The first step in our project was selecting the most suitable airfoil, a crucial choice that impacts aerodynamic performance, lift, and stability. After extensive research, we chose the NACA 2415 airfoil, which has a 2% camber at 40% chord and 15% maximum thickness. This profile offers a balanced lift-to-drag ratio and stability, ideal for our educational model aircraft. We then designed the wing structure using scaled dimensions based on the NACA 2415, ensuring aerodynamic accuracy. CNC-cutting was used to precisely replicate the airfoil in the wing components. This foundational decision guided the development of the wings, ailerons, and overall aerodynamics, ensuring structural soundness and effective demonstration of flight principles.

The second step in our project was cutting seven airfoil sections using a CNC machine to ensure precise dimensions for our swept-back wing design. Since the wing required varying airfoil sizes for proper shape and performance, we first created scaled CAD models that accounted for the sweep angle and alignment. Once finalized, the designs were CNC-cut with high accuracy, producing smooth, consistent, and symmetrical sections. This precision was essential for achieving the correct wing sweep, which enhances aerodynamic efficiency, reduces drag, and improves high-speed stability—mirroring real aircraft performance. This step was critical in laying the foundation for accurate wing assembly and optimal flight characteristics.

The third step in our project was determining the correct spacing between each airfoil section to ensure structural integrity and aerodynamic efficiency. Precise measurements and calculations were needed, as spacing impacts wing strength and airflow distribution. After multiple adjustments, we finalized a 2-inch gap between sections, maintaining the consistency of the swept-back design.

To aid assembly, we sketched the full wing layout on a flat surface, creating a detailed reference to align each airfoil accurately and maintain uniform spacing. This step was crucial for building a structurally sound, aerodynamically efficient wing, preparing us for the next construction phases.

The fourth step in our project was drilling precise holes into each airfoil to insert support sticks, ensuring structural integrity and proper wing alignment. Using exact measurements, we marked and drilled consistent holes with a drill press to prevent misalignment.

With the support structure in place, we constructed and integrated the flaps and ailerons—key control surfaces for lift and roll control. We carefully cut, shaped, and sanded them to fit the wing design, ensuring smooth movement. After fitting them securely, we confirmed they moved freely, bringing us closer to a fully functional, flight-simulating wing.

In the final step, we secured all components by gluing each airfoil and support stick to ensure the wing remained rigid and stable. Precise alignment and strong adhesive were critical for maintaining aerodynamic performance and structural durability. After allowing sufficient drying time, we constructed the wing box to firmly hold both wings in place.

The wing box was carefully measured, cut, and aligned to ensure a perfect fit and strong connection. We tested and adjusted the wing fit to guarantee stability under load. With this step complete, the wing was fully assembled and ready for integration with the fuselage—marking a major milestone in our aircraft's construction.

As part of our continued efforts to improve our wing model, we implemented several key enhancements aimed at both performance simulation and educational value. One of the most significant changes was the redesign and extension of the flaps. In the previous version, the flaps were noticeably undersized, limiting their ability to realistically demonstrate how control surfaces affect lift and drag. After reviewing the performance and structure of the original design, we decided to increase the flap length to ensure better coverage and improved control surface area, more accurately reflecting the proportions found in real aircraft wings.

To construct the new flaps, we used the same successful technique previously applied to our ailerons. This involved carefully cutting and shaping the last segments of the airfoil ribs, aligning them precisely, and bonding them together using strong adhesive. The result is a set of flaps that are not only structurally sound but also consistent in profile and alignment with the rest of the wing. For additional realism and strength, we chose to cover the flaps with a thin sheet of metal. This not only gives the control surfaces a smooth, aerodynamic finish but also protects the internal structure and adds a layer of authenticity to the model. The metal sheet also allows for clearer visual distinction between the flaps and other parts of the wing.

We also made improvements to the wing's leading edge, which is a critical area for managing airflow and reducing turbulence. To better simulate the aerodynamic shape of a real aircraft wing, we covered the leading edge with a very thin sheet of wood. This material was carefully selected for its flexibility and ease of shaping, allowing us to maintain a smooth, continuous curve along the front of the wing. This addition enhances the aerodynamic profile and creates a more professional, realistic appearance. It also allows air to flow smoothly over the top of the wing, which is essential for generating lift.

Another important modification was made to the wing box. We resized the wing box to ensure a proper fit with the fuselage, as the dimensions of the wing box now depend directly on the size of the fuselage. To achieve a seamless connection, we filled the sides to make the transition between the wing box and fuselage straight and flush. This adjustment improves both structural integration and the visual alignment between the wing and the main body of the aircraft.

At the same time, we deliberately chose to leave the trailing edge of the wing uncovered. This decision was made to serve an educational purpose. By exposing the internal structure—such as the ribs, spars, and internal reinforcements—students and viewers can clearly observe how the wing is constructed from the inside out. This open section transforms the wing into both a functional aerodynamic model and a valuable teaching aid. It provides insight into the relationships between the airfoil shape, internal supports, and outer skin, helping learners visualize how form and function are integrated in aircraft design.

Overall, these modifications to the wing—longer flaps with metallic coverings, a properly contoured leading edge with wood sheathing, a resized and better-integrated wing box, and an open trailing edge—result in a more accurate, functional, and educational model. These enhancements not only improve aerodynamic behavior but also provide an excellent opportunity for hands-on learning and deeper understanding of aircraft wing construction and control surface design.

To effectively demonstrate the movement of both primary and secondary flight controls on our model aircraft, we focused on accurately replicating real-world control surface behavior. Our primary objective was to ensure that the model realistically simulates how actual aircraft components function in operation. After exploring various mechanical options, our initial idea was to use servo motors and linear actuators. Following extensive research and comparison with full-scale aircraft systems, we concluded that this combination is the most practical and accurate method for achieving realistic motion in a model setting.

To bring this concept to life, we will be utilizing servo motors to control the movement of the primary flight control surfaces, including the ailerons, horizontal stabilizer (elevator), and vertical stabilizer (rudder). These components are essential for roll, pitch, and yaw control respectively. For the secondary flight control system, we chose to use a linear actuator to operate the wing flaps, which require more linear motion to mimic their function of increasing lift during takeoff and landing.

All actuators and servo motors will be integrated and controlled through an Arduino Uno microcontroller. We will program the Arduino using C++ to precisely control the timing, angle, and speed of each surface's movement based on input commands or pre-programmed sequences. This approach not only enhances the educational value of the model but also closely mirrors the electromechanical principles used in modern aircraft, making our project both technically accurate and highly functional.

Wiring Connections Between Arduino, Potentiometer, and Servo Motor

Initially, we had little to no knowledge about how to connect the components of our control system—namely the potentiometers and servo motors—to the Arduino. However, after conducting extensive research and consulting with our instructors, we were able to understand the correct wiring process and successfully implement it.

The first step was connecting the potentiometer to the Arduino. A potentiometer has three pins: one for power (VCC), one for ground (GND), and one for the signal (wiper). We connected the signal (middle) pin of the potentiometer to analog input pin A0 on the Arduino. The ground pin was connected to one of the Arduino's GND ports, and the power pin was connected to the 5V output pin on the Arduino. This setup allows the potentiometer to send varying voltage values (between 0V and 5V) to the Arduino based on the position of the dial, which we can read in our code to determine the desired control surface angle.

Next, we connected the servo motor. Servo motors typically have three wires as well: power (VCC), ground (GND), and signal (PWM control). The power wire was connected to the same 5V output as the potentiometer, and the ground wire was connected to the GND port to complete the circuit. The signal/control wire of the servo was connected to digital pin 3 on the Arduino, which is capable of sending Pulse Width Modulation (PWM) signals.

With this configuration, the Arduino reads the analog value from the potentiometer and maps it to a corresponding angle, which it then sends to the servo motor through the PWM pin. As a result, rotating the potentiometer causes the servo to move proportionally to the angle input, allowing us to simulate the deflection of control surfaces like ailerons, elevators, or rudders.

This wiring setup became the foundational model for connecting additional servo motors and potentiometers, enabling us to control multiple flight surfaces independently through our custom-built control panel.

Wiring Connections Between Arduino and Linear Actuator

Just like with the servo motors and potentiometers, we initially lacked the knowledge to properly connect the linear actuator to our Arduino system. After further research and guidance from our instructors, we were able to fully understand and implement the correct wiring setup.

A linear actuator, especially one with simple two-wire DC operation, works differently from a servo motor. To control its motion (extend or retract), we need to control the direction of current flow. This cannot be done directly with the Arduino alone. Therefore, we used an H-bridge motor driver module (such as the L298N or L9110S), which allows us to control both the direction and speed of the actuator using signals from the Arduino.

Here’s how we connected it:

Power Supply: Since linear actuators typically require more current than the Arduino can provide, we connected an external 12V DC power supply to the motor driver’s power input (marked as +12V or Vcc) and its ground to the common GND shared with the Arduino.