1. 2
EXECUTIVE SUMMARY
CONTENTS
“ “James Dyson once said that Manufacturing is more than just
putting parts together. It’s coming up with ideas, testing principles
and perfecting the engineering, as well as final assembly.
Speed Deamons’ Engineering Manual will take you up on a tour through the idea behind our
prototype as well as the design process, the testing and the manufacturing steps. Each and
every step to perfecting our product and improving ourselves…
 EXECUTIVE SUMMARY 2
 RESEARCH & DEVELOPMENT 3
 SPEED DEAMONS DRIVING TO ITALY 5
 DESIGN CONCEPTS 6
 3D PRINTING 7
 MANUFACTURING 8
 TESTING – EVALUATION 10
 CONCLUSION 13

2. 3
Understanding comes when you empty your head of what you think you knowRESEARCH & DEVELOPMENT
GOAL:
To design, machine and race the fastest car
Our study in the field of aerodynamics offered the
most important contribution to our work. Valuable
research by the designer revealed the following:
The teardrop shape was our best choice because
of its aerodynamic properties
Curves help facilitate the flow of air over the
surfaces of the model
Need to eliminate turbulence on the aerodynamics
chart
Need to reduce the total pressure, which measures
the energy flow
Need to reduce aerodynamic drag
We began by identifying factors that could be
influenced, in order to study them carefully, as well
as factors that stood beyond our influence.
Factors that COULD
be influenced
Shape of the model
Wheel system
Weight of the model
Protection of the
vehicle at the finish line
Reaction times
Factors that COULD
NOT be influenced
Alignment of the track
Differences in CO2
capsules
Variability in starting
system
Atmospheric Conditions
WHAT MAKES A FAST CAR?
To understand the variables that affect the straight-
line performance of an F1 car, we need to have an
appreciation of physics. We considered the following
forces and the extent to which they could be
controlled by our design:
The thrust that propels the car forward
Drag Force
Skin Friction
Rolling Resistance
Components of Drag
Four primary aspects contribute to drag:
Pressure
Velocity
Viscosity
Body Curvature
Drag Force
Drag Force is the single
most reactive force that
resists forward motion
in an F1 car. Drag Force
is a function of air
density and the car’s
drag coefficient, cross
sectional area and its velocity.
Air density is not a variable that can be controlled
by the team and in an air conditioned environment
should be constant for all teams at the competition.
Car drag coefficient is highly dependable on the
aerodynamics of the car. To reduce drag coefficient,
our design aimed to copy the properties of a
teardrop, which has a drag coefficient of 0.04.
Car cross sectional area pushing through the air is
equally as important as it drag coefficient and must
be kept as small as possible.
Induced Drag
The flow around the sides of objects creates induced
drag. It can be reduced by streaming and avoiding
bluff shapes and flow separation.
Bernoulli’s Principle
Airflow over the top of a wing travels a
greater distance than airflow below the
wing.
The two streams of air molecules will
meet at the same time at the rear edge
of the wing, the molecules of air on
the top surface move faster than those below and this creates a
vacuum on top of the wing resulting in the creation of lift.
Thrust
The thrust that propels the car originates from the explosion
of CO2 canister. Whilst there is a degree of variability between
canisters, the amount of thrust is not a variable that can be
controlled by the team.
The thrust is a function of mass and acceleration. The lighter
the car, the greater its acceleration and the greater its terminal
velocity when the canister expires to propel it to the finish line.
To convert the full thrust into forward motion, the thrust must
be directed through the car’s center of gravity.

3. 4
RESEARCH & DEVELOPMENT
Components of Drag
Rolling Resistance
Rolling Resistance is a function of the weight of the car, friction between the wheels and
the track and bearing resistance.
In addition, rolling resistance is increased by imperfections in the track that may cause
the car to bounce and use energy from its forward motion.
Skin Friction
Skin Friction is a function of air density and the car’s surface
finish. Surface roughness was minimized by selecting a high
quality paint finish.
CRITERIA FOR SELECTION OF FINAL CAR
The process used to select the final car concept was based on the marking
criteria for the competition. This included:
• Full compliance with competition rules
• Strong design processes and analysis
• Robust design unlikely to break during extensive racing
• Fastest average times during track testing
Humidity & Temperature Effects
As part of travelling internationally, a component of the team’s
preparation included researching the environmental conditions to
ensure that the car would perform as well in Texas as it did in Greece.
Our own experience at the national finals indicated that, when
the air conditioning was turned on, an unfair advantage was
given to those cars that subsequently travelled much faster
in comparison to those that raced without air conditioning.
Humidity and temperature are the two key factors in ensuring
a perfect weight as their variation between location can mean a
weight difference of up to 0,7 grams – a huge difference for this
type of competition.
Canister Angles
As there are no limitations on the angle that the CO2 chamber
must be on, we discussed whether angling the chamber itself up
or down, would give us a speed advantage on the track.
Theoretically, even a change of 1-2 degrees would be enough to
either offset weight, by angling the jet stream down (pushing the
car up) or by angling the stream up in order to increase the down
force of the car, helping it stay stable on the track.
After testing, however, this idea was rejected on the grounds
that altering the thrust distribution on the car it created more
problems than solutions as well as slower times on the track, an
equally important element.
REYNOLDS number
A Reynolds number (Re) is a dimensionless number that assigns
a measurement of the ratio of inert forces to viscous forces
and thus quantifies the relative importance of these two types
of forces for given flow conditions. In other words, the number
expresses the ratio between the size of an object and whether it is influenced by
aerodynamics. We recognized that aerodynamics is not the determining factor for
a fast car. Factors such as weight, bearings and tether line guides were essential
determinants, which is why we gave utmost importance to these factors.
It was also very important to make the Lift Force tend to be zero, because the higher
this Force is the more probable it is for our car is to lift.
Solar cars
We were mostly inspired
from the solar cars, which
are well-known for their
low drag coefficient.

4. 5
SPEED DEAMONS DRIVING TO ITALY
We traveled to Maranello in Italy to meet Ferrari’s chief
designer, Nicholas Tombazis, whom we want to thank
for hosting a reception for us and of course for the
valuable advice he gave our team.
Nicholas Tombazis is well-known in the world of F1
cars. With perseverance, patience and, most notably,
his impressive body of work he has managed the
impossible – to be constantly in the forefront of F1 design.
Aerodynamics is one area he concentrates his work on,
seeing as, since 2007, he has been responsible for all
Italian F1 car designs at Ferrari.
We discussed issues such as aerodynamic forces – Drag
Force (Df) and Lift Force (Lf), where Drag Force is the
horizontal force exerted on the car from the nose of the
model towards the rear of the vehicle. This force depends
on the speed of the car and the aerodynamic coefficient
(Cd) which we want it to be as close to zero as possible.
Team Leader –
Design Engineer with Mr. Nicholas Tombazis
At the back side of the car there is always going to be turbulence, even
if it is considered to be little. This is because of the wing inclining down.
Therefore the wings should be designed with a teardrop shape.
ADVICES – RECOMMENDATIONS
To take into account what happens with the flow at the wheel, where the losses exist.
To try for all our airfoils not to influence the general aerodynamics of the car.
To analyze all the parameters of the aerodynamics and then test them on
an inclined plane.
To separate sections on the model, so as to analyze every part of it.
To conduct several tests on the placement of the wheels.
At the aerodynamics test the blue color means losses.
Results of the Meeting – Decisions
• Reduce the turbulence by making the airfoils smaller and designing them in a tear-
drop shape.
• Observe the airflow produced by the wheels and where losses occur cause them to
result in a tear-drop shape on the aerodynamics chart
• Reduce the angle of the wings
• Smoothen the wooden body of the model
• Turn all sharp angles into curves throughout the body
Overall
Conclusion:

5. 6
NATIONAL CHAMPIONSHIP 2013DESIGN CONCEPTS
The O.I.I.C and how to get there…
We created a framework to evaluate the designs of models
we created aiming at the best possible result.
O: Examine suggestions made by
Mr Tombazis….
I: Turbulence was observed
I: Strong indication of horizontal lift
power with lift force at desired levels
C: Modifications on the front airfoil to
reach the right alignment of the air.
Coefficient Drag (Cd): 0.62
Drag Force (Df): 0.540N
Lift Force (Lf): -0.037N
O: To achieve excellent Lift Force
I: We are still observing turbulence
I: Good horizontal force indication
and lifting force presents excellent
results, since it is zero.
C: Creating a second airfoil at the rear
of the vehicle body at the height
which the turbulence starts to
generate, giving the airflow directed
movement
Coefficient Drag (Cd): 0.40
Drag Force (Df): 0.327N
Lift Force (Lf): 0.001N
O: To design the most aerodynamic car ever
I: The lifting force is inclined towards
the negative range and exceeds
the limit deviation 0.1 we have set.
The turbulence has not been
corrected and the second airfoil is
outside the regulations.
I: Better horizontal force than previous
models
C: Changes to the second airfoil so that
it will comply with regulations
Coefficient Drag (Cd): 0.40
Drag Force (Df): 0.311N
Lift Force (Lf): -0.187N
SDWF1 SDWF2 SDWF3

6. 7
MANUFACTURING
Materials Study
The competition specification requires a balsa body and non-
metallic wings. This provides technical freedom regarding
the material selection in the design and manufacture of the
wheel assembly and line guides.
3D Printing
3D printing, otherwise Rapid Prototyping is a very modern
style of manufacture that allows a great deal of flexibility in
the way that parts are designed. As a result there is room
for more innovative designs and much more refined weight
management.
We collaborated with Mr. Michael Spanos from Materealise
and we used a 3D printer to manufacture our front and
rear airfoils, and the wheeling system as well. These were
designed using CAD software and converted to STereo
Lithography (STL) files for the 3D printer.
We selected the printing orientation to minimize any
support structures and achieve a better quality finish. The
components were undercoated and given a light sanding in
preparation for fixing to the car.
With 3D printer also, it was simple, convenient and fast to
produce and test various parts of the car.
Materials
We have researched a lot of different materials for the components of our car. The main
focus was on the material for our wheels because we realized that the material of our
wheels affected the speed of our car. We originally used ABS plus for our wheels but
found out that a potential plastic’s lower coefficient of friction improved the speed of
the car. This led us into further research to deliver a plastic which would have the lowest
coefficient of friction but would be still strong enough to handle the forces the car goes
through on its run down the track.
3d Printer (Rapid Prototyping)
Pros:
Fast part turnaround time
Little to no cost to use
Pars can be built up with great flexibility
Cons:
Can leave small inconsistencies in part
Limited to one material
Wheel Design
1. Single Bearing Design
A wheel design which contains a single ball bearing located at the middle for the wheel
to rotate about the axel.
ADVANTAGES
Simple to design
Easy to assemble
DISADVANTAGES
Highly prone to wobbling
2. Double Bearing Design
A wheel design which contains a two ball bearings instead of one.
ADVANTAGES
Extremely stable, little wobbling
DISDVANTAGES
Costs more to produce
Higher coefficient of friction due to extra ball bearing.
While the double bearing design has more disadvantages, it is extremely stable which is
something a single bearing design cannot achieve. Therefore, with the disadvantages
of the double bearing wheel able to be solved, we decided to try something new
and choose it as our design for the World Finals. We would finally able to reduce the
wobbling of wheels.

7. 8
Create Ideas – Develop InnovationsMANUFACTURING
Precision & Quality of Manufacture
To ensure that the physical product matched the design
intent, and that the 0.01mm dimensional tolerance for
the World Finals would be achieved, it was imperative to
set the Denford CNC machine within fine tolerances.
A standard Z datum at a fixed location in X and Y was
utilized to reduce the impact of tool changes. This was an
effective approach to maintain dimensional accuracy due
to the rather complex machining schedule.
Wheel Balancer
To control the vibration in the
fabricated wheels, a static wheel
balancer was developed. This led to a
consistently smoother running wheel
system.
Mass Control
The minimum mass of the car is
prescribed by the rules to be 52
grams with a 0.5 gram tolerance.
Cars have been presented as close as
possible to 54.5 grams, using coats of
paint to control the final configuration.
Surface Finish
A high quality surface finish is desired
for a range of seasons including
engineering judging and aerodynamic
performance on the track. By
increasing the consistency of coverage
across the surface, the variability is
reduced.
Axle Alignment Jig
To ensure the axles are parallel,
the axle supports need to be fitted
accurately. A jig is used to achieve this
when fixing the supports to the body.
Regulations
An issue was discovered when developing our World Car
when considering the following regulations:
T1.3 Body consists of only balsa wood and does not
include any balsa forward center line of front axle(s)
T3.7 Body to track distance cannot be lower than 3mm
T4.4.1 No part of the body is allowed to be less than
3mm thick.
T6.2 The tether line slot must be a square of 6mm in
cross section.
Manufacturing Procedure -
CNC Use
Throughout the machining process the spindle override
was set at the highest possible rate and the feed rate was
set low. This achieved a fine and smooth finish on the
car’s body surface.
Custom blocks were used with deepened canister
housing. The canister housing was deepened to a75mm
depth because of the design’s forward canister position.
A custom spindle was produced to provide suitable
support and to allow clearance on the cutting tool when
removing the material behind the canister housing.
We first fixed the spaces of the cutting tool at the three
axes. We then chose the function of the cutting tool and
we set the cut point. After that we ran the simulation of
the program with which we were going to construct our
car and then we constructed it. We tried to cut enough
model cars, so as to have the opportunity to test them
and evaluate the results.
CNC Lathe
(Subtractive Manufacture)
Pros:
 Generally more accurate (finer tolerances)
 Choice of many materials
Cons:
 Offsite (less control)
 Takes much longer to receive parts back from
manufacturer
 Higher cost to produce
 Less flexibility in design
Machining Codes
Quick Cam 3D Pro was used to convert our CAD Drawings
into machining codes. Like in a commercial engineering
workshop, we considered two main factors:
• Accuracy and quality of the finish
• Time efficiency
Stage machining processes were trialed to produce the
best quality finish, in the fastest machining time.

8. 9
MANUFACTURING
Car Body Design
Obviously the aerodynamic conditions of F1 car which produces a lot of down force are
not perfectly suitable for the straight F1 in Schools race track. However, our goal for the
new season was to design a car which looks more like a Formula 1 one.
Mass Control
To achieve the target mass, balsa blocks were weighed before
machining and huge variances were found, some as light as
50g and some as heavy as 200g. Qualitatively (no specific
calculations) it was theorized that a lighter block with heavier
components (axles, airfoils etc.) at the front of the car was best
as this improved center of gravity (CG).
Cellulose Dope
As our cars at our previous competitions, we researched into
a material that could harden the balsa and strengthen the car.
We discovered cellulose dope, that has been used on model
planes and cars for many years now. After we applied it, the
car’s strength increased and was more resistant to breakage.
The design was also made thicker so that the car would be
more solid in the design structure.
Nanotechnology
We faced problems caused by humidity in the model, which
caused considerable fluctuations in the weight. WE managed
to overcome the difficulties by applying a nano-protection
spray for wooden surfaces which also resulted in significant
improvement in weight fluctuation.
Finishing
We started by rubbing the wood with fine waterproof abrasive paper. Then we applied
cellulose dope and acrylic primer to harden the wood and make it more resistant to
chipping and splintering. The next step was applying wood putty. Then we sanded the
model again to achieve a smooth surface which would minimize air resistance, as we
were advised by Mr. Tombazis. Finally, we airbrushed the model to achieve the ideal
finish.
Weighing
Throughout the finishing process it was critical to keep weighing the car. Since
we were adding some mass by using putty, and also removing small amount of
balsa by sanding, our optimum mass targets had to carefully monitored.

9. 10
TESTING – EVALUATION
Track Testing
We conducted several sessions of live on - track testing in order to compare and record
the differences between the prototypes on track and determine our choice of wheels.
Due to the number of variables involved in track testing, it would have been impossible
to achieve times that would be retained in Texas. Despite this, however, we were able
to use it effectively to measure track time comparisons, recordings of the start, middle
and end of the race on camera, in addition to a real world confirmation of the structural
integrity of all parts.
Canister Heat Experiment
We did some research on the canister heat to determine whether this would be an
advantage or a disadvantage. We determined that when the canister’s temperature
is increased, the carbon dioxide expels form the canister more rapidly. Though we
will have no control over canister heat, we felt this was some effective research.
Reaction Times
A factor that has an effect on the competition score is the reaction time that initiates the
starting mechanism during reaction racing.
The team tested three common techniques using the thumb, finger and palm with trials
of each technique for each team member.
Quality Control
Through continuous testing on the test track by our
Construction Engineer we were able to check the strength of
materials, times and of course the consistency that our model
was able to achieve. Small improvements were needed to
achieve ultimate system stability of the wheel support system
and to ensure the correct weight according to regulations
00 .050 .100 .150 .20
Vasilis
Panos
Danae
Cristiana
Reaction Times (sec.)
0.114
0.168
0.110
0.153

10. 11
TESTING – EVALUATION
X- ray testing
To x-ray test our car we collaborated with Mr. Panos Sarlamis of the Bomb Disposal
Unit of Elliniko Police Department. He assisted us by scanning one of our test cars in a
modified x-ray machine in order to for us to see the microscopic hairline cracks caused
by the initial break of the car. We were also able to see imperfections in the bearings
where the balls inside had chipped away. We were then able to focus on strengthening
the car in the areas mostly affected by the weakness.
Bearings Research
We tested our bearings and modified them to provide the least rolling resistance
possible. We conducted an extensive research on different bearings. We then
investigated radial full steel, hybrid ceramic/steel, and several full ceramic bearings.
Track testing alone is not enough to determine the performance properties of a bearing;
spin time and peak rpm of each bearing are two crucial factors which also determine
the performance of the car. After testing each bearing for the above properties, we
finally chose full ceramic bearings, as these provided less friction than hybrid and steel
bearings, and also produced the fastest car times.
High Speed Camera
Photography was used to see what happened to the car initially after launch and in
the stopping phase of the race. We collaborated with Transam Rading company, which
assisted us by loaning us a high speed camera from Fastec Imaging Company.
The results were spectacular. We observed that our model has such a good start
up and it was seen that the car wouldn’t crash onto in the trucks sides during the
race. Although we located a problem with the wheels, because they’re not balanced
properly. That’s why we moved on different wheel system design.
Wind Tunnel Evaluation
To get an overall idea of the car’s drag and verify the results given by the VWT tests,
each car machined was placed in the Wind Tunnel, we fixed. Through comparison of
these results we were able to refine some aspects of the car. The Wind Tunnel also gave
us useful drag readings in grams. So, we verified VWT results and a drag value in grams.
We were able to determine an aesthetically pleasing yet aerodynamic design, and chose
the design that was the lightest and had the least drag.
F1 Virtual Wind Tunnel
The F1 Virtual Wind Tunnel, which we obtained in order to carry out analytical and
specialized precision measurements on the aerodynamic forces, proved extremely
helpful. With this program we carried out the first baseline measurements. It enabled us
to have detailed information on the aerodynamics of the model and to identify points
which needed improvement before moving on to the next stage in the construction of
the model.
Bearing Spin Test
Steel
Bearing 15 Spins
Hybrid
Ceramic
Bearing Type
25 Spins
Full
Ceramic
Bearing
40 Spins

11. 12
FINAL MODEL New Rules = New Game
Bearings
We applied an innovation that helped us
minimize the skin friction on the bearings
kinetic energy on the wheels, we joined the
outside of the one bearing with the inside
full rotation of the one bearing, which
means less friction, making the small
bearing makes a half turn and the large
bearing makes one quarter of a full
rotation.
Axles Stabilizer
This component is used to hold
the basic wheel axles from the
horizontal motion. It is very
important because it doesn't
allow the axles to disassemble
from the main body of the car
(Regulation T3.7).
Front Airfoil
It is designed to reduce the frontal
pressure without changing the air
direction. It has been designed and
joined to the rest of the body at 0
degrees inclination. The wing support
structure works as a secondary airfoil
that helps the wing to split the air
stream and feeds the upper part of
model and the lower part of the
model with the same amount of air.
Tether Line Guide
on Front Wing
We have designed an embedded
hoop base for the tether line
guide. This hoop is made by gold
metal, which as a material has the
least skin friction. The hoop is
sliding from the front of the airfoil
and remains stable like a wedge.
Basic Wheel Axle
This component is printed with
Retinoid, which is a very durable and
ßexible material that absorbs
vibrations. On the basic wheel axle has
been designed the inside lid of the
wheel, with the rationale of avoiding
weight on the wheel.
Down Air Duct
All the air ducts on the bottom of the
car have been designed so as to
redirect the air ßow smoothly, without
creating vortexes and on some
instances to prevent them or to
decrease them.
Rear Airfoil
The back airfoil determines the Þnal
airßow, that's why we had to make
many customizations to reach the
best outcome of the air movement.
So we concluded that the height
and the inclination of 0.9 degrees
brought us the best results.
Wheel
We used Retinoid 3D-Printed wheels, which helped us
to make them thinner owing to durability and ßexibility
of this material. As a result, each wheel is lighter and
with greater endurance than the ABS and the ABS Plus.
For example the same wheel weighs with ABS 0.60
Grammars, with ABS Plus 0.82 Grammars and with
Retinoid 0.41 Grammars. Also all materials,
except from Retinoid, were breaking at the race track.
Screw
For the proper handling of
the bearings on the axle
we used an aluminum
screw with dimensions
Vertical Airfoil
This airfoil has two properties. The Þrst
is that it helps to the aerodynamic
design. This airfoil gives the air the right
direction so that the air ducts receive
the air smoothly without creating
turbulences. The second, and most
important part of this design, is that the
particular airfoil is helping the Þnish
gate of the race track recognize the
model faster, because the height of the
airfoil is designed in a way that the rays
of the Þnish gate come into contact
before they reach the rest of the body
of the model.
Rear Wing Support Structure
At this point of our model we implemented an idea that
was conÞrmed by CFD Programs and managed to reduce
the resistance of our model to the air. We converted the
existing airfoil, adding an air duct along its length. With this
customization, we managed to eliminate the turbulences
that were created on the back of the rear wheel.

12. 13
CONCLUSION
Thank you for taking the time to read our detailed booklet.
We look forward to your favourable consideration.
Please, if you have any questions, do not hesitate to contact us.
Engineering Department
“ “