The Crux35 ELRS V2 URAT is an ultra‑lightweight 3.5‑inch FPV freestyle quadcopter built for maximum efficiency and smooth flight performance. Now upgraded with the CrazyF411 ELRS AIO flight controller featuring a built‑in UART ExpressLRS 2.4GHz receiver, this version replaces the discontinued SPI ELRS model. Weighing only 87g (analog), the Crux35 uses EX1404 high‑efficiency motors and HQProp 3.5″ tri‑blade props to deliver excellent thrust‑to‑weight performance for freestyle flying. Available in Analog, HDZero, and DJI HD variants, with support for Naked GoPro/SMO4K and 3–4S LiPo batteries.

Specifications

General

• High‑Concerned Chemical: None
• Origin: Mainland China
• Material: Plastic
• Recommended Age: 14+
• Package Includes: Original Box
• Aerial Photography: No
• Indoor/Outdoor Use: Indoor–Outdoor

Crux35 ELRS V2 URAT Technical Specifications

Drone

• Model: Crux35
• Wheelbase: 150mm
• Weight (Analog): 87g
• Size: 130 × 130 × 45 mm (without props)
• Battery Support: 3–4S LiPo
• Recommended Battery: 4S 750mAh (max 4S 1100mAh)
• Flight Time: 9–15 minutes (4S 750mAh)

Receiver Options

• UART ExpressLRS 2.4GHz (ELRS V2)
• SPI FrSky D8/D16 (S‑FHSS compatible)
• SPI ELRS version discontinued

Camera & VTX Options

Analog Version:

• Camera: Caddx Ant 1200TVL
• VTX: OVX303 or OVX306 (5.8GHz, 0/25/100/300mW)

HDZero Version:

• HDZero Whoop VTX + Runcam HDZero Camera

DJI HD Version:

• CaddxFPV Nebula Nano or Runcam Link Wasp Nano

Power System

Motors (EX1404 KV3500)

• Configuration: 9N12P
• Stator: 14×4mm
• Shaft Diameter: 1.5mm
• Motor Size: 15×15mm
• Weight: 9g

Propellers (HQProp T3.5×2×3)

• Diameter: 3.5 inch
• Pitch: 2
• Blades: 3
• Material: Polycarbonate
• Weight: 1.5g
• Hub Diameter: 10mm
• Hub Thickness: 4.7mm

Flight Controller Options

CrazyF411 ELRS (UART ELRS Version)

• MCU: STM32F411CEU6
• Gyro: ICM42688P or BMI270
• Mounting: 25.5×25.5 M2
• ESC: 20A BLHeli_S (built‑in)
• Receiver: UART ExpressLRS 2.4GHz
• BEC: 5V 1.5A
• Firmware Target: CRAZYBEEF4DX
• Battery: 2–4S

ELRS X1 (SPI ELRS – Discontinued)

• MCU: STM32F411CEU6
• Gyro: MPU6000
• ESC: 12A BLHeli_S
• Receiver: SPI ExpressLRS
• BEC: 5V 1A
• Firmware Target: CRAZYBEEF4SX1280

CrazybeeF411 FrSky (SPI FrSky Version)

• MCU: STM32F411CEU6
• Gyro: BMI270 or ICM42688P
• ESC: 20A BLHeli_S 4‑in‑1
• Receiver: SPI FrSky D8/D16 / S‑FHSS
• BEC: 5V 1.5A
• Firmware Target: MATEKF411RX

Onboard 4‑in‑1 ESC

• MCU: EFM8BB21
• Input: 2–4S LiPo
• Current: 12A continuous / 15A peak (3s)
• Firmware: F‑H‑40
• Protocol: DSHOT300

Receiver Details

UART ExpressLRS 2.4GHz

• Packet Rates: 25–500Hz
• Frequency: 2.4GHz
• Antenna: IPEX
• Telemetry Power: <12dBm
• Protocol: CRSF
• Firmware: ExpressLRS 3.0.1

SPI FrSky Receiver

• Modes: D8/D16/EU‑LBT/S‑FHSS
• Channels: 8–16
• Range (ground‑free): ~400m

Analog Camera (Caddx Ant 1200TVL)

• Sensor: 1/3″ CMOS
• Resolution: 1200TVL
• Aspect Ratio: 4:3 / 16:9
• Min Illumination: 0.001Lux
• WDR: Global
• Voltage: 3.7–18V
• Weight: 2g

Analog VTX Options

OVX303

• Channels: 40CH
• Power: 0/25/100/300mW
• Voltage: 5V
• Current: <650mA
• Weight: 1.5g

OVX306

• Same specs as OVX303
• Weight: 1.5g