How to Assemble an FPV Drone
Composition and Classification of FPV Drones
To get a quadcopter off the ground, at minimum you need: a frame, four motors (with propellers), a flight controller (FC), an electronic speed controller (ESC, typically 4-in-1), a receiver, and a transmitter. With these components, your drone can take off and land under remote control.
For FPV drones, an additional video transmission system (VTX system) is required.
If you're unfamiliar with these terms, don’t worry—we’ll explain each component in simple language below.
Frame – Skeletal System
If we compare a drone to a human, the frame is like the torso. It connects and supports all other systems.
Most drone frames are made of carbon fiber, which determines the drone’s size and power layout.
Motors + Propellers – Movement System
Motors are like human limbs. They rotate the propellers to generate thrust.
The motor model determines power output, and the motor’s KV rating must match the battery voltage.
Flight Controller (FC) – Nervous System
The FC is like the brain. It processes incoming data and can carry sensors like a gyroscope to sense flight attitude in real time.
Common FC models include the F405 series and F722 series, where the number refers to the MCU chip (e.g., STM F405, STM F722).
Different MCUs offer varying processing power. Higher performance FCs allow for more advanced features—but also come at a higher cost.
Electronic Speed Controller (ESC) – Muscular System
The ESC is like the muscles. It controls motor rotation.
You may see ESCs labeled like: BLHeli_S 32-bit 50A, BLHeli_S 8-bit 60A, or Bluejay 8-bit 60A.
“BLHeli_S” and “Bluejay” refer to the firmware.
“32-bit” and “8-bit” refer to the processing power—more bits mean faster calculations and smoother flight.
“50A” or “60A” indicates the maximum sustained current per ESC channel.
Receiver and Transmitter – Auditory System
Choosing a Transmitter and Receiver
The receiver is like the ear. It receives signals from the transmitter and passes them to the FC (brain).
Common receiver protocols include ELRS, TBS (Crossfire), and DJI. The receiver must match the transmitter protocol.
A receiver system includes both the transmitter and receiver. The transmitter sends commands, the receiver receives them, and the FC processes them to control the drone.
Popular receivers include TBS Crossfire and ELRS.
- Crossfire receivers require a Crossfire transmitter module.
- ELRS receivers need an ELRS transmitter or module.
- If you use DJI's Air Unit, it has a built-in receiver, so you don’t need a separate one. Note: This only works with a DJI-compatible remote controller.
Video Transmission (VTX) System
A complete VTX system includes: camera, transmitter (VTX), and receiver (VRX).
There are two types: digital VTX and analog VTX.
As the names suggest, digital transmits digital signals, and analog transmits analog signals.
Differences:
- Digital VTX: higher image quality, better anti-interference.
- Analog VTX: lower image clarity, less anti-interference—but more affordable and flexible. Digital VTX systems require brand-specific compatibility (transmitter and receiver must be from the same brand), making them more expensive. Analog systems only need the transmitter and receiver to share the same frequency band, making them budget-friendly. The most popular digital VTX is DJI Air Unit. Analog options vary, but work similarly. For example, SpeedyBee TX800 is an 800mW analog VTX—higher power means longer transmission range. For analog video receivers, choose one that supports 5.8GHz.
Common FPV Drone Terminology
• FPV (First-Person View): Viewing the flight live from the drone’s perspective, without gimbal stabilization.
• RTF (Ready-To-Fly): Pre-assembled and includes everything you need to start flying immediately.
• BNF (Bind-And-Fly): Requires binding to your own transmitter; goggles, battery, and other gear commodity separately.
• PNP (Plug-And-Play): Needs separate purchase of receiver, goggles, transmitter, and battery.
• Power Kit: Includes motors, ESC, and sometimes the frame; requires additional receiver, goggles, battery, and video system.
• AIO (All-In-One): FC and ESC combined on one board.
• Firmware: A compiled file written to the FC’s MCU that defines how pins and functions are assigned.
• Configurator: Software used to flash firmware to the FC. Examples include Betaflight Configurator, INAV Configurator.
• Crash: A flight failure where the drone crashes due to operator error or hardware fault.
• Binding: The process of pairing a transmitter with a receiver to establish communication.
• Illegal Flying (Black Flight): Flying without a license or without legally registered aircraft. Always fly legally and follow local UAV regulations.
• Mode 1/2 (American Hand, Japanese Hand, etc.): Refers to the throttle and direction stick configuration on the transmitter.
• Angle Mode: Stabilized mode where the FC automatically levels the drone.
• Acro Mode: Manual mode with no auto-leveling. The drone will keep rotating unless corrected by the pilot—used in freestyle and racing.
• Horizon Mode: A hybrid mode; near-center sticks act like Angle mode, but further movement behaves like Acro.