Technical Note
Design and Testing of an Unmanned Aerial Vehicle
Manufactured by Fused Deposition Modeling
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Ionut Stelian Pascariu 1 and Sebastian Marian Zaharia 2
Abstract: The capacity to manufacture complex structures directly without the need for a mold gives additive manufacturing (AM) technologies a major advantage compared with conventional manufacturing. An interesting and challenging field is to manufacture unmanned
aerial vehicle (UAV) components and models using three-dimensional (3D) printing. This study focuses on the design, preliminary aerodynamics analysis, manufacture, and assembly of a small UAV using fused deposition modeling (FDM) technology. From the preliminary
aerodynamic analysis of the UAV model it was found that the highest Cl =Cd of the UAV model is 14.67 at a 4° angle of attack, which
corresponds with cruise airspeed of 20 m=s. The UAV model developed in this paper presents dense ribs for wings and formers for fuselage,
all of them manufactured by FDM technology. The study also includes a description of the 3D printing procedure of the components of the
UAV model and the results of the flight tests. Following the flight tests, it can be said that the UAV model made by FDM technology is stable
and has a wide airspeed range available, stall characteristics are good, and it operates with good aerodynamic characteristics and high maneuverability. Thus, the manufacturing technique presented in this paper can be used in the fast and efficient manufacture of scale aircraft
prototypes with the purpose of determining the flight performance by conducting flight tests. DOI: 10.1061/(ASCE)AS.19435525.0001154. © 2020 American Society of Civil Engineers.
Author keywords: Design; Unmanned aerial vehicle; Aerodynamic analysis; Fused deposition modeling; Flight tests.
Introduction
Unmanned aerial vehicles (UAVs) are pilotless aircraft that are
controlled from a station with the help of a remote control, or independently by means of flight programs with global positioning system
(GPS) devices and sensors installed on the aircraft (Renduchintala
et al. 2019). UAVs have been developed to perform military and civil
applications, such as reconnaissance missions, attack missions rescue
missions, surveillance of wildlife, border patrols, firefighting, agricultural surveillance, or acquisition of weather data. In the manufacture
of unmanned aerial vehicles, composite materials, lightweight metal
alloys, injection-molded foam, or wood are used (Skawiński and
Goetzendorf-Grabowski 2019).
A recent method of creating structures is represented by additive
manufacturing technology. Additive manufacturing technology includes a wide range of new technologies for the exact manufacture
of components directly, from digital three-dimensional (3D) models with minimal human factor intervention. One of the most
commonly used additive manufacturing (AM) technologies in the
manufacture of UAV models is fused deposition modeling (FDM)
due to the low cost of printers and materials used (Goh et al. 2017).
A recent paper (Hassanalian and Abdelkefi 2017) presented the
classification of UAVs by weight according to the regulations in
force (CASA 2002; CAA 2012).
1
M.S. Student, Faculty of Technological Engineering and Industrial
Management, Transilvania Univ. of Brasov, B-dul Eroilor 29, Braşov
500036, Romania. Email: ionut.pascariu@student.unitbv.ro
2
Lecturer, Faculty of Technological Engineering and Industrial Management, Transilvania Univ. of Brasov, B-dul Eroilor 29, Braşov 500036,
Romania (corresponding author). ORCID: https://orcid.org/0000-0002
-8636-5558. Email: zaharia_sebastian@unitbv.ro
Note. This manuscript was submitted on October 11, 2019; approved on
February 5, 2020; published online on May 7, 2020. Discussion period
open until October 7, 2020; separate discussions must be submitted for individual papers. This technical note is part of the Journal of Aerospace
Engineering, © ASCE, ISSN 0893-1321.
© ASCE
The intensive research demonstrated by scientific articles and patents for invention dedicated to the additive manufacturing of UAV
models reflects the practical importance of this paper. The manufacture
of unmanned aerial vehicles using AM technologies represents a highly
researched field by universities (University of Southampton, University
of Virginia, and University of Malaysia Pahang) and research institutes
such as the Massachusetts Institute of Technology (MIT) Lincoln
Laboratory (Stern and Cohen 2013). Another important research direction is manufacturing by AM technologies of aircraft models for
wind-tunnel tests (Artzi and Kroll 2010; Zhu 2019; Zhu et al. 2019).
A team of engineers from Advanced Manufacturing Research
Centre (AMRC’s) New Design and Prototyping Group designed,
manufactured, and tested a wing UAV made of acrylonitrile butadiene styrene (ABS) using FDM technology (AMRC 2019). A recent study (Azarov et al. 2019) presented the design, analysis, and
manufacture of a resistance framework of a UAV using 3D printing
of a continuous fiber-reinforced composite.
Also, 3D-printed periodic lattice structures (Moon et al. 2014)
and sandwich panels (Dikshit et al. 2017, 2018; Khan et al. 2019)
represent a topical configuration for the manufacture of wings of the
unmanned aerial vehicles. Recently, unmanned aerial vehicles models were manufactured that were prepared for flight for maritime
patrol (Ferraro et al. 2014), and for which the aerodynamic analysis and wind-tunnel tests (Ahmed and Page 2013) or flight tests
(Skawiński and Goetzendorf-Grabowski 2019) were conducted.
However, following the research of the current state of knowledge
regarding the manufacture of UAVs, the tendency of developing small
aircraft manufactured by AM technologies was highlighted. The purpose of this paper is to investigate feasibility and practicality of an
UAV model that is manufactured using FDM technology.
Aircraft Design
In order to make the 3D digital model of the aircraft, the overall dimensions needed to be stated. These dimensions took into
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Fig. 1. UAV model: (a) designed in SolidWorks software; and (b) divided for 3D printing of components.
account the dimensions of the printing platform (200 × 200 ×
180 mm) of the Zortrax M200 Plus printer (Zortrax S.A., Olsztyn,
Poland). In designing the aircraft, the economic, technological, and
assembly aspects were taken into account.
The aircraft model was designed in SolidWorks 2016 version 24
starting from a hand-drawn sketch. In the design phase of the UAV
model, two inputs constrains were imposed: wingspan and wing
geometry (straight wing with 180-mm constant chord). The UAV
model must be removable and easy to carry and handle. Thus, a
1,250-mm wingspan will allow the user to manufacture the entire
wing simultaneously because the wing is made up of four sections,
which easily fit into the print volume of the Zortrax M200 Plus printer.
The assumed chord value and wingspan have to satisfy the
constraint of the minimum wing area. Given the weight of the
UAV model (M UAV ¼ 2.2 kg), gravitational acceleration (g ¼
9.81 m=s2 ), density to sea level (ρ ¼ 1.225 kg=m3 ), maximum
lift coefficient (Clmax ¼ 1.196), and minimum airspeed (V min ¼
12 m=s), the minimum wing area (Smin ) is calculated as follows:
Smin ¼
2 · M UAV · g
δ · Clmax · ðV min Þ2
Preliminary Aerodynamic Analysis
Airfoil Selection
ð1Þ
The minimum wing area calculated with relation Eq. (1) has the
value of 20.45 decimeters2 (dm2 ), which is smaller than the value of
the wing area of the UAV model (22.5 dm2 ).
The wing has been positioned at the top of the fuselage, which
determines a good stability and reduces the chances of an aircraft
wing impact to the ground. The wing used for the UAV model is a
straight wing with a constant chord of 180 mm, with a dihedral
angle of 4° and a NACA 4415 (National Advisory Committee
for Aeronautics, Washington) airfoil (the selection methodology
is described in the “Airfoil Selection” section). The fuselage has
a monocoque structure and has the following components: skin
and formers. This building solution was chosen so as to use the
interior space of the fuselage as efficient as possible, but also to
make the assembly as easy as possible.
For the empennage was chosen a classic configuration with
horizontal empennage (horizontal stabilizer and elevator) and vertical empennage (vertical fin and rudder) embedded in the fuselage
tail. The airfoil for the horizontal stabilizer and vertical tail of
the UAV model is the symmetrical airfoil NACA 0008 (National
Advisory Committee for Aeronautics, Washington). The symmetrical airfoil NACA 0008 has been used in previous UAV designs
(Boutemedjet et al. 2019; Burton and Hoburg 2018) for the
horizontal and vertical tail surfaces.
With the help of the empennage, the stability of the aircraft is
ensured, and at the same time it offers the possibility to perform
© ASCE
maneuvers to change the direction of the flight, allowing the pitch
and yaw motion.
The landing gear of an aircraft makes it possible to run it safely
on the ground without damaging the aircraft during runway excursions, take-off, and landing. The landing gear configuration chosen
for this aircraft is the fixed tricycle landing gear consisting of two
side gears and a nose gear. The nose gear is not controllable, with
the direction of the plane being controlled from the rudder control.
The main wheels are located in the trailing edge wing behind the
center of gravity of the aircraft.
The last step in the design phase was the assembly of the UAV
model [Fig. 1(a)], followed by the division into simple components,
which allowed the manufacture by FDM technology using the
Zortrax M200 Plus printer [Fig. 1(b)].
For the selection of the aerodynamic airfoil of the UAV model, a comparative study was carried out between four types of airfoils (NACA
2415, NACA 63-018, NACA 4415, and EPPLER 545, National
Advisory Committee for Aeronautics, Washington), analyzed with
Profili version 2.3 software. The aerodynamic profiles were analyzed
at Re ¼ 200,000, at a variation of the angle of attack between −5°
and 10°. In the wing airfoil selection methodology, there are different
graphs that describe the characteristics of each airfoil when compared
with other airfoils. The following graphs are important when evaluating the performance of an airfoil: variations in lift coefficient versus
angle of attack [Fig. 2(a)]; variations of drag coefficient versus lift
coefficient [Fig. 2(b)]; and variations of lift-to-drag ratio versus angle
of attack [Fig. 2(c)]. Considering the comparative analysis, for the
wing of the UAV model, the NACA 4415 profile will be used because
it has the following advantages: the highest lift coefficient, the lowest
drag coefficient, and the best lift-to-drag ratio.
Aerodynamic Analysis of UAV Model
On the market of aerodynamic performance analysis software (with
free versions for use) there are several programs like CMARC
version 5.0, XFOIL version 6.99, XFLR5 version 6.47, and PANUKL version 2.0 (Goetzendorf-Grabowski and Mieloszyk 2017),
for aircraft models. These programs are reasonable and inexpensive
options for obtaining results starting from the wing airfoil and reaching the polar curve of the modeled aircraft (Park et al. 2018). For
the aerodynamic analysis of the UAV, XFLR5 software was used
because this code allows analysis at low Reynold numbers.
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Fig. 2. Aerodynamic coefficients as functions of the angle of attack: (a) variations of lift coefficient versus angle of attack; (b) variations of drag
coefficient versus angle of attack; and (c) variations of lift-to-drag ratio versus angle of attack.
Fig. 3. Aerodynamic analysis of the UAV aircraft using the XFLR program: (a) methodology for obtaining the preliminary aerodynamic results of the
UAV model; and (b) modeled UAV aircraft.
After the 3D model of the UAV is obtained, the XFLR5 program
allows different algorithms to be used to estimate the aerodynamic
coefficients and stability derivatives, such as the lifting line theory,
the Vortex lattice method, or the 3D panel method (Lesprier et al.
2015).
There are studies that compare and validate the preliminary
aerodynamic results obtained under the XFLR5 program with those
obtained in the aerodynamic tunnel (Communier et al. 2019; Angi
and Huminic 2015). The aerodynamic performance calculation
methodology of the UAV model is described in Fig. 3(a). The
first stage in the aerodynamics analysis of UAV was to determine
the value of the Reynolds number. Kinematic viscosity has been
calculated with the following parameters: altitude ¼ 100 m and
temperature ¼ 20°C, and result is υ ¼ 1.56224 × 10−5 m2 =s. Using kinematic viscosity of 1.56224 × 10−5 m2 =s, speed of 20 m=s,
and mean aerodynamic chord ðMACÞ ¼ 0.18 mm, the Reynolds
number (Ananda et al. 2015) was calculated with the value of Re ¼
230,440. The values of the lift and drag coefficients were calculated
© ASCE
with the 3D panels method by using XFLR5 code for a wing with
the wingspan of 1,250 mm and chord of 180 mm [Fig. 3(b)].
Starting from the Reynolds number, the following results were
determined: drag polar of NACA 4415 airfoil (for wing) and NACA
0008 airfoil (for empennage), drag polar of wings, and drag polar of
the entire UAV model. The calculation method used by the XFLR
program does not allow for the aerodynamic coefficients to be
computed after the stall of the air flow, and for this reason, the analysis of the UAV model begins at an angle of attack sequence from −5°
to 13° (Communier et al. 2019). For preliminary aerodynamic analysis of the UAV model, in XFLR5 program, Fixed Speed Type 1
analysis was used where the speed is constant (20 m=s).
The variation of the aerodynamic coefficients is important for the
flight tests because the results that are obtained describe the first aerodynamic performances of the UAV model. For the assessment of the
aerodynamic performances of the UAV model, the lift coefficient
values (Cl ) and the drag coefficient values (Cd ) must be known at
each angle of attack; in widespread use is the method by which
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Fig. 4. Polar curves of UAV model obtained in the XFLR program: (a) variation of the lift coefficient according to the angle of attack; (b) variation of
the drag coefficient according to the angle of attack; and (c) variations of lift-to-drag ratio according to the angle of attack.
Additive Manufacturing of UAV Model Components
Table 1. Technical specifications of UAV model
Parameter
Length
Height
Wingspan
Airfoil wing
Airfoil empennage
Surface wing
Mean aerodynamic chord
Dihedral wing
Maximum lift coefficient
Drag coefficient
Wing loading
Value
835 mm
283 mm
1,250 mm
NACA 4415
NACA 0008
22.5 dm2
180 mm
4°
1.196
0.107
97.77 g=dm2
the aerodynamic characteristics are in the form of a graphic called an
aircraft polar. Thus, the polar of the UAV model obtained from the
XFLR5 program is represented by a curve of the variation of the lift
coefficient [Fig. 4(a)] or the drag coefficient [Fig. 4(b)] according to
the angle of attack. Cl =Cd can be used to determine the angle of attack
and the airspeed corresponding with the best aerodynamic efficiency.
The highest Cl =Cd of the UAV model is 14.67 at a 4° angle of attack,
which corresponds with a cruise airspeed of 20 m=s.
The main geometric and aerodynamic characteristics of the
UAV model resulting from the preliminary aerodynamic design
and analysis are described in Table 1.
© ASCE
UAV components were manufactured using the Zortax M200 Plus
printers within the Department of Manufacturing Engineering, Faculty
of Technological Engineering and Industrial Management, Transilvania University of Brasov. This type of printer works on the FDM principle by melting the material (filament) in a heated extrusion nozzle
and deposition of the material on the plate layer by layer until the desired component is obtained (Boschetto et al. 2016). The Zortrax M200
Plus printer has a maximum print volume of 200 × 200 × 180 mm,
the nozzle diameter is 0.4 mm, the plate is provided with perforations
for the adhesion and attachment of the layers of the component to the
base, and it works with a 1.75-mm-diameter filament. The following
materials were tested for the manufacture of aircraft components:
Z-PLA Pro, Z-ABS (Zortrax S.A., Olsztyn, Poland), and Z-Glass
(Zortrax S.A., Olsztyn, Poland). After the fuselage and wing sections
were made from these the three types of materials (Z-PLA Pro,
Z-ABS, and Z-Glass) it was found that the large parts manufactured
from the Z-ABS material contracted during the solidification process and their assembly is difficult to be performed. In conclusion,
Z-PLA Pro and Z-Glass materials with the properties described in
Table 2 were used to manufacture the components of the UAV model.
Manufacturing of the Fuselage
In order to manufacture the fuselage, it was divided into six sections during the design stage so it would fit in the maximum print
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Table 2. Properties of materials used in the manufacture of UAV model
components
Material
Property
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Tensile strength (MPa)
Breaking stress (MPa)
Bending stress (MPa)
Flexural modulus (GPa)
Glass transition temperature (°C)
Specific density (g=cm3 )
Z-PLA Pro
Z-Glass
28.78
27.1
58.6
1.83
48.82
1.426
39.57
34.61
55.4
1.17
78.06
1.409
Source: Data from Zortrax (2019).
volume of the Zortrax M200 Plus printer. After the fuselage was
sectioned, each section was exported from the SolidWorks 2016
design program in Stereolithography (STL) format in order to
be uploaded to the Z-Suite program. In the manufacture of the
fuselage sections, PLA Pro material with a layer thickness of
0.14 mm and an infill density of 40% was used. For all the fuselage
sections, the manufacturing process [Figs. 5(a and b)] was identical: the stereolithography (STL) model was imported and the
manufacturing program code was obtained, followed by the actual
manufacturing process, removing the sections from the plate, and
removing the support material.
Manufacturing of the Wing
For the manufacture of the wing, the wing needed to be sectioned
because the size of the wing exceeded the volume of the Zortrax
M200 Plus printer. Both the right and the left half-planes were
divided into four sections, two sections of 125 mm corresponding
to the area of the ailerons and two sections of 150 mm corresponding
to the flaps area. The material from which the eight sections of the
wing were manufactured was Z-Glass Natural Transparent. After
manufacturing, the wing sections for the right half-plane [Fig. 6(a)],
the following steps consisted of manufacturing the sections for the
left half-plane. The process was identical, going through the same
steps as in the case of the right half-plane. The control elements (ailerons and flaps) were printed using Z-Glass Blue material. Each of
these elements was sectioned into two equal halves in order to fit the
printer’s volume. The ailerons were divided into two equal sections
of 125 mm, and the flaps were divided into two equal sections of
150 mm [Fig. 6(b)]. The next manufactured elements, which are part
of the wing, were the wing tips. These have the role of reducing the
induced drag at the wing tip of the aircraft and are provided with
fittings for mounting light-emitting diode (LED) navigation lights
[Fig. 6(c)]. The next component of the wing manufacturing process
was the central component, which has the role of joining the two
half-planes. This part was made from Z-PLA Pro and has stiffening
ribs to create high strength because this section connects the two
half-planes and the fuselage [Fig. 6(d)].
Manufacturing of the Empennage
Due to the size of the horizontal empennage, it was divided into
two components to fit the maximum print height. The vertical fin
needed additional support material in order to manufacture its suspended part [Fig. 7(a)]. The material used in the manufacture of the
empennage was Z-Glass Natural Transparent.
Manufacturing of the Landing Gear
The last parts of the aircraft’s composition that were 3D-printed
were the arms of the landing gear. The landing gear consists of
the two main arms and the front arm [Fig. 7(b)]. The manufacturing
parameters for the landing gear were Z-Glass Blue material with
0.14-mm layer thickness and 90% infill density (for higher resistance to ground impact).
Table 3 describes the weight of the components of the UAV
model and their manufacturing time.
The UAV presented a greater weight compared with UAV models produced from conventional structures (wood and composite
materials) because the fuselage and wing shells were manufactured
with a thickness of 1 mm. Normally, the minimum layer thickness
achievable is equal to twice the diameter of the nozzle, but the
Zortrax M200 Plus Printer has not manufactured components with
a thickness of less than 1 mm for selected materials (Z-PLA Pro and
Z-Glass). This limitation of the thickness of the deposition layer
resulted an increased weight of the UAV model components (wing,
fuselage, empennages, and landing gear) and a shorter flight time,
compared with the existing UAV models made from conventional
materials (wood and composite materials).
Assembly and Testing of the UAV Model
Assembly of the Manufactured Components and
Electronic Devices
The UAV model was assembled in parts: empennage, fuselage,
landing gear, and wing. The assembly of the components was done
by adhesion using a medium-density cyanoacrylate adhesive used
Fig. 5. Fuselage manufacturing process: (a) 3D-printed fuselage Sections 1 and 2; and (b) plate for fixing the servomechanisms and the Section 5 of
the fuselage.
© ASCE
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Fig. 6. Manufacturing process of the wing: (a) left half-plane of the 3D-printed wing; (b) flaps and ailerons ready for manufacture; (c) manufactured
wing tips; and (d) central component of the wing.
Fig. 7. Manufacturing process of the components of the UAV model: (a) empennage; and (b) arms of the landing gear.
Table 3. Weight of the 3D-printed components of the UAV model
Component
Fuselage
Wing þ ailerons þ flaps þ wing tips
Empennages
Landing gears
Total
Weight (g)
Manufacturing
time (h)
420
870
265
165
1,720
104
80
28
14
226
for bonding plastics. In the first stage, the assembly of the empennage was performed. In the assembly process, a square carbon
spar was used for stiffening. After the insertion of the spar through
the grooves of the ribs of the components, the components were
© ASCE
glued using adhesive. The elevator was attached using fiberglassreinforced adhesive tape to secure the fixing, but also to allow
it to move in the contact area with the empennage [Fig. 8(a)].
The movable part was attached to the fin and for the direction,
fiberglass-reinforced adhesive tape was used. Inside, Section 3
of the fuselage was mounted a plate on which two servomechanisms were attached. These servomechanisms have the role of performing the movement of the elevator and rudder in order to change
the direction of the flight. The servomechanisms were connected
to the receiver and are controlled using radio control. The section
covering the engine was assembled using screws for access and
interventions in the engine area. The engine was fixed to the panel
Section 5 using four screws fixed by nuts located inside the
fuselage.
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Fig. 8. Process of assembling the components of the UAV model: (a) empennage; (b) fuselage–empennage; (c) connection between the servomechanism lever and flap lever; and (d) central component of the structure of the wing.
After the fuselage was assembled, the horizontal and vertical
empennage was mounted in the tail area. The empennage was inserted into the specially designed areas for their mounting on the
fuselage [Fig. 8(b)]. The servomechanisms of the elevator and rudder were connected by means of two control rods connecting the
servomechanism lever and component lever. In order to assemble
the wing, four servomechanisms were installed inside the sections,
two servomechanisms actuating the ailerons and two servomechanisms actuating the flaps. The transmission of the motion from the
servomechanisms to the ailerons and flaps was achieved by coupling two flange yokes connected by means of a screw spindle
[Fig. 8(c)]. After assembling the wing sections and carbon-fiber
spars, the next step was to add the flaps and ailerons. The next
activity consists of the assembly of the two half-planes with the
central component [Fig. 8(d)].
For stiffening the landing gear, a 3-mm steel rod was installed
inside each arm. The wheels have a diameter of 40 mm and width
of 12 mm. The landing gear assembly on the fuselage was made
by screw-nut assembly, each arm being provided with two screws
[Fig. 9(a)]. The electronic components used in the UAV model
were the electric engine, speed regulator used to adjust the engine’s
operating speed, the servomechanisms used to drive the control
surface, and the aircraft control system, consisting of the radio
control, receiver, and the batteries used to power the radio control.
Fig. 9. Components of the UAV model: (a) landing gear; (b) electric engine; (c) Arduino Nano module; and (d) UAV model ready for flights.
© ASCE
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Fig. 10. Testing the UAV model: (a) ground; and (b) in-flight.
The electric engine [Fig. 9(b)] that was used is a brushless motor
with a diameter of 28 mm, length of 38 mm, and weight of 85 g,
and it can develop a maximum power of 745 W.
The propeller used for this engine has the dimensions of
254 × 127 mm. The regulator that was used has a capacity of 60 A
and weighs 53 g. It offers very smooth speed control, perfect linearity, and very fast response to the operation of the radio control
stick. The regulator also supplies the receiver with a voltage of 5 V.
This power supply to the receiver is necessary in order for it to able
to receive the signal transmitted by the radio control and to power
the servomechanisms. The battery that was used is lithium-polymer
type with a capacity of 1.8 A and voltage of 14.8 V. As a safety
measure against accidental start up as well as for powering electronic components without detaching the wing, a switch was installed in the bottom area of the fuselage. The speed controller
and servomechanisms are connected to a receiver. This receiver receives the signal transmitted by the radio control and transmits the
signal to the servomechanisms to perform a certain movement or
to the engine to change its speed. Each set of servomechanisms of
a control surface is connected to one of the receiver channels to
perform individual motions as follows: Channel 1 for ailerons,
Channel 2 for the elevator, Channel 3 for the engine, Channel 4
for the rudder, Channel 5 for the flaps, and Channel 6 to power
the Arduino Nano module [Fig. 9(c)]. The radio control operates
at a frequency of 2.4 GHz, the operating voltage is less than 80 mA,
and the supply voltage varies between 4.8 and 18 V. The radio control was powered by a 11.1 V. Li-Po battery. After the assembly and
connection of all the electronic components, the assembly process
of the UAV model [Fig. 9(d)] was successfully completed.
After the position of center of gravity (CG) was calculated
using an online calculator (Aircraft Center of Gravity Calculator–
RCplanes 2018) based on the configuration of the wing and
stabilizer, the UAV model was placed on a stand with two poles.
Considering the results of the calculation of the center of gravity,
the UAV model had to be balanced as follows: lead was added inside the nose cone of the UAV model to compensate for the weight
of the tail and get the CG closer to the leading edge of wing.
Ground and In-Flight Testing of the UAV Model
Several test flights were conducted in order to determine the aerodynamic characteristics of the UAV model. For the flight tests, it
was necessary to choose an asphalted site [Fig. 10(a)] due to the
small dimensions of the UAV model and the wheels of the landing
gear. Several taxiing preflights were conducted in order to determine the UAV model’s tendency to maintain the running direction.
The aircraft maintained the running direction even though it has no
steered wheels.
The flights of the UAV model were successfully completed,
carrying out all the stages (running, take-off, cruise flight, turn,
© ASCE
descent, and landing) in safe conditions and with maximum maneuverability, having a take-off weight of 2,200 g [Fig. 10(b)] and an
autonomy of 10 min. The motion amplitude of the control surfaces
was reduced to make the aircraft easier to control by the pilot. Due
to the high weight of the aircraft, a high enough flight speed had to
be ensured to avoid losing and gaining lift.
The following conclusions can be drawn from the flight tests of
UAV model: (1) the UAV model is stable and the center of gravity
position is right for stability; (2) there is a wide airspeed range
available, and stall characteristics are good and predictable, without
tendencies for unexpected spins of UAV model; and (3) the power
system of UAV model is rated high enough to sustain the desired
climb rate.
Conclusions
FDM, one of the processes of additive manufacturing technology, is
a highly researched manufacturing method that has made great
technological advances in the recent years. It can be remarked that
FDM technology is used to manufacture UAV models due to its
ability to print 3D high-strength materials. Nevertheless, due to
the limited volume of printing by FDM technology, the structure
(wing, fuselage, and empennage) of the UAV model from this paper
were mostly printed in modular parts and later connected using carbon rods to enhance the stiffness. The manufacture of UAV models
by AM technologies for the purpose of testing them in wind tunnels
or in-flight is very efficient and can be done in a short time, having
as advantages the simplicity of the manufacturing and assembly
process, but also the removal of the costs for the molds if they were
made of composite materials.
The flight model that has been designed and manufactured is a
clear proof that an UAV can be manufactured almost completely
using FDM technologies, and it can fly and operate with good aerodynamic characteristics and high maneuverability. Also, aviation
companies will be able to quickly manufacture and test airplanes
on a certain scale, even from the prototype stage, which will allow
the optimization of the constructive and aerodynamic solutions in
order to improve the flight performances. In conclusion, the design,
development, aerodynamic analysis, and the manufacture of UAV
models with good aerodynamic and flight characteristics can be
performed by using FDM technology in order to manufacture their
components.
Data Availability Statement
All data, models, and code generated or used during the study appear in the published article.
06020002-8
J. Aerosp. Eng., 2020, 33(4): 06020002
J. Aerosp. Eng.
Acknowledgments
This work was financially supported by the Transilvania University
of Brasov.
Downloaded from ascelibrary.org by Western Sydney University Library on 05/16/20. Copyright ASCE. For personal use only; all rights reserved.
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