pick up as many tennis balls as possible ranging in weight
and drop them off in the drop zone. The tennis balls have
different point values associated with their weight. The
yellow balls (60g) are worth 3 points, the green balls (180g) 2
points and the red balls (300g) 1 point. The drop zone can
have no larger than a 12’’ diameter. The pick-up zone and
drop zone must be at least 50 feet away from each other and
the take-off area is half between the two. The competition
zone must at least be 15 feet away from an walls, as shown in
figure 1.The Quadcopter is required to use at least one
particular battery and part number (Turnigy nano-tech
4000mAh 3S 35-70C Lipo Pack), all other components of the
Quadcopter were determined by the team through calculation
and experimentation so that the most efficient Quadcopter can
be built and designed.
Figure 1: Competition Arena

6. Pickup Mechanism
A. Initial Conceptual Pick-up Mechanism
Based on the competition requirements and scoring rules, the team brainstormed pick-up
mechanism ideas. Three initial design concepts were chosen to be further explored based on the
team’s judgment of their feasibility and efficiency at scoring potential points; a hopper
mechanism, a mechanical sweeper, and a mechanical iris. One of the three conceptual designs
was selected using a Pahl and Beitz evaluation to be revised and built.
The hopper mechanism concept (figure 1) was inspired by the function of tennis ball hoppers.
Unlike a commercial tennis ball hopper, this mechanism requires a method to not only pick up
tennis balls, but it must also drop them off. To achieve this, the cables on the bottom of the
hopper change in tension with the assistance of a servo. When the cable is loose, the tennis balls
are able to enter and fall out of the hopper, and when the cable is taunt, the tennis balls are held
within the hopper.
Figure 2: Hopper Mechanism Concept
The mechanical sweeper concept (figure 2) relies on a scoop that moves linearly to capture
tennis balls within the mechanism. The motor used to close this mechanism would rely on a rack
and pinion gear system and guiding rods to close and open the sweeper.

7. Figure 3: Mechanical SweeperConcept
The mechanical iris concept originates (figure 3) from the closing shutter in a camera lens. The
center is covered by five blades that open and close through rotation of the outer ring. Many of
the mechanism components would have to be printed individually in order to construct an iris
large enough to fit tennis balls.
Figure 4: Mechanical Iris
The Pahl and Beitz analysis (figure 4) emphasized five different categories with individual
weighting factors based on significance. The first category, efficiency, considered each
mechanism’s operational time to successfully pick up and drop off the tennis balls. The second
category, easy to build, considered the feasibility of building a functional final prototype before

8. the competition date. The third category, ease of use, considered how easily the pilot could
operate the mechanism. The fourth category, reliability, considered the potential repeatability of
the mechanism’s operation before failure. The last category, ease of fixing, considered how easy
fixing the system would be in the case of part failure. After the team voted and averaged the
scores for each conceptual design under each category, the hopper mechanism was chosen to be
implemented in the final solution.
Figure 5: Pickup Mechanism Pahl Beitz Chart
Additionally the concept of designing a secondary system to lower the pick-up mechanism was
explored. The reason behind theoretically lowering the pickup mechanism from the body of the
quadcopter was to reduce the force applied to the unweighted tennis balls with high point value
due to the thrust of the propellers. This concept was considered as a team using a Pahl and Beitz
chart (figure 5), and it was decided that the theoretical benefits were outweighed by the
complexity and extra weight a lowering system would impose. A final test of this concept was
further explored in order to make a final decision.
Figure 6: Pickup Mechanism Pahl Beitz Analysis

9. B. Pick-up Mechanism Design
The mechanical hopper was largely designed through iterative functional prototyping through the
use of Makerbot Replicator 2x (figure 6). This tool allowed the team to 3D-Print in ABS plastic
multiple iterations of most of the components that made up the mechanical hopper and efficiently
test revisions to the design.
Figure 7: Makerbot Replicator 2x
The bottom half of the pick-up mechanism was printed and assembled to test the operation by
hand (shown in figure 7). From this iteration of the design, a friction was observed in the bend
which caused an uneven taunt to the cable that could potentially cause the tennis ball to be stuck.
To resolve this, two design changes were made; a thinner nylon cable was used, and instead of a
single strand of cable, the cable was split into two strands entering the bottom of the hopper
(shown in figure 8).
Figure 8: Early Hopper Build

10. During the concept phase of this design, it was believed that a ratcheting system would be
required to hold the necessary amount of tension within the system. This belief was debunked
through attaching a high torque servo to the cable using a 3D-Printed spool and observing that
the servo motor could hold the cable in a state of tension with the maximum anticipated payload.
By removing the need for a ratcheting system, the design was greatly simplified (figure 8) and
reduced in overall weight.
Figure 9: Revised Hopper Design
Final revisions were made to implement upper and lower cable guides (shown in figure 9) to
direct the motion of the cable and guarantee that the slack would travel equally into the bottom
two cables. The cable guides also double as the mounting points for a flexible metal bicycle
cable housing that could be lubricated to reduce friction.

11. Figure 10: Hopper with cable guides
The rods and mounting bars were cut out of standard sized aluminum in order to improve the
structural rigidity of the hopper in the case of impacts during flight. The aluminum was also light
enough to allow for the overall vehicle design to be less than twice the available thrust, which
provided for optimum pilot control.
C. Testing
The strategy for approaching the pickup zone was determined through a measured thrust
test. In order to determine if a lowering pickup mechanism would be beneficial, the minimum
height the active propellers could be from the ground before the 3 point unweighted tennis balls
would be pushed out of the pickup zone was found. In order to measure an approximate thrust, a
testing instrument was built with a multimeter, single brushless motor and propeller. The
multimeter read the supplied amperage (shown in figure 10), which was used to replicate the
same amount of thrust on a scale to measure the resultant thrust.

12. Figure 11: Amperage / Thrust Test Instrument
The supplied power was increased until the unweighted tennis balls rolled away at two set
heights, 3ft and 6ft. The resultant thrust that caused the displacement of the tennis balls is shown
in table 1. The maximum allowable thrust for a single motor and propeller combination was in
the range of 127-166g. All four motors and propellers creating this thrust individually would not
feasibly lift any vehicle off the ground with or without the 80g load of the tennis ball.
Test Height Amps * 10-2 Resulting Thrust
(g)
3 ft 1.37 166
6 ft 0.94 127
The results of the test proved that a statically mounted pickup mechanism would be the best
approach for maximizing the potential points during competition. Additionally a static system is
simple and relatively lighter in weight to a retracting mounting, which also improves the
handling of the vehicle.
Table 01: Amperage/thrust test data

13. D. Final Design
The final design preformed repeatedly with all weighted tennis ball types. After extensive
practice of piloting the quadcopter and operating the pickup mechanism, the nylon cables
stretched. The tension levels of the system were adjustable through a metal pinch that bound the
two lower cables to the spooling cable, allowing the mechanism to preform consistently.
Figure 12: Final Buildof the Pickup Mechanism
The final design includes seven 3D-Printed components, eight standard screw and nut fastener
combinations, and eight aluminum simple aluminum components. The servo used in the
mechanism is a Towardpro MG996R high torque servo motor. The components were press fit in
place, then cotter pins were later installed to allow for components to be exchanged in the case
that they break. The mechanism was rigidly connected to the quadcopter with four long M4 bolts
through the aluminum connecting bars.

14. Figure 13: Final PikckupMechanism Assembly
Competition Performance
The hopper pick-up mechanism performed consistently and well during the 15 minute
competition. Despite worries over the high torque servo motor overheating after extended use,
the servo did not fail during competition and the spare servo motor did not have to be installed.
The pick-up mechanism carried 17 points worth of tennis balls out of the pick-up zone and
brought them to the drop-off zone. The pickup mechanism deployed all of the tennis balls
towards the collection bucket, but only 5 points worth of tennis balls actually made it into the
scoring container. A possible improvement for the pickup mechanism would be to add aiming
guides for more accurately deploying the payload.

15. Figure 14: Mechanism Deploying 2-point Tennis Ball

16. Figure 15: Initial Landing Gear Design
Figure 16: Landing Gear Schematic
Landing Gear Design
The landing gear design was amongst one of the most important aspects of the project
because it was what protected the sensitive and vital parts of our quadcopter including the pickup
mechanisms, propellers, servo motor, etc. The landing gear needed to be able to withstand an
extensive amount of impact and distribute the resulting loads evenly throughout each of the four
landing gears in order to function appropriately.
After several test runs, it became clear that this particular task of the project had proven
to be one of the most trouble-some of tasks. Many parts had been damaged during these test
runs. Some parts were easily replaced such as the propellers while other parts such as the pickup
mechanism had to undergo complete reconstruction due to excessive damage. After proposing
various ideas, the fifth design had proven to be the most reliable and safe.
The first design that was
implemented utilized the landing supports
provided by the Hobbyking X525 V3
Quadcopter Frame. The landing legs were
made of black glass fiber. After the pickup
mechanism was made however, 3D printed
extensions were bolted onto the landing
legs in order to protect the mechanism and
absorb the shock/impact of landing
(labeled as “Landing Feet” in the detailed
drawing depicted below). After one or two
test runs, the 3D printed landing feet snapped as well as one of the fiber glass legs. This design

17. Figure 17: Secondary Landing Gear Design
Figure 18: Tertiary Landing Gear Design
led to the realization that the sharp corners on the extended legs propagated cracks and a totally
different design for leg extenders should be addressed.
In order to evenly distribute stress across the landing gears, the next design offered
rounded edges. The figure below is a CAD of our landing gear that was tested as well. The
fiberglass legs were used again. This time, the 3D-printed extensions were rounded and bolted
onto the legs. After a few attempts however, the 3D-printed extenders snapped and it was noted
realized that 3D-printed material was not a good shock absorber for this amount of impact.
The third design had suggested steering
away from the fiberglass legs and replacing them
with aluminum rods to support each of the four legs
during impact. The aluminum rods would be
connected to the quadcopter via the 3D-printed rod
adapters shown in the figure below. Lastly, pipe
insulation would be zip-tied to the bottom of the
rods in order to absorb the impact and distribute the
stress evenly. This design was not utilized since it
the rod adapters connecting the rods to the frame
were made of ABS (3D-printing material). This design led to the conclusion that no parts of the
landing gear should be made of ABS and a new perspective should be considered when
brainstorming ideas for this prolonging dilemma.

18. Figure 20: Fiber Glass Motor Mount
The landing gear shown below differentiated from the previous designs and led to a
major breakthrough in the landing gear dilemma. Each of the four legs had two parallel sheets
bolted together in an “L” shape in order to support the major impact of each landing. During the
test runs it was noted that the weight of the aluminum rods were an issue and consumed a lot of
battery power. And with no rubber-like material to serve as an initial dampener, there was a lot
of stressed imposed on the quadcopter. As a result, the pickup mechanism had cracked and one
of the motor mounts had snapped, and new laser cut, 1/8 inch hot rolled steel motor mounts
replaced the original fiber glass motor mounts for durability. Images of the above described
landing gear design and motor mount comparison are shown below.
Figure 21: Laser Cut SteelMotor Mount
Figure 19: Final Landing Gear Concept

19. Shown below is the final landing gear design. It is almost identical to the previously
portrayed design, however a few inches of the aluminum extenders were shaven down. To make
up for the lost length, cut-outs of tennis balls were used to make up for the lost length. This
allowed the Quadcopter to be light enough to take off vertically, durable enough to embrace hard
impact, and allowed the tennis ball material to cushion most of the stress from landing. As shown
below the length of the landing gear allowed the material to dampen the impact absorb the initial
shock of each land, yet allowed the pickup mechanism close enough to the ground to pick up
tennis balls. This design had proven its usefulness during the competition when it prevented the
quadcopter from getting damaged as it hit the gymnasium wooden floors at a rather rapid rate.
Figure 22: Final Landing Gear Design

20. Flight Control Board
Initially we thought the flight board should be where we allocate a good portion of our
budget to. This turned out not to be the case, and going with a “keep the design simple
approach” would have been a better strategy and is what we ended up doing in the end.
After doing much research we found that the APM 2.6 had very great reviews and we thought
that it would be a great choice. This controller offered G.P.S. capabilities that were advertised to
make the flight more stable and be more intuitive for the operator. Once we received the board
we ran into a number of issues implementing it. Most of them coming from the complex firm
where and tuning of the PID settings. After working with this controller for a couple weeks the
team got in contact with another student that has work with quad copters for a number of years as
a hobby. His recommendation was to go with an open sourced flight controller the NAZE 32.
We gave it a shot because this controller was only about $25 when the higher end one we had
and could not get to work was $250. After receiving this flight control board we had our copter
airborne within hours and fine-tuned within the next couple days. Two big lessons learned here
are.
1. Keeping a design simple is a great approach to many challenges with a tight time
schedule because the implementation of a complex idea is very hard with limited time
and resources.
2. The best information will normally come from someone with experience rather than other
sources that may be bias or not applicable to a certain application.
Figure 23: NAZE32 mounted on 3-D platform

21. Motor, ESC, and Propeller Selection
In choosing the proper motors for the Quadcopter, the desired flight performance of the
Quadcopter along with the current providing capabilities of the battery were considered. A set of
low KV rating motors with large propellers was the best motor-propeller combination for a
Quadcopter that required a lot of thrust and did not need to be agile, whereas a set of high KV
rating motors with small propellers was the best motor-propeller combination for a Quadcopter
that required a high level of agility, but a low amount of thrust. Agility was not required from our
Quadcopter so a motor with a low KV rating with a large propeller seemed to be the best choice,
however too much thrust and the tennis balls would scatter before the Quadcopter would be able
to successfully capture them. It was required to generate an amount of thrust suitable to not only
hover effectively, but also to lift one or more tennis balls while still maintaining stable flight.
The amount of thrust required was decided upon so that the Thrust to Weight ratio was
greater than one. The total weight of the Quadcopter was 994 grams, and it was designed to be
able to pick up two of the 300 gram tennis balls without losing any capability of flight, so it was
determined that the total amount of thrust required to be generated by the motor-propeller
combination must exceed 1594 grams.
To generate the amount of thrust required to allow the Quadcopter to hover demanded the
motors to draw a certain amount of current from the battery. The battery used was the Turnigy
nano-tech 4.0 4000mAh 35-70C High Discharge Li-Po battery. The maximum continuous
supplied current rating of the battery was determined by multiplying 4000 mAh by 35, the C-
rating, which gave 140 Amps of continuous current. This meant that all of the electrical
components present on the Quadcopter could draw no more than 140 Amps continuously in
order to ensure safe operation.

22. With the aforementioned criteria taken into consideration, the Cobra CM 2217/20 motors
were chosen along with 11 inch propellers with 4.5 inch pitch. This motor-propeller combination
was advertised to yield 1012 grams of thrust per motor- propeller combination as shown below.
Figure 24: Cobra CM-2217/20 Motor Propeller Data
Multiplying by four for each motor-propeller combinations gave a total advertised thrust
of 4048 grams which would provide the Quadcopter with a more than suitable amount of thrust.
The maximum continuous current listed for the motors was listed as 20 Amps as listed below.
Multiplying by four gave the total maximum continuous current that would be drawn from the
four motors. With an 80 Amp maximum current draw from the motors, and a combined current
draw of around 5 Amps by the flight controller and servo motor, the total maximum amount of
current that could potentially be drawn from the battery was well within the 140 Amp maximum
continuous current rating of the battery.

23. Figure 25: Cobra CM-2217/20 Motor Specifications
The Cobra CM 2217/20 motors were therefore a suitable motor choice for the
Quadcopter, and needed ESCs to transform the DC supplied by the battery to three phase AC,
which was required by the three phase brushless motors. The ESCs needed to be able to handle
the distribution of at least 20 Amps of current to each of the motors continuously, therefore the
Turnigy Plush 25 Amp Electronic Speed Controllers were chosen in order to safely and reliably
route power to the motors, and to the servo motor, used to control the pickup mechanism, using
the built in BECs (battery eliminator circuits) of the ESCs. An image of the ESC with BEC
connector is shown below.
Figure 26: Turnigy Plush 25 Amp ESC

24. Battery and Flight Time
The only restriction of the parts to be chosen for the Quadcopter was the battery, which
was the Turnigy nano-tech 4.0 4000mAh 35-70C High Discharge Li-Po battery. The main
objective was to maximize the total time that the Quadcopter could fly on a single battery in
order to minimize the number of battery changes. The estimated value for the total flight time
was calculated by approximating the total current draw from each of the four motor-propeller
combinations to be 40 Amps, half that of the maximum continuous current the motors drew from
the battery, multiplying the 40 Amps by 11.1 Volts, the voltage supplied by the battery, to get the
total power drawn from the battery. Then, the total energy of the battery was calculated by
multiplying 4000 mAh by the total voltage across the battery. Finally, the calculated total energy
of the battery was divided by the total power to give the total approximated flight time. The
calculated values are shown below.
Figure 27: Flight time calculation
During the 15 minute long competition, only two battery changes were necessary, which showed
that the approximated flight time was accurate for the duration of the competition.

25. Frame
The preliminary frame choice was the Hobbyking X525 V3 600mm quadcopter frame
(Figure 1). This frame seemed to be a wise choice for several reasons. The arms are made of
lightweight aluminum while the other components are fiber glass, resulting in a low total weight
which would require less thrust, thus lowering the chance of blowing away the low weight, high
point payloads. The modular design of was an added benefit which gave us the ability to change
out broken parts in case any damage occurred due to test flights and tuning. Another key feature
of the fame was the included shock absorbing landing gear. The spring-loaded mounts gave us
the availability to either design our pickup mechanism around them or modify them in order to
reduce impact stressed on the mechanism. Last but certainly not least was the cost factor. With a
relatively low budget for multiple big tag items, choosing an inexpensive frame gave the budget
more wiggle room to use higher quality choices for some of the more crucial components.
Figure 28: Hobbyking X525 V3 600mm Quadcopter Frame
A mere five days before the competition date, catastrophe struck. While practicing and
tuning, the quadcopter crashed, bending an arm, and breaking multiple frame components. With
no time to order a new frame online and wait for it to ship, and very little money left in the
budget, we decided that the only option was to build a new frame from raw materials. Using
aluminum square tubing and sheet aluminum, we built a rugged, simplified, heavier version of
the Hobbyking frame. While although the new frame’s weight proved more difficult to approach
lighter weight balls, the controllability was improved dues to the increased moment of inertia.
Figure 29: Fabricated Aluminum Frame

26. Tuning and Flight Practice
Once the quadcopter was fully assembled, the Acro NAZE32 flight control board along
with the Turnigy Plush 25 Amp Electronic Speed Controllers had to be tuned and calibrated for
flight. The NAZE32 used the Crossplatform configuration tool, Cleanflight, a Google Chrome
Add-On, for tuning and calibration. Before the flight controller was tuned and the ESC’s were
calibrated, the propellers were removed from the Quadcopter. This was a necessary step which
was carefully taken prior to every tuning/calibration in order to avoid damaging/destroying the
Quadcopter, and to avoid the possibility of injury.
The initial phase of tuning/calibration included customizing the NAZE32 to control our
particular Quadcopter rotor arrangement. Within Cleanflight, there were offered multiple
different flying modes depending on the type of aircraft that was to be controlled. Since our
particular machine was a Quadcopter arranged in the X-configuration, that choice was selected.
Cleanflight offered the user the ability to calibrate the accelerometer and gyroscope present in
the NAZE32 by prompting the user to move and rotate the Quadcopter about its various axes.
Next came perhaps the most critical phase of tuning/calibration, which was ensuring that the
NAZE32 was successfully receiving the commands sent by the Turnigy 9x 9 channel transmitter,
and that upon reception, the flight controller was interpreting those commands properly. This
was done by means of a feature offered in the Cleanflight software which allowed the user to
increase throttle, pitch, yaw, and roll via the input joysticks on the transmitter. It was at this stage
in the tuning where it was most important for the propellers to be removed from the motor
armatures because during this part of tuning the user is prompted to move the joysticks to their
maximum positions so the flight controller can properly calibrate the ESC’s to send the correct
amount of current to the correct motor. Both the direction as well as the speed of the rotation of
the motors was monitored for the duration of this stage of tuning to ensure their proper
performance. Another feature offered by Cleanflight was the customization of different flight
modes that the operator could switch between during operation of the Quadcopter. The user
could choose which frequency band to allocate to the different modes of flight on a designated
channel of transmission. Different flight modes were experimented with over the course of
tuning, however the particular flight mode which was found to be most reliable was Angle mode,
which used the flight controller’s accelerometer and gyroscope to keep the Quadcopter level
when the user is not providing any inputs to the system.
This mode of flight required calibration, however, and proved to be one of the more
challenging aspects of the project. In this stage of tuning, the flight controller’s PID
(Proportional-Integral-Derivative) settings had to be customized to the specific design of our
Quadcopter.
Each of the three settings were modifiable coefficients responsible for the control of the
Quadcopter, and each of the coefficients served a unique purpose in error mitigation. The P part
of the PID controller produces an output value that is proportional to the current error value, and
this control coefficient is the most responsible for the stability of the system. A P value that is
too high will result in an over-sensitive system. Too low a P value and the system will seem

27. sluggish and unresponsive to any user inputs. The I part of the PID controller produces an output
based on the sum of the instantaneous error over a period of time, and this control coefficient
allows settling time to be reached more rapidly than in a strictly proportional control system. In
other words, the I value effects how quickly the system corrects error. The D part of the PID
controller produces an output based on the slope of the error over a given amount of time, and
primarily serves to amplify user input.
In order to effectively tune the Quadcopter, each of the PID coefficients were adjusted
starting with the P setting. Once the P setting was set to an optimal value, and the Quadcopter
could hover stably, the I and D parameters were modified until the Quadcopter was fully
controllable. The final settings for the PID coefficients were set in Cleanflight, and a picture of
those settings are shown below.
Figure 30: Final PID Settings
Upon completion of successfully tuning the Quadcopter, the final and perhaps most
challenging phase of the project began; practicing piloting the Quadcopter. Although the
Quadcopter was fully controllable, and operational, piloting the Quadcopter effectively proved to
be very challenging and demanded a lot of time to be devoted to practicing. Pilot practice
involved setting down a group of tennis balls in a dedicated circular area, and hovering over the
balls until it was suitable for the pilot to descend on top of a ball, lock it into the pickup
mechanism by flipping a switch on the transmitter, take off with the ball, hover over a five gallon
bucket, and then release the captured ball into the bucket. The piloting practice attempted to
model the environment of the competition as closely as possible, while making it more difficult
for the pilot during testing than it would be during competition.

28. Conclusion
Despite all of the time spent on practicing piloting, in order to have performed better
during the competition more piloting practice was necessary. During competition, 5 balls were
successfully dropped in the drop zone, and another 6 were dropped close to, but did not land in
the drop zone. Out of all of the teams to have competed, the Binghamton University team placed
second, which a great achievement was considering all of the other teams consisted of senior
engineering students competing for a grade, while the Binghamton University team was
comprised of juniors all of which were not competing for a grade. Also, the Binghamton
University team was the only other team to have successfully engineered a fully functional
Quadcopter which accomplished all required tasks and met all project requirements. An even
greater achievement though, was the technical and professional skills that were developed by all
members as a result of being involved with this project. The collaboration of engineering
students from different backgrounds allowed for each member to understand the unique
importance of their teammate’s respective engineering fields of study, and to reinforce the
effectiveness of teamwork. This project also allowed each member to experience the progression
of a technical project from start to finish, to witness and cope with unforeseen issues, and to
complete the project while remaining within the constraints of a fixed budget and deadline.
The Binghamton University team would like to thank all of the Lockheed Martin staff
members for their consultation, time, and for providing us with all of the opportunities and
learning experiences this project has offered us.

29. Appendix
A. Budget
The initial and final budget is shown in figures 2 and 3 below. Figure 2 documents the
initial budget that was made at the start of the project and does not include tax estimates or
shipping costs. The final budget is shown in figure 3 and totals $855. 89. From the initial budget
to the final budget there was an increase of roughly $200, this increase was due to unforeseen
malfunctions with parts that could not be assumed at the start of the project, it also accounts for
the design changes that the pick-up mechanism underwent in order to make the Quadcopter as
efficient as possible. A requirement of the project was to adhere to the $1000 budget set down,
which the Quadcopter successful did.
Figure 31: Initial Budget

30. Component Quantity
Cost
(Each)
Total
Cost: Tax Shipping
Grand
Total Hardware: Tax:
controller (2.6+ apm) 1 $159.99 $159.99 $0.00 $0.00 $159.99 $4.98 $0.00
GPS Unit 1 $79.99 $79.99 $0.00 $14.19 $94.18 $3.78 $0.30
Motors 6 $30.99 $185.94 $0.00 $17.25 $203.19 $5.98 $0.48
ESCs 6 $13.60 $81.60 $6.53 $5.00 $93.13
Frame 1 $17.30 $1.38 $2.25 $20.93
Propellers 8 $3.16 $25.28 $0.00 $13.30 $38.58 $5.99 $0.48
Transmitter/Receiver 1 $79.35 $79.35 $0.00 $12.75 $92.10 $4.49 $0.36
Hardware/Misc. 1 $41.81 $41.81 $2.95 $0.00 $44.76 $6.63 $0.53
Battery 2 33.7 67.4 0 11.63 79.03 $9.96 $0.80
Naze 32 Flight Control
Board 1 30 $41.81 $2.95
Total $671.26 $10.86 $64.74 $855.89
Figure 32: Final Budget

31. B. Schedule
i. Gantt chart
On the following pages is the Gantt chart used by the team for the duration of the project.
Most of the tasks had been completed either one day before or the day that it had been due. The
milestones of the Gantt chart had been finished on time (some of which include the Preliminary
Design Report, the Critical Design Report and the Final Design Report). However some tasks
had taken longer than expected. Two tasks that were noted to take the longest had been the final
design of the pickup mechanism and the landing gear design. The landing gears had been one of
the most serious issues of the project and had resulted in constant damaging of the pick-up
mechanism. Because of this, the landing gear and the pickup mechanism simultaneously were
under constant revision and replacement.

32. Figure 33: Gantt chart

33. Figure 34: Gantt Chart

34. ii. Timetable Strategy
Depicted below is the planned strategy undergone during the competition. Each run
assumed in this table that the pickup mechanism would only pick up one ball at a time. Only one
of the runs was an exception and was projected to earn a score of four points (two red tennis
balls). The reason for this exception was that by chance two red tennis balls were going to be
right next to each other during at least one instance of this competition). This timetable assumed
that the pickup mechanism had been successful in picking up both balls. Seventeen points were
not earned during this competition however. Although the quadcopter had picked up and
dropped each ball at the approximate times during the competition, the task of dropping the balls
at the appropriate drop-off zone had proven to be harder than expected.
Figure 35: Timetable Strategy

35. C. Pickup Mechanism Assembly Schematics