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Project Quiver PT1 Engineering Report

Authors21stCenturyAlex, alperenag, errrks.eth, Julius, Dow Fisher KBM, ZeynepB
Editorerrrks.eth
DateApril 2025

PT1 Hero

1. Introduction​

The purpose of Project Quiver is to design and manufacture a practical multi-purpose multi-rotor unmanned aerial vehicle. This aligns with Arrow’s mission of developing manned and unmanned aircraft for the commercial aviation market while generating new concepts in manufacturing, materials science, structural design, and related technologies. Equipped with internet native collaborators and Web3 infrastructure, Arrow aims to break up the lack of innovation in the global drone market.

This aircraft is designed to perform typical light UAV missions. The design concept is: compact and portable, easy to manufacture, easy to maintain, highly reliable, highly adaptable, and expandable.

The First Prototype (PT1) of Project Quiver will feature:

  • A common quadcopter layout to ensure energy efficiency and simplified structure.
  • Maximum mission load of 25 kg. Considering the safety factor, the designated maximum thrust force is about 45 to 50 kg.
  • Foldable motor beams and propellers for ease of storage and transportation.
  • Standardized quick-release mission equipment pylon (Attachment interface).
  • Digital autopilot system assisted features, such as GNSS-assist hovering, waypoint missions, radar altimeter, etc.
  • FPV camera with video transmission to assist pilot decision and various mission actions.
  • Powered with 14-cell LiHV smart battery and advanced main power connectors commonly used by heavy drones.
  • CAN bus for signal communication to avoid electromagnetic interference that traditional non-differential signals such as PWM may be subject to.
  • Using digitalized sensor communication to monitor more components, such as battery cell temperature and ESC temperature.
  • Using integrated thrust terminal to improve the reliability and design convenience of the thrust system, also for easier sourcing, installing and initial testing.
  • single source, fully integrated motor arm with propulsion system for easier sourcing, installation, and testing.
  • Implement testbed PDB and contactor from Project Feather for safe operation of the power distribution system.

Based on these characteristics, Project Quiver will also compete with other UAVs in the market in terms of parameters such as endurance, empty weight ratio, open source development, and mission equipment. It's also expected to gradually introduce more advanced designs including but not limited to the following items in future prototypes: The following features will be introduced in future prototypes:

  • Real-Time Kinematic (RTK) high-precision GNSS positioning
  • Dedicated PDB
  • Custom battery pack
  • Custom ESC
  • Integrated 3D printed structure
  • Hazard protect airframe
  • Multiple mission attachment interfaces
  • Retractable landing gear
  • Emergency ballistic parachute
  • LiDAR navigation
  • Dedicated ground control software
  • etc.

PT1 is neither water nor dustproof and includes a single standardized attachment interface on the cockpit’s underside. The flight controller unit (FCU) remains exposed atop the battery enclosure for simplicity.

The initial mission equipment, a standardized quick-release "Brush Pod" herbicide dispenser, is designed for commercial aerial vegetation management.

Project Quiver utilized Onshape and Fusion 360 for structural design, layout, and finite element analysis (FEA). Flexible software selection enabled team members to leverage their preferred tools and workflows, facilitating interoperability through STEP and similar formats.

2. Project Requirements

2.1 Flight-Critical Systems​

Project Quiver PT1 must incorporate robust and reliable flight-critical systems to ensure safe and predictable flight performance. The UAV shall feature advanced flight-control electronics that maintain stable operation under varying flight conditions and payload configurations. These systems will prioritize redundancy, allowing the drone to safely land even if certain critical components fail during flight operations.

Flight Controller:​

The aircraft SHALL be equipped with a Pixhawk flight controller.

GPS Module:​

The aircraft SHALL have redundant high-accuracy GPS antennas to support reliable navigation.

Radar Altimeter:​

The aircraft SHALL include a radar altimeter for precise altitude measurements, particularly during low-altitude operations.

Telemetry:​

The aircraft SHALL support real-time telemetry data transmission with a range of 5 km.

Motors:​

The aircraft’s motors SHALL be capable of providing sufficient thrust to maintain hover with full payload between 50% - 60% throttle.

Propellers:​

  • The propellers SHALL be large and efficient to maximize lift and minimize power consumption.

  • The propellers SHOULD be foldable, if feasible, to support ease of storage and transport.

ESCs:​

The aircraft’s ESCs SHALL be compatible with a up to a 14S power supply, integrate with the CAN bus for precise motor control, and provide sufficient current to meet motor requirements.

2.2 Structural Integrity and Components​

The structural frame shall leverage commercially available, off-the-shelf, or easily manufacturable components to enable rapid assembly and ease of replacement. The chosen materials must be lightweight yet strong enough to sustain heavy lift operations, accommodating considerable payload capacities without compromising durability or structural safety. Additionally, the structural configuration must allow flexibility for modifications and additions in future iterations.

Airframe:​

The aircraft SHALL incorporate a durable carbon fiber or aluminum frame capable of supporting a maximum take-off weight (MTOW) of 25 kg and SHALL be designed to accommodate various payload configurations.

The airframe SHALL be constructed using:

  • Commonly available off-the-shelf components

  • Common material processing methods.

The aircraft’s motor arms SHALL be foldable to enhance portability and ease of deployment.

Landing Gear:​

The aircraft’s landing gear SHALL be shock-absorbing and support the full MTOW during landing, including in hard-landing scenarios

Modular Design:​

The aircraft SHALL be designed with modular, easily replaceable arms, motors, and ESCs to facilitate streamlined maintenance.

2.3 Electrical Systems and Power Management​

A simplified and robust electrical system shall be designed, ensuring reliability and ease of troubleshooting. Commercially available battery packs must support adequate flight durations, providing sufficient power for continuous flight under maximum payload conditions. The power system should include protective features such as circuit breakers or fuses, mitigating the risk of electrical overload or failures.

Battery:​

The aircraft SHALL use a 12S or 14S LiPo or Li-ion battery with sufficient capacity to meet endurance requirements.

Battery Management System (BMS):​

The BMS SHALL monitor battery health, temperature, and charge/discharge rates to ensure optimal battery performance and safety.

HV Kill Switch:​

The aircraft SHALL have a kill switch for the high-voltage electrical network.

LV Kill Switch:​

The aircraft SHALL have a kill switch for the low-voltage electrical network.

Power Distribution Board (PDB):​

The PDB SHALL provide stable 12S or 14S power distribution to all critical components.

Battery Case:​

The battery SHALL be housed in a case permitting easy swap for rapid replacement in the field.

Charging:​

The aircraft SHALL NOT require in-aircraft battery charging capabilities.

Hover Time Without Payload:​

The aircraft SHALL provide at least 25 minutes of hover endurance without payload.

Battery Reserve:​

The aircraft SHALL ensure a 20% battery reserve upon landing for safety considerations.

Cooling System:​

The aircraft SHALL incorporate an effective cooling system for motors, ESCs, and the battery, if necessary, to maintain consistent performance during prolonged flights.

Health Monitoring:​

The aircraft SHALL provide real-time monitoring of ESC and battery health.

Pre-Flight Diagnostics:​

The aircraft SHALL include a pre-flight diagnostics system to battery levels, GPS accuracy, radar altimeter functionality, and sensor health before each flight.

Heading Indicator LEDs:​

The aircraft SHALL include LEDs with predefined colors around it to indicate its direction.

2.4 Payload Integration and Imaging​

The UAV prototype shall integrate a stabilized camera system mounted on a gimbal, providing steady, high-quality video feeds to ground operators. An adaptable payload attachment mechanism must enable rapid payload swaps in-field, thus maximizing versatility across various mission profiles.

Payload Capacity:​

The aircraft SHALL be capable of carrying at least 7 kg of payload during any mission.

Quick-Release Mounting:​

The payload attachment system SHALL incorporate a modular quick-release mechanism, allowing for the attachment of various payloads with minimal setup time.

CAN Integration:​

The payload system SHALL support CAN bus integration to facilitate seamless data communication between the payload and the flight controller.

12V Power Feed:​

The aircraft SHALL provide a dedicated 12V power line for powering payloads, adaptable to a variety of equipment.

Front-Facing Camera:​

The aircraft SHALL be equipped with a fixed front-facing camera for navigation or visual feedback.

Down-Facing Camera:​

The aircraft SHALL include a fixed downward-facing camera for mission support and landing assistance.

Video Telemetry Range:​

The video telemetry SHALL have 1 km of range.

2.5 Flight Testing and Verification​

A comprehensive testing program is required for PT1, verifying core flight performance, structural strength, electrical reliability, and payload handling capabilities. Testing should document essential parameters and establish baseline operational limits, providing valuable data to inform subsequent design iterations.

2.6 Regulatory Compliance​

PT1, and all subsequent Quiver systems shall be built to comply with CFR Part 107 Small Unmanned Aircraft Systems standards and requirements.

3. Prototype Specifications

3.1 Flight-Critical Systems​

  • Flight Controller: Utilizes a Pixhawk 6X flight management System, precision navigation, and autonomous flight modes. Must include redundancy across critical sensors (IMU, GPS, barometer).

  • Navigation Sensors: Include dual GNSS modules, providing high accuracy positioning with the possibility of extension to Real-Time Kinematics (RTK) support to facilitate precise waypoint navigation and payload delivery.

3.2 Structure and Geometry​

  • Frame Material: Employ carbon fiber tubes interconnected with aluminum joints for strength-to-weight optimization. The frame configuration shall be aluminum plating able to accommodate interchangeable arm sections to simplify repairs and upgrades.

  • Maximum Takeoff Weight (MTOW): Prototype must support a total weight exceeding 25 kg.

  • Payload Capacity: Minimum payload capability of 10 kg is required to validate heavy-lift capabilities.

  • Structural Safety Factor: Structural integrity must ensure a safety factor of at least 2.5 times the maximum anticipated operational loads.

3.3 Propulsion and Power​

  • Motors and ESCs: Select commercial-grade brushless DC motors rated for 12S to 14S battery configurations, paired with ESCs capable of sustaining at least 80A continuous current, ensuring sufficient thrust-to-weight performance.

  • Battery System: LiPo or Li-Ion battery packs rated at 12S or 14S voltage levels must guarantee a minimum of 20 minutes endurance under fully loaded conditions.

  • Propellers: Integrate foldable carbon-fiber propellers optimized specifically for heavy-lift efficiency, minimizing noise and maximizing flight endurance.

3.4 Electrical Systems​

  • Electrical Layout: Wiring harnesses shall be modular and clearly labeled for ease of maintenance and fault isolation. All wiring must be heat-resistant and abrasion-resistant to withstand harsh operational environments.

  • Power Distribution: Install dedicated circuit switches to protect critical flight electronics and payload circuits from potential short circuits or electrical surges.

3.5 Payload Handling and Camera​

  • Gimbal System: Implement a 3-axis stabilized gimbal, providing precise control of camera orientation to deliver steady footage even in turbulent flight conditions.

  • Camera Capabilities: Equip PT1 with a camera capable of delivering at least 1080p resolution at 30fps, streaming live footage directly to the ground control system with minimal latency.

  • Payload Attachment Interface: Establish a quick-release payload rail system with adjustable balance points, enabling secure payload attachment and easy in-field interchangeability.

3.6 Flight Control and Telemetry​

  • Communication Systems: Employ telemetry links capable of maintaining reliable communication over distances of at least 2 km, utilizing 900 MHz or 2.4 GHz bands, backed by a redundant 433 MHz communication link as a fallback option.

  • Ground Control Station (GCS): Real-time telemetry data, including flight parameters, payload conditions, and battery health, must be continuously transmitted to the operator’s interface.

3.7 Environmental and Operational Specifications​

  • Operating Temperature: The drone shall reliably operate in a temperature range from -10°C to +45°C, enabling effective use in diverse environmental conditions.

  • Wind and Moisture Resistance: Prototype must maintain stable flight control in wind speeds up to 25 km/h and include basic splash-resistant protection for electrical and propulsion systems, protecting against incidental moisture exposure.

3.8 Maintenance, Assembly, and Documentation​

  • Assembly Instructions: BOMs and detailed assembly instructions should be created and provided.

  • Assembly Efficiency: Assembly of the UAV, including installation of payloads and batteries, shall be achievable within 60 minutes by trained personnel from packaged state.

  • Maintenance Schedule: A clear and concise maintenance manual detailing procedures and inspection intervals must be provided.

3.9 Flight Testing and Validation​

  • Initial Flight Tests: Conduct controlled test flights covering hover stability, maneuverability, payload management, and endurance under realistic operational scenarios. All results and incidents should be carefully documented.

  • Documentation: Provide comprehensive documentation, including flight logs, inspection reports, photographic and video evidence of successful testing outcomes, ensuring traceability of performance improvements for future iterations.

4. Mission Performance

Below is a mission performance analysis of maximum possible flight time for two missions: Surveillance and Waypoint Missions both under a Tattu 3.5 14S LiHV 30 Ah battery.

Key assumptions:

  • Usable Battery: 21.6 Ah (after 2C derating to ~27 Ah, then a 20% reserve).
  • Propulsion: 4 Hobbywing X6 Plus motors.
  • Mission Legs: short, fixed‐time take‐off, climb, descent, landing; the remaining time is the main mission leg.
  • Real-World Effects: Climb rates, aerodynamic efficiency, battery health, and environmental conditions do not affect the performance.

4.1. Surveillance Mission​

In this mission, the aircraft hovers with 20 kg MTOW without any payload, using its camera for surveillance.

4.1.1. Current Requirements​

  • Hover Current (20 kg): ~40.9 A (estimated from thrust‐vs‐current data of Hobbywing X6 Plus).
  • Take‐Off / Climb (110%): ~48.6 A
  • Descent (90%): ~35.5 A
  • Landing (100%): ~40.9 A

4.1.2. Mission Leg Times​

  • Take‐off: 0.5 min
  • Climb: 1.5 min
  • Descent: 1.0 min
  • Landing: 1.0 min

Convert each to hours and multiply by current to get amp‐hours.

  1. Take‐off (0.5 min)

    • 0.5 min = 0.0083 hr
    • 48.6 A × 0.0083 hr ≈ 0.40 Ah

  2. Climb (1.5 min)

    • 1.5 min = 0.025 hr
    • 48.6 A × 0.025 hr = 1.22 Ah

  3. Descent (1.0 min)

    • 1.0 min = 0.0167 hr
    • 35.5 A × 0.0167 hr ≈ 0.59 Ah

  4. Landing (1.0 min)

    • 1.0 min = 0.0167 hr
    • 40.9 A × 0.0167 hr ≈ 0.68 Ah

Sum of non‐mission legs = 2.89 Ah.

4.1.3. Maximum Hover Duration​

Remaining capacity for hover = 21.6 Ah − 2.89 Ah = 18.71 Ah.
At 40.9 A (hover), available hover time = 18.71 Ah ÷ 40.9 A ≈ 0.457 hr = ~27.4 min.

Total Surveillance Flight Time

  • Non‐mission legs: 0.5 + 1.5 + 1.0 + 1.0 = 4.0 min
  • Hover: ~27.4 min
  • Overall: ~31.4 min

4.2. Waypoint Mission​

In this mission, the aircraft travels with 25 kg MTOW between waypoints. The power consumption for forward flight is assumed as 120% of hover.

4.2.1. Current Requirements​

  • Hover Current (25 kg): ~57.5 A
  • Forward Flight (120%): ~69 A
  • Take‐Off/Climb (110%): ~66.5 A
  • Descent (90%): ~49.9 A
  • Landing (100%): ~57.5 A

4.2.2. Mission Leg Times​

  • Take‐off: 1.0 min
  • Climb: 2.0 min
  • Descent: 1.0 min
  • Landing: 1.0 min

  1. Take‐off (1.0 min)

    • 1.0 min = 0.0167 hr
    • 66.5 A × 0.0167 hr ≈ 1.11 Ah

  2. Climb (2.0 min)

    • 2.0 min = 0.0333 hr
    • 66.5 A × 0.0333 hr ≈ 2.22 Ah

  3. Descent (1.0 min)

    • 1.0 min = 0.0167 hr
    • 49.9 A × 0.0167 hr ≈ 0.83 Ah

  4. Landing (1.0 min)

    • 1.0 min = 0.0167 hr
    • 57.5 A × 0.0167 hr ≈ 0.96 Ah

Sum of these legs = 5.12 Ah.

4.2.3. Maximum Forward‐Flight Duration​

Remaining capacity for forward flight = 21.6 Ah − 5.12 Ah = 16.48 Ah.
At 69 A, flight time = 16.48 Ah ÷ 69 A ≈ 0.239 hr = ~14.3 min.

Total Loiter Flight Time

  • Non‐mission legs: 1.0 + 2.0 + 1.0 + 1.0 = 5.0 min
  • Forward flight: ~14.3 min
  • Overall: ~19.3 min

4.3. Summary​

Under ideal conditions, Project Quiver PT1 achieves a total flight time of approximately 31.4 minutes for surveillance missions at 20 kg MTOW, including about 27.4 minutes of hover. For waypoint missions at the full 25 kg MTOW, total flight time is around 19.3 minutes, with roughly 14.3 minutes of forward flight. Both mission scenarios incorporate a 20% battery reserve to ensure operational safety. Actual performance may vary due to environmental conditions and operational factors.

5. Flight Mechanics

This section presents the flight mechanics analysis of Project Quiver, with a focus on assessing its dynamic behavior, stability characteristics, and control performance under operational loading conditions. The aircraft has a maximum MTOW of 25 kg, and two critical configurations were evaluated:

  • No Payload Configuration (18 kg): Vehicle equipped with propulsion system, avionics, and battery, but without any payload modules.
  • With Brush Bullet Dispenser (22 kg): Includes a 4 kg payload module mounted at (0, 0, -40 cm) relative to the center of gravity, simulating an operational mission loadout.

A simulation environment based on MATLAB Simulink (adapted from the asbQuadcopter model) was developed to characterize the system response. The model incorporates a cascaded PID controller structure for attitude and altitude stabilization.

5.1 Static and Dynamic Stability Analysis​

5.1.1 Static Stability​

Static stability describes the initial tendency of the vehicle to return to equilibrium following a small disturbance.

  • Center of Gravity (CG) Effects:

    • In the no payload configuration, the CG is closely aligned with the vehicle’s geometric center, resulting in neutral static stability in roll and pitch.
    • In the brush bullet dispenser configuration, the CG is shifted downward, which contributes to improved pendulum-like passive stability, but at the cost of increased rotational inertia.

  • Static Margin:

    • The vertical CG offset in the payload configuration increases the static margin, enhancing stability in hover but reducing control responsiveness.

5.1.2 Dynamic Stability​

Dynamic stability pertains to the time-dependent response of the system to disturbances.

  • Eigenvalue Analysis:

    • Both configurations exhibit eigenvalues with negative real parts, indicating asymptotic stability.
    • The brush bullet dispenser configuration shows reduced damping ratios and lower natural frequencies due to increased inertia, leading to longer settling times.

  • Estimated Damping Ratios (ζ):

    • No Payload: 0.65 – 0.8
    • With Brush Bullet Dispenser: 0.5 – 0.6

  • Time-to-Half (τₕ):

    • No Payload: 0.8 – 1.2 s
    • With Brush Bullet Dispenser: 1.4 – 1.8 s

  • Phugoid and Oscillatory Modes:

    • Both configurations exhibit mild phugoid-like modes due to coupling between pitch and vertical motion, with greater amplitude and period in the payload configuration.

5.2 Trim Analysis​

Trim conditions represent the steady-state control inputs required to maintain hover.

  • Hover Thrust per Motor:

    • No Payload: ~4.5 kgf/motor
    • With Brush Bullet Dispenser: ~5.5 kgf/motor

  • Trim Attitude Angles:

    • No Payload: < 0.5° in all axes
    • With Brush Bullet Dispenser: Requires a forward pitch trim of approximately 0.9° due to the CG offset

  • Power Margin:

    • No Payload: ~45% thrust reserve
    • With Brush Bullet Dispenser: ~30%, approaching the control authority limits under aggressive conditions

5.3 Control Response and Maneuverability​

System responsiveness was evaluated via step response analysis and control effort metrics.

5.3.1 Step Response Characteristics​

The actual control architecture and gains in Ardupilot were not replicated in the Simulink model, instead, a simplified cascaded PID controller was employed. These values do not represent the actual Ardupilot controller performance, rather, result of the tuned cascaded PID system.

  • Rise Time (10–90%):

    • No Payload: ~0.45 s
    • With Brush Bullet Dispenser: ~0.65 s

  • Settling Time (±2%):

    • No Payload: ~1.2 s
    • With Brush Bullet Dispenser: ~1.8 s

  • Overshoot:

    • No Payload: ~5%
    • With Brush Bullet Dispenser: ~12%

5.3.2 Control Effort and Authority​

  • Required Control Effort in Pitch Maneuvers:

    • No Payload: ~15% of available motor thrust
    • With Brush Bullet Dispenser: ~22%, increasing actuator workload

  • Motor Saturation Risk:

    • In the payload configuration, motor commands approach 85% of maximum thrust during aggressive inputs, reducing margin for disturbance rejection or emergency maneuvers

5.4 Lateral-Directional Stability​

  • Cross-Axis Coupling:

    • Slight increase in roll-yaw coupling observed in the brush bullet dispenser configuration due to the lower CG, but remains within controllable limits.

  • Spiral Mode and Longitudinal Coupling:

    • No divergent spiral or unstable longitudinal modes detected in either configuration.

5.5 Disturbance Rejection Performance​

5.5.1 Wind Gust Response (Lateral)​

  • Simulated Wind Input: Step disturbance of 5 m/s applied laterally
  • Recovery Time:
    • No Payload: ~1.5 s
    • With Brush Bullet Dispenser: ~3.2 s, with greater drift before correction

5.5.2 Vertical Gust Response​

  • Simulated Vertical Gust: ±2 m/s impulse
  • Altitude Excursion:
    • No Payload: ~15 cm
    • With Brush Bullet Dispenser: ~25 cm

5.6 Conclusions​

  • Both configurations exhibit stable dynamic behavior, but the payload configuration is slower to respond and more susceptible to disturbances due to increased mass and inertia.
  • The control authority in the payload configuration is significantly reduced, and motor saturation may occur under high-demand maneuvers.
  • Disturbance rejection performance is degraded in the payload configuration, requiring longer recovery times.
  • Hover and trim characteristics remain within acceptable ranges, but controller gains may require re-tuning for payload missions to improve damping and responsiveness.

6. Propulsion System

Based on the Quiver project specifications, the following manufacturers for electric motors, compatible propellers, and ESCs were evaluated.

Table 1. Drone Propulsion System Comparison for 25 kg MTOW​

FeatureSystem 1System 2System 3System 4System 5System 6
MotorMAD 6215 IPET-Motor P80Ⅲ PT-Motor P60MAD M6C12 EEEFreerchobby FRC HeavyHobbywing XRotor X6 Plus (integrated system)
Max Thrust11.5 kg16 kg8.5 kg9.4 kg11.5 kg11.822 kg
Voltage (V)44.4V (12S)44.4V (12-14S)44.4V (12-14S)44.4V (12-14S)48V (6S-12S)44.4V (12-14S)
Max Current (A)60A70A38A36.2A59.7A51.8A
Price (USD)$98$199.9$107.9$129$62$97
Weight (g)370 g649 g225 g257 g370 g710 g (integrated)
Recommended Propeller21-22"30-32"22"21-24"22"24"
Propeller Cost Estimation$28$45$28$28$28Included
Propeller Weight Estimation0.065 kg0.170 kg0.065 kg0.065 kg0.065 kgIncluded
ESCMAD AMPX 80A (5-14S) Drone ESCMAD AMPX 80A (5-14S) Drone ESCMAD AMPX 80A (5-14S) Drone ESCMAD AMPX 80A (5-14S) Drone ESCMAD AMPX 80A (5-14S) Drone ESCIncluded
ESC Cost$60$60$60$60$60Included
ESC Weight0.19 kg0.19 kg0.19 kg0.19 kg0.19 kgIncluded
System Thrust46 kg64 kg34 kg37.6 kg46 kg47.288 kg
System Weight2.5 kg4.035 kg1.92 kg2.048 kg2.5 kg2.84 kg
System Cost$744$1,219.6$783.6$868$600$388

The Hobbywing XRotor X6 Plus integrated propulsion system is selected as the best match for QUIVER propulsion requirements in terms of thrust, weight, and cost. Integrated propulsion systems combine a motor, ESC, and propeller into one optimized unit. This system offers the lowest cost compared to other evaluated options, with comparable weight. It includes power cables which can be trimmed to the necessary length. Advantages of an integrated system include optimized performance due to matched components, reduced electrical losses from shorter wiring, improved aerodynamics, and waterproof casing, significantly reducing installation workload.

Selected Battery​

The Tattu 14S HV 30000mAh Smart Battery is chosen for its integrated battery management system (BMS) and efficient mechanical integration. The battery connects to the drone through a specialized Molex connector, secured by a safety latch.

SpecificationDetails
Configuration14S1P (14 series, 1 parallel)
Nominal Capacity30,000 mAh (0.2C, 4.3-3.0V)
Minimum Shipping Voltage52.5 ~ 54.6V (3.75-3.9V per cell)
Nominal Voltage53.2V (3.8V per cell)
Internal Resistance9 ± 3.5 mΩ (1 kHz AC method)
Dimensions (H×W×L)MOLEX: 103 × 251 × 333 mm
Battery Weight11,200 ± 300 g
Charging ModeCC-CV (Constant Current – Constant Voltage)
Maximum Charging Voltage60.9V
Standard Charging Current6A (0.2C, ~450 min charge time)
Fast Charging Current150A (5C, ~18 min charge time)
Discharge Cut-off Voltage3.0V/cell @ 0.2C, 3.3V/cell @ ≥0.5C
Standard Discharge Current6A (0.2C, ~270 min discharge time)
Max Continuous Discharge Current180A (~9 min discharge time)
Peak Discharge Current220A (≤ 3s)

Table 2. QUIVER Propulsion System Configuration​

#PART DESCRIPTIONEQ DESIGNATIONWEIGHT (g)
1Hobbywing XRotor X6 Plus integrated propulsion systemMOTOR,PROP,ESC, LF710
2Hobbywing XRotor X6 Plus integrated propulsion systemMOTOR,PROP,ESC, RF710
3Hobbywing XRotor X6 Plus integrated propulsion systemMOTOR,PROP,ESC, LR710
4Hobbywing XRotor X6 Plus integrated propulsion systemMOTOR,PROP,ESC, RR710
5TATTU 14S HV 30000mAh Smart BatteryBATTERY, MAIN11250

##Propulsion System Mechanical Interfaces

The Hobbywing XRotor X6 Plus integrated propulsion system must be mounted on a 30 mm diameter tube, with cables routed internally. The system is secured using four included screws.

The battery connects via a specialized Molex connector, featuring a safety latch for secure, simplified installation.

Electrical Interfaces​

  • XT60 connector on motor wires
  • Specialized Molex connector on battery

Installation Requirements​

Follow manufacturer guidelines for secure mechanical mounting, correct internal cable routing, and proper electrical connections to ensure optimal system performance and safety.

7. Electrical System

This section provides a comprehensive overview of the electrical design and integration work carried out for the V1 prototype of Project Quiver. It details the planning, layout, and execution of the power and signal systems essential for the first iteration fo Project Quiver, which is engineered to deploy a brush bullet payload. The report outlines power and signal layouts, block diagrams, and wiring schematics, along with an in-depth review of the selected components—from battery systems and power distribution boards to flight controllers and ESCs. Finally, it covers critical considerations such as wiring methods, connector selection, and the integration of control signals via Arduino and Pixhawk interfaces.

7.1 System Design and Layout​

Image 1: Power Layout​

image

Image 2: Signal Layout​

image

The electrical power layout is divided into two sections. One line dedicated to providing HV power to the ESCs via contactor control on the Power PCB. Additionally, it provides power to the PCB for all of the propulsion system and internal components. The second line is providing HV to the UBEC to give steady and reliable power to the flight controller, telemetry air unit, and additional peripherals. The second line has a physical switch on the positive line before the UBEC to give the user control over power going to the flight controller.

The signal layout can be thought of mainly two sections, the ESCs to the flight controller and the PCB to the flight controller. These two sections will operate on separate CAN lines. The ESCs will connect to the flight controller's CAN 1 and use the DroneCAN protocol. The battery (currently unused) and the radar altimeter will connect to the CAN2 port. The only additional signal being used will be two aux GPIO signals coming from the pixhawk to the PCB for relay and contactor control

7.2 Hardware Selection​

Battery

Tattu 3.5 14S - 53.2V 30000 mAh

image

  • Capable of CAN communication. Current battery used is on firmware xx.xx and was not compatible with Ardupilot.
  • Battery side connector: Molex EXTreme 46562-9206 manually latching with 46562-9306 = 46562-2657 (a non-official part number)
  • Mates to: Molex EXTreme 46437-9206 manually latching with 46437-9306
  • See Propulsion System for detailed specs

Battery Adapter

image

Power PCB

Summary of capabilities:

  • Pre-charge and Contactor control via Arduino MKR WIFI 1010
  • 12V power regulation, fused output
  • 5V power regulation fused output
  • 300A fused output
  • PWM, 5V, GND easy access with header pins
  • Communication protocols: CAN, UART, RS485, and Aux signals (PWM, GPIO, etc.)
  • 24, 14, & 8 position automotive connector for easy access to pins
  • XT90 input and output connectors

12V Regulator​

MEAN WELL RSDW40G-12

image

  • 40W Rating
  • Provides power for on board components and brush bullet dispenser motor
  • fused output

5V Regulator​

TRACO Power TMU 3-1211

  • 3W Rating
  • Provides power for brush bullet relay and 5V on PWM rails
  • fused output

Pre-charge and contactor control​

The contactor (pg.11) on the PCB controls the HV output going to the ESCs. It is controlled by the user via a toggle switch on their RC that instructs the flight controller to send a signal to the on board Arduino. This allows the user to safely disconnect the power to the ESCs and motor in the case of an emergency or at the end of operation. On the PCB, the contactor works in hand with a pre-charge circuit for safe operation. The pre-charge allows the capacitor on the ESCs to be partially filled and prevents a large in rush current once the contactor is closed. This is important to mitigate any electrical arcing and damaging the ESCs. Below is a brief explanation of how the pre-charge and contactor control is handled.

image

  • Arduino sends signal to pre-charge relay (K1) when it receives command from flight controller for "contactor close"
    • this allows for a low current to pass through multiple pre-charge resistors (R1-R3), bypassing the contactor, to the ESCs
    • after 5 seconds, the Arduino sends signal to the contactor relay (K2), effectively closing the contactor
    • the precharge is then turned off

Arduino​

Arduino MKR WIFI 1010

  • used to send a timed enable signal for the pre-charge circuit
  • after a short period, enable signal sent to close contactor
Sketch​

Quiver PT1 sketch.zip

      #include "thingProperties.h"
      #include "WiFiNINA.h"
      #include "utility/wifi_drv.h"
      
      int contactor_pin = 2;
      int precharge_pin = 1;
      int led_green_pin = 26; // Green LED
      int led_red_pin = 25;   // Red LED
      int led_blue_pin = 27;  // Blue LED
      
      int control_input_pin = 16; // Placeholder digital input pin for contactor control
      
      unsigned long lastCloudUpdate = 0;
      const unsigned long cloudUpdateInterval = 2000; // Call ArduinoCloud.update() every 2 seconds
      
      // Debounce variables
      bool lastInputState = false;
      bool lastStableState = false;
      unsigned long debounceTime = 0;
      const unsigned long requiredStableTime = 1000; // 1 second required for stable input
      
      void setup() {
        Serial.begin(9600);
        delay(1500);
        Serial.println("Starting setup...");
      
        initProperties();
      
        // Set initial LED state: green on, red off
        WiFiDrv::pinMode(led_green_pin, OUTPUT);
        WiFiDrv::pinMode(led_red_pin, OUTPUT);
        WiFiDrv::pinMode(led_blue_pin, OUTPUT);
        WiFiDrv::analogWrite(led_green_pin, 255); // Turn on green LED
        WiFiDrv::analogWrite(led_red_pin, 0);    // Turn off red LED
      
        pinMode(contactor_pin, OUTPUT);
        digitalWrite(contactor_pin, LOW);
      
        pinMode(precharge_pin, OUTPUT);
        digitalWrite(precharge_pin, LOW);
      
        pinMode(control_input_pin, INPUT);
      
        connectToWiFiAndCloud();
      }
      
      void loop() {
        unsigned long currentMillis = millis();
      
        // Cloud update handling
        if (WiFi.status() == WL_CONNECTED) {
          if (currentMillis - lastCloudUpdate >= cloudUpdateInterval) {
            lastCloudUpdate = currentMillis;
            ArduinoCloud.update();
          }
        } else {
          Serial.println("WiFi disconnected.");
        }
      
        // Read the control input state and debounce
        bool currentInputState = digitalRead(control_input_pin);
      
        if (currentInputState != lastInputState) {
          // Input state changed, reset the debounce timer
          debounceTime = currentMillis;
          lastInputState = currentInputState;
        }
      
        // Check if the input has been stable for the required time
        if (currentMillis - debounceTime >= requiredStableTime) {
          if (currentInputState != lastStableState) {
            // Update stable state and control the contactor
            lastStableState = currentInputState;
            contactor_control = currentInputState;  // Update contactor control state
            onContactorControlChange();
          }
        }
      }
      
      void connectToWiFiAndCloud() {
        Serial.println("Connecting to WiFi...");
        WiFi.begin(SECRET_SSID, SECRET_OPTIONAL_PASS);
        unsigned long startAttemptTime = millis();
        const unsigned long wifiTimeout = 2000; // 2 seconds timeout
      
        while (WiFi.status() != WL_CONNECTED && millis() - startAttemptTime < wifiTimeout) {
          delay(500);
          Serial.print(".");
        }
      
        if (WiFi.status() == WL_CONNECTED) {
          Serial.println("\nWiFi connected!");
          ArduinoCloud.begin(ArduinoIoTPreferredConnection);
          Serial.println("Connected to Arduino IoT Cloud!");
        } else {
          Serial.println("\nFailed to connect to WiFi within the timeout period.");
        }
      }
      
      void onContactorControlChange() {
        if (contactor_control) {
          // Start precharge when contactor control is enabled
          digitalWrite(precharge_pin, HIGH); // Turn on precharge
          delay(5000); // Wait for 5 seconds to complete precharge
          digitalWrite(contactor_pin, HIGH); // Close the contactor
          delay(500); // Wait for the contactor to close
          digitalWrite(precharge_pin, LOW); // Turn off precharge
      
          // Turn LED red
          WiFiDrv::analogWrite(led_green_pin, 0); // Turn off green LED
          WiFiDrv::analogWrite(led_red_pin, 255); // Turn on red LED
        } 
        else {
          // Turn off both precharge and contactor if contactor control is disabled
          digitalWrite(precharge_pin, LOW);
          digitalWrite(contactor_pin, LOW);
      
          // Turn LED green
          WiFiDrv::analogWrite(led_green_pin, 255); // Turn on green LED
          WiFiDrv::analogWrite(led_red_pin, 0); // Turn off red LED
        }
      }
      
      void onPrechargeControlChange() {
        digitalWrite(precharge_pin, precharge_control ? HIGH : LOW);
}

Automotive Connectors​

  • 23 Pos Connector (Mouser #: 571-1-776087-1)
    • Used for CAN, GPIO signals, and GND to the Pixhawk
  • 8 Pos Connector (Mouser #: 571-1-776280-1)
    • Used for radar altimeter power and CAN needs
  • 14 Pos Connector (Mouser #: 571-1-776267-1)
    • Used for power and signal to Brush Bullet Dispenser

Detailed pinouts can be found in the TO/FROM table.

Design Files​

CAD and Fab files image

Table 3. Mouser BOM

RefPart NumberQtyPriceDescription
F1504-AMX-3001$9.31Bussmann/Eaton AMX Fuse, 300A
F2693-3403.0170.112$0.66Schurter UMT 250 2.5A Fuse
F3, F14, F16, F22576-178.6165.00027$3.61Littelfuse FLR (ATO) PCB Fuse Holder
J1, J2710-74613832$2.71Wurth Elektronik Pin-Plate Terminals
J8571-282834-41$1.92TE Connectivity 4P Terminal Block
J9200-TSW10625GTRA1$2.30Samtec PCB Header
J12571-1-776280-11$8.52TE 8 POS Automotive Connector
J14, J15200-SSW11401TS2$1.83Samtec Socket Header
J17571-1-776087-11$11.41TE 23POS Automotive Connector
J19571-1-776267-11$8.39TE 14POS Automotive Connector
K1849-CPC1718J2$7.57IXYS DC Solid State Relay
K2849-CPC1916Y2$5.87IXYS 100V Solid State Relay
LED1720-LST676-Q1R2-1-Z2$0.30ams OSRAM Red LED
PS1495-TMU3-12112$8.90TRACO Power 3W DC/DC Converter
Q1522-FMMT555TA2$0.31Diodes Inc PNP Transistor
R1-R3652-PWR163S-25-50R0F4$3.94Bourns 25W 50 Ohm Resistor
R4, R5603-RC0805FR-07220RL4$0.10YAGEO 220 Ohm Resistor
R6, R9603-RC0805FR-07100KL4$0.10YAGEO 100k Ohm Resistor
R7, R11603-RC0805FR-077K5L4$0.10YAGEO 7.5k Ohm Resistor
R8603-RC0603FR-07680RL2$0.10YAGEO 680 Ohm Resistor
S1179-SLW-913535-2ASMT2$0.53CUI Slide Switch
Arduino782-ABX000231$38.60Arduino MKR WIFI 1010
Solder910-TS391LT101$28.95Chip Quik Solder Paste
PS2709-RSDW40G-121$46.79MEAN WELL 12V DC/DC Converter
C1, C2710-8850121080124$1.30Wurth 47uF Capacitor

UBEC

image

The KDE UBEC "allows for clean, voltage-regulated power for critical flight electronics and peripheral equipment (including 12V aerial photography and high-end UAS equipment)". The UBEC was added to avoid having a secondary power supply to the flight controller and any peripheral systems. The 12V regulator on the PCB would experience too much load if it attempted to power the PCB, brush bullet, and flight controller. Using a UBEC is an easy integration and allows for a clean 12V power delivery to mission critical components.

A toggle switched was placed on the positive lead going to the UBEC from the battery to give the user manual control over the power flowing through the UBEC to the flight controller.

XT60 Splitter

image

TL60-10 Power Distribution Module XT60 Nothing too technical here. We opted for a simple splitter to handle all of the XT60 connections to the ESCs.

ESC

See Propulsion System section for detailed description on the HobbyWing X6 Plus

Flight Controller

Radar Altimeter

Us-D1 Radar Altimeter

image

The Ainstein AI Altimeter is a small form factor device that reports reliable measurements up to 50m. The US-D1 comes with a Molex (50579204) 4-pin, 2.54mm connector. This connector required a modification in order for us to use it with the 8 position automotive connector.

Verify that the following parameters are used on the Flight Controller:

  • CAN_P2_DRIVER = 1 (first can port driver set to driver 1)
  • CAN_D2_PROTOCOL = 7 (USD1 protocol for driver 1)
  • RNGFND1_TYPE = 33 (USD1_CAN)
  • RNGFND1_MIN_CM = 50
  • RNGFND1_MAX_CM = 4500
  • RNGFND1_GNDCLEAR = 10 or more accurately the distance in centimeters from the range finder to the ground when the vehicle is landed. This value depends on how you have mounted the rangefinder.

It is important to note that the altimeter should not be tested in doors to get accurate readings. Please test the altimeter outside and verify that the distance being read is correct.

GPS

  • M9N and M10 GPS from Hollybro
  • connects to GPS1 and GPS2 ports on pixhawk

Telemetry

SIYI HM30 Air Unit

image

  • Signal Output: 16 channels of S.BUS, 5 channels of PWM

Interface & Ports:

  • SBUS: 3-Pin

  • Datalink (to FC): UART 4-Pin

  • PWM Channel 1 to 5: 6-Pin

  • Video Input: Ethernet 8-Pin

  • Firmware Upgrade: Type-C

  • Dimensions (antenna excluded, fan included): 70 x 55 x 16 mm

  • Weight (antenna excluded): 74 g

  • Antenna Gain (standard omni): 5 dBi

  • Power Input: 11 to 16.8 V (expandable to 4S to 18S with BEC)

Integration doc prepared by Alexander Dada

Gimbal Camera

Siyi A8 Gimbal Camera

image

Brush Bullet Dispenser

Brush Bullet Applicator Pod

Arrow Variant Onshape Model

brush-pod_assy (1)

Relay

A relay is used to control the motor inside of the dispenser. 5V and GND provided by PCB. Use the PWM 1 output on the PCB to send the signal from the flight controller to close the relay. The motor was connected using the COM and NO pins on the relay. This left the motor in an off state by default.

image

Attachment Interface

image

  • Connection from the Power PCB to the attachment interface for the brush bullet dispenser relied on self soldering heat shrink . This was mainly done to allow a connection from a 20 AWG cable to 24 AWG cable. Some lines were doubled up to account for the higher current needs with a smaller cable. The following cable scheme was used:

    • 12V
      • 3 cables for positive -Green, Blue, and Yellow
      • 2 cables for negative
        • Orange and White
    • 5V
      • Red for Positive
      • Black for negative
    • Signal
      • Brown

7.3 Wiring Diagram​

image

Table 4: TO/FROM Connections​

FROMConnectorTOConnectorCable Length (cm)AWGTypeNotes
14S Tattu Smart BatteryTattu AdapterPower PCBXT90650VLocation (?)
14S Tattu Smart BatteryTattu AdapterPower PCBHDR 14POS R/A Pins 7&8 (J19)20CANBJ19 Pin 7 & 8
Power PCB POS Bus AM5 Ring TerminalContactor AM5 Ring Terminalcustom
Contactor BM5 Ring TerminalPower PCB POS Bus BM5 Ring Terminalcustom
Contactor AUXloose cablesPowerPCBScrew Terminal J8customwill have to extend cables. Note current layout for wiring
Power PCBHDR 14POS R/A Pins 3,4,5,6 (J19)Brush Bullet Dispenser Attachment8 pos JST40205V,GND,12V,GND3 pins for 12V and GND (2) each, power for relay and motor
Power PCBPWM Pin 1 (J9)Brush Bullet Dispenser Attachment8 pos JST4024Signalsignal for relay
Power PCBPWM Pin 2 (J9)Arduino MKRWiFi 1010 Pin A1 - 16 (J14)Header or solderSignalSignal from Pixhawk to enable precharge and contactor close
Brush Bullet Dispenser AttachmentSolder PadBrush Bullet Relay (COM)Screw terminal2012V +
Brush Bullet Relay (NO)Screw TerminalBrush Bullet MotorSolder heat shrink2012V +
Bush Bullet Dispenser AttachmentSolder PadBrush Bullet MotorSolder heat shrink2012V GND
Brush Bullet Dispenser AttachmentSolder PadBrush Bullet Relay (DC+, DC-, IN)Screw terminal205V, GND, EN
Power PCBHDR 23POS R/A Pins 8,11,12 (J17)Pixhawk CAN 22mm Molex 4-pin6020CANB L, H, GNDwill have to use a self solder heat shrink to 24 AWG cable
Power PCBHDR 23POS R/A Pins 1 & 2 (J17)Pixhawk PWM Main Pin 8 & 7Header60PWMSend enable signal to
Power PCBHDR 8POS R/A Pins 6,7,8 (J12)Radar AltimeterCustomCAN, 5VNeed to move to CAN B (?)
Power PCBXT90 FTL60-10XT90 M (Solder Cables)
TL60-10XT60ESC1Crimp or XT608350V
ESC1UnsurePixhawk CAN2mm Molex 4-pin83 + ?24CAN L, H, GNDI2C Splitter
TL60-10XT60ESC2Crimp or XT6083850V
ESC2UnsurePixhawk CAN2mm Molex 4-pin83 + ?24CAN L, H, GNDI2C Splitter
TL60-10XT60ESC3Crimp or XT6083850V
ESC3UnsurePixhawk CAN2mm Molex 4-pin83 + ?24CAN L, H, GNDI2C Splitter
TL60-10XT60ESC4Crimp or XT6083850V
ESC4UnsurePixhawk CAN2mm Molex 4-pin83 + ?24CAN L, H, GNDI2C Splitter
Tattu AdapterSpade TerminalUBEC SwitchCrimp or XT30UBEC Default1650VPositive cable to switch only
UBEC SwitchXT30UBEC
UBECXT30 MPM02DXT30 FCockpit height1612V
PM02DXT30 (M or F?)Pixhawk Power 12mm Pitch Molex 6-pin (Molex Part: 5024430670)Default245V, I2C
PM02DXT30 (M or F?)HM30 TXXT30 M1612V
HM30 TXEthernetSIYI A8 Gimbal8 Pin MolexLAN & PWR

8. Geometry & Structure

The design of this aircraft centers on accommodating frequent modifications and upgrades, preserving straightforward access to all key components. By employing a modular architecture and standardized interface points, the system can be quickly reconfigured or expanded to integrate novel sensors, payloads, or propulsion elements. Structural integrity is achieved through robust materials such as aluminum 7075 and 3D-printed carbon fiber nylon and connections that distribute loads uniformly. This approach enables the prototype to withstand potentially harsh landings, while finite element analysis (FEA) helps validate each subsystem’s load-bearing capacity. Furthermore, by minimizing mass through efficient structural layouts and selective material use, the aircraft maintains better flight performance, high agility, and reduced power consumption to extend operational times.

8.1. Overall Geometry​

The overall geometry is largely symmetrical, with key components arranged around a central thrust plane. The battery is intentionally placed slightly above this plane, shifting the center of gravity (CG) upward. During mission, lower-mounted attachments help balance the airframe, ensuring that the CG remains near the thrust plane’s center. This symmetrical configuration, combined with the modular design, makes it straightforward to reposition or replace entire subsystems while preserving stable flight characteristics.

Below is a summary of the aircraft’s key dimensional parameters:

ParameterMeasurement
Folded Width62 cm
Folded Length60 cm
Unfolded Width95 cm
Unfolded Length95 cm
Overall Height68 cm
Max Attachment Height40 cm
Max Attachment Diameter30 cm

These dimensions ensure balanced weight distribution in both folded and unfolded states while providing adequate space for payloads and accessories.

Subsystem Weight Breakdown​

Below is an approximate weight breakdown for each major subsystem, noting the primary materials involved. These figures are meant to serve as general estimates and may vary based on final manufacturing processes, hardware choices, and tolerances.

Table 5. Subsystem Weight

SubsystemMaterial(s)Approx. Weight
Main ChassisAluminum 7075 & Carbon Fiber Nylon1500 g
4x Motor & ArmCarbon Fiber Tubes & Aluminum4200 g
Landing GearCarbon Fiber & Aluminum800 g
Battery EnclosureCarbon Fiber Nylon1100 g
Electrical CompartmentCarbon Fiber Nylon200 g
AvionicsAluminum / 3D-Printed CF Nylon300 g
CameraCamera Lens & Gimbal / Equipment Holder500 g
Misc. HardwareFasteners, Harness, Electrical Components300 g
Estimated Total-8900 g

Please note that these weights are not definitive values and should be verified after prototype assembly and testing.

8.2. Detailed Zones​

Main Chassis​

Two parallel aluminum plates—each 3/32" (2.5 mm) thick and fabricated from aluminum 7075—form the central chassis of the aircraft. These plates provide the main structural backbone. They're connected by the motor mounts on the corners and a 3D-printed carbon fiber nylon cube clamped at the center. The center cube accommodates holes on the sides to leave access for the attachment harness.

Motors​

Each motor is situated at the end of a 30 cm-long, 30 mm-diameter carbon fiber arm that extends radially from the central chassis. These arms are attached to the plates using hinged, foldable connectors made of aluminum. The hinging mechanism typically includes a locking pin, which secures the arms in flight position and allows rapid folding for compact transport. The motor mounts are supplied by the motor manufacturer, embedded around the motor.

Landing Gear​

The landing gear system employs 20 mm-diameter carbon fiber tubes attached with off-the-shelf aluminum housing under the central chassis. Two vertical tubes are connected to one horizontal tube on the bottom with aluminum tube connectors. The tubes position the aircraft at a large ground clearance, giving enough height for any attachments.

Battery Enclosure​

Located near the geometric center of the aircraft, the battery enclosure ensures a balanced center of gravity for stable flight control. This enclosure is dimensioned to accommodate the selected battery module, as well as batteries in the same battery family with lower capacity.

Enclosure Structure:

  • A 3D-printed carbon fiber nylon box that attaches directly to the upper chassis plate. It also provides two sliders for the battery, ensuring that the vertical movement is prevented.
  • A 3D-printed carbon fiber nylon hatch on the enclosure, protecting the battery from exterior. A cut-out ensures visibility for the battery on-off button and battery charge indicator.
  • A 3D-printed carbon fiber nylon cap over the enclosure, featuring integrated cut-outs for ventilation and weight reduction.

Electrical Compartment​

The electrical compartment consolidates the power distribution board (PDB), battery connector, and high-voltage and signal cables between the electrical and propulsion system components. The battery connector is located on a connector stand, which has a latch to lock the battery in place. By placing the electrical compartment between the main chassis plates, the design makes the overall size of the aircraft smaller and simplifies cable routing. The PDB and battery connector are removable for any troubleshooting or replacement.

Avionic Bay​

The avionic bay houses core navigation and control components, including flight controllers, GPS antennas, and telemetry antenna. By isolating these critical electronics from power systems, the design maintains cleaner data signals and more accurate sensor readings. The avionics are placed on the top of the battery enclosure.

Underside Equipment​

The underside of the aircraft provides a dedicated zone for mounting the attachment, radar altimeter, and the gimbal camera. The attachment is connected to an interface utilizing a quick release mechanism. The interface is connected to the chassis for better structural support. The gimbal camera is located on a 3D-printed holder to increase the view angle. The radar altimeter is placed so that the operational field of view is not affected by the attachment and the landing gear.

8.3 FEA analysis​

Will demonstrate how the structure will behave under the following forces

  • 12 Kg of force acting at each motor (full throttle)

  • 12 kg of force acting on the cockpit (weight from all equipment)

  • The materials in the study are:

    • Aluminum 6061 for all the foldable motor arm connector, landing gear joints, and motor beam ends.
    • Aluminum 7075 for cockpit plates
    • Carbon fiber for the motor arms and land legs.

NOTE Structure is constrained at a “imaginary” plate added in the middle to simulate a solid structure with free movement.

Displacement​

image

Stress​

image

Results Summary​

  • The results yielded a 1.53 safety factor, meaning that the design at full throttle is marginal and could fail if external forces (bad weather, unexpected maneuvers) are acting.

  • The max displacement of one of the motor beams reached 10.77 mm

  • The max stress occurred at the motor beam to foldable motor arm connector with a value of 17 Mpa.

Recommendation: Since these were the results at full throttle, it is unlikely we will be in this condition. The recommendation is to perform a bench test on the motor arm in order to see how it behaves under various throttle outputs.

9. Appendix