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HappyModel Crux35 - ELRS X1 CrazyF411 BLHELIS 5A OVX303 300mW Caddx Ant 1200TVL EX1404 KV3500 4S 3.5inch FPV Freestyle Drone

HappyModel Crux35 - ELRS X1 CrazyF411 BLHELIS 5A OVX303 300mW Caddx Ant 1200TVL EX1404 KV3500 4S 3.5inch FPV Freestyle Drone


Regular price $163.62 USD
Regular price $229.06 USD Sale price $163.62 USD
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48 orders in last 90 days


Warehouse: China/USA/Europe, can delivery to all countries;

Free Shipping: 9-15 days;

Express Shipping: 5-8 days;

Return&Refund: 30 Days.

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Use: Vehicles & Remote Control Toys

Upgrade Parts/Accessories: other

Tool Supplies: other

Remote Control Peripherals/Devices: Remote Controller

Recommend Age: 12+y

RC Parts & Accs: Receivers

Origin: Mainland China

Model Number: Crux35

Material: Composite Material

Four-wheel Drive Attributes: other

For Vehicle Type: Helicopters

Brand Name: Foxeer

Brand Name: happymodel

CRUX35/CRUX35 HD is an ultra-lightweight 3.5Inch FPV Freestyle FPV Racing Drone, the weight of the whole drone is only 87g for the analog version and 108g for the digital HD version. The Crux35 serials drone use Happymodel EX1404 high-efficiency motor and HQPROP 3.5-inch three-blade propeller to ensure the largest thrust-to-weight ratio under the most efficient premise, which can bring you a smooth Freestyle flying experience.

The HD version is equipped with CADDXFPV Nebula and Vista HD image transmission system. The analog version is equipped with CADDXFPV Ant ant camera.

The receiver version can be SPI ExpressLRS and SPI Frsky (S-FHSS compatible) for choose.

ExpressLRS is the most popular RC link system by now , it could performance very well with Crux35 and Crux35 HD. 


Ultra-lightweight 3.5-inch BNF FPV Freestyle Drone

HD video transmission and analog video transmission are optional

Integrated ExpressLRS SPI receiver or Frsky SPI D8/D16 receiver

High efficiency EX1404 power system

Can be equipped with Naked Gopro or SMO4K

Support 3-4S battery 4S 750mah battery is recommended, maximum support 4S 1100mah


Brand: Happymodel

Product name: Crux35 / Crux35 HD

Wheelbase: 150mm

Weight: Crux35 87gram

             Crux35 HD 108gram

Size: 130mmx130mmx45mm(without propellers)

Receiver option: SPI ExpressLRS 2.4GHz

               SPI Frsky D8/D16 (S-FHSS compatible)

Camera option: HD version Nebula+Vista

              Analog version Ant+OVX303 VTX

Flying time: 9min~15min 4s 750mah battery

Package includes:

Item Name


Crux35 HD

Crux35 Frame



Option1: ELRS X1 flight controller



Option2: CrazyF411 flight controller

CaddxFPV Digital HD Camera Nebula Nano Kit



Analog FPV Camera Caddx Ant



Happymodel OVX303 5.8G analog VTX



Happymodel EX1404 KV3500 brushless motor



HQProp T3.5X2X3Grey (4cw+4ccw)



Screw Driver



Buckle Velcro for battery




Mode: EX1404
KV options: KV3500
Stator Diamter:14mm
Stator Length:4mm
Shaft Diameter: Φ1.5mm
Motor Dimension(Dia.*Len):Φ15mm*15mm


Propeller Diameter: 3.5 inch
Pitch : 2
Blades : 3
Material : Poly Carbonate
Weight : 1.5g
Hub Diameter : 10mm
Hub Thickness:4.7mm
Shaft :1.9/1.5/1.9mm
Adaptor Rings : NO

Flight controller

(ELRS Version)

MCU:STM32F411CEU6 (100MHZ, 512K FLASH)
Sensor: MPU-6000(SPI connection)
Mount pattern: 20x20 M2


Power supply: 2-4S Lipo battery

Built-in 12A Blheli_s ESC each

Built-in Betaflight OSD(SPI Control)
Built-in SPI ExpressLRS 2.4GHz receiver

Built-in 5V 1A BEC

Flight controller firmware target: CRAZYBEEF4SX1280

Flight controller

(Frsky version)

MCU:STM32F411CEU6 (100MHZ, 512K FLASH)
Sensor: MPU-6000(SPI connection)
Board size: 28.5 * 28.5MM
Power supply: 2-4S battery input (DC 8V-17V)
Built-in 20A(each) Blheli_S 4in1 ESC Dshot600 ready
Built-in Frsky D8/D16 SPI receiver

Built-in 2.4G Power Amplification
Built-in Betaflight OSD(SPI Control)
Built-in Current meter
Built-in 5V 1.5A BEC
Built-in voltage detection

Firmware target: MATEKF411RX

Onboard 4in1 ESC

MCU upgraded to EFM8BB21
Power supply: 1S LiPo/LiPo HV

Current: 5A continuous peak 6A (3 seconds)
Support BLHeliSuite programmable
Factory firmware: O_H_5_REV16_8.HEX
Default protocol: DSHOT300

Onboard SPI ExpressLRS 2.4GHz Receiver

(ELRS version)

Packet Rate option: 25Hz/50Hz/150Hz/250Hz/500Hz
RF Frequency: 2.4GHz

Antenna : SMD antenna
Telemetry output Power: <12dBm

Receiver protocol to flight controller: CRSF

Could bind with Happymodel ES24TX , ES24TX Lite, ES24TX Slim and DIY 2.4GHz ELRS TX module

Onboard SPI Frsky 2.4GHz receiver (Frsky Version)

SPI BUS receiver
Frsky D8/D16/EU-LBT/, Futaba S-FHSS switchable on Betaflight 
Channels: 8ch/16ch

Dual antenna
Failsafe support
No ground interference ( Transmitter and receiver 1 m from the ground): 400m

CaddxFPV Digital HD Camera Nebula Nano Kit

(Digital HD version)

Weight(camera included]: 24g

Antenna: 2.3g

Dimensions: Vista Kit 30×29×13mm

                    Camera 14×14×21mm

Operating Frequency: 5.725-5.850GHz

Transmitter Power[EIRP]: FCC/SRRC/MIC:<30dBm


Min.latencylend-to-end) 720p 60fps:32ms

Max.Transmission Distance FcC/SRRC: 4km


lnput Power: 7.4-26.4V

Power Output: 25mW/200mW/500mW/700mw

Goggles : Work with DJl goggles


Sensor: 1/3”CMOS




LHCP antenna

Caddx ANT 1200tvl camera

(Analog version)

Image Sensor: 1/3" CMOS Sensor

Horizontal Resolution: 1200 TVL

TV System: NTSC or PAL

IMAGE: 16:9 or 4:3

Synchronization: Internal

Electronic Shutter: PAL: 1/50~100,000; NTSC: 1/60~100,000

S/N Ratio : >52dB (AGC OFF)

Video Output: CVBS

Lens: 1.8mm

Min. Illumination: 0.001Lux@F1.2

Auto Gain Control: YES


WDR: Global WDR


Dimensions: 14*14mm(with bracket to 19*19mm)

Wide Power Input: DC 3.7-18V

Work Temperature: -20℃~+60℃

Weight: 2g (N.W.)

OVX303 5.8Ghz VTX

(Analog version)

Model: OVX303

Frequency: 5.8G 40CH

Transmitting Power: 0/RCE/25mw/100mw/300mw

Power supply: DC 5V

Current (5v): <650ma (300mw)

Weight: 1.5gram without antenna

HappyModel Crux35, the analog version is equipped with CADDXFPV Ant ant camera





Related Article:

HappyModel Crux35 Review

 **Review: HappyModel Crux35 - ELRS X1 CrazyF411 BLHELIS 5A OVX303 300mW Caddx Ant 1200TVL EX1404 KV3500 4S 3.5-inch FPV Freestyle Drone**

The HappyModel Crux35 is an ultra-lightweight 3.5-inch FPV freestyle drone that offers an impressive combination of performance and versatility. With its compact size and powerful components, the Crux35 is designed to deliver an exhilarating freestyle flying experience while providing options for both HD video transmission and analog video transmission. This review article will introduce the composition, parameters, advantages, how to choose, operation guide, frequently asked questions, and more about the HappyModel Crux35 FPV freestyle drone.

Composition and Parameters:
The HappyModel Crux35 is built using high-quality components that contribute to its overall performance. The drone has a wheelbase of 150mm and measures 130mm x 130mm x 45mm (without propellers). The weight of the Crux35 is 87 grams, while the HD version, Crux35 HD, weighs 108 grams. The Crux35 offers two receiver options: SPI ExpressLRS 2.4GHz and SPI Frsky D8/D16 (S-FHSS compatible). This allows pilots to choose their preferred receiver system for optimal compatibility. For the camera option, the HD version comes with the Nebula+Vista camera, providing high-definition video transmission, while the analog version features the Ant+OVX303 VTX for analog video transmission. The power system of the Crux35 utilizes the efficient EX1404 motor with a KV rating of 3500. The drone supports 3-4S batteries, with a recommended 4S 750mAh battery and a maximum supported battery capacity of 4S 1100mAh.

1. Ultra-lightweight Design: The Crux35's lightweight design enhances its agility and maneuverability, allowing for dynamic freestyle flying and acrobatic maneuvers. Its compact size also makes it suitable for indoor and outdoor flying.

2. Video Transmission Options: The Crux35 offers the flexibility to choose between HD video transmission (with the Nebula+Vista camera) and analog video transmission (with the Ant+OVX303 VTX). This allows pilots to cater to their personal preferences and the requirements of different flight scenarios.

3. Receiver Compatibility: With the option for either the SPI ExpressLRS 2.4GHz receiver or the SPI Frsky D8/D16 receiver (S-FHSS compatible), the Crux35 can be easily integrated with various transmitter systems, providing pilots with a wide range of options.

4. High-Quality Camera Support: The Crux35 is capable of accommodating either the Naked GoPro or the SMO4K camera, allowing pilots to capture high-quality footage for freestyle flying or cinematic shots.

5. Battery Compatibility: The Crux35 supports 3-4S batteries, with a recommended 4S 750mAh battery. This provides pilots with flexibility in choosing the battery capacity based on their desired flight time and performance.

How to Choose:
When choosing the HappyModel Crux35, consider the following factors:

1. Receiver Preference: Decide whether you prefer the SPI ExpressLRS 2.4GHz receiver or the SPI Frsky D8/D16 receiver (S-FHSS compatible) based on your existing transmitter system and personal preference.

2. Video Transmission Type: Determine whether you prefer HD video transmission (with the Nebula+Vista camera) or analog video transmission (with the Ant+OVX303 VTX) based on your preference for video quality and compatibility with your FPV

goggles or monitor.

3. Camera Requirements: If you plan to capture high-quality footage, consider whether you want to use a Naked GoPro or the SMO4K camera and ensure compatibility with the Crux35 frame.

4. Battery Capacity: Consider your flight time requirements and choose an appropriate battery capacity within the supported range of 3-4S, with a recommended 4S 750mAh battery.

Operation Guide:
1. Assembly: Follow the provided instructions to assemble the Crux35 or Crux35 HD. Ensure all components are securely attached and properly connected.

2. Receiver Setup: Depending on the receiver version you have chosen, follow the instructions provided by HappyModel to bind and configure your receiver with your transmitter.

3. Camera Installation: If using the Naked GoPro or SMO4K camera, securely mount it onto the drone using compatible mounts or accessories.

4. Powering On: Connect a fully charged battery to the drone. Ensure all components are functioning correctly, including the motors, camera, and video transmission system.

5. Flight Control Configuration: Use the Betaflight Configurator software to configure flight control settings, adjust PID values, and customize other parameters to suit your flying style. Consult the HappyModel documentation for specific configuration details.

FAQs (Frequently Asked Questions):
1. Can I use a different camera with the Crux35?
While the Crux35 comes with the Nebula+Vista camera for HD video transmission or the Ant+OVX303 VTX for analog video transmission, it is possible to use other cameras if they are compatible with the frame and provide the necessary connections. However, modifications or additional adapters may be required.

2. Can I use larger batteries with the Crux35?
The Crux35 is designed to support 3-4S batteries, with a recommended capacity of 4S 750mAh. While larger batteries may physically fit, it is essential to ensure that the drone's power system and components can handle the increased voltage and current requirements. Exceeding the recommended specifications could lead to decreased performance or damage to the drone.

The HappyModel Crux35 FPV freestyle drone offers an exciting and versatile flying experience with its ultra-lightweight design, multiple receiver options, video transmission choices, and support for different camera systems. With its powerful EX1404 power system and compatibility with various battery capacities, the Crux35 allows pilots to enjoy extended flight times while performing thrilling freestyle maneuvers. Whether you prioritize HD video transmission or prefer analog video, the Crux35 offers the flexibility to cater to your preferences. The Crux35 is an excellent choice for FPV enthusiasts who seek an agile and high-performing freestyle drone for both indoor and outdoor flying.