STACK FPV drone

A "stack" in an FPV (First Person View) drone refers to a compact, multi-layered assembly of essential electronic components, typically mounted one above the other within the drone's frame. This vertical integration is crucial for saving space and simplifying wiring in the often cramped confines of FPV drones.

A typical FPV drone stack usually comprises at least two, and often three, main circuit boards:

  1. Flight Controller (FC): This is the brain of the drone.

    • It receives commands from the pilot via the radio receiver (RX).

    • It gathers data from onboard sensors like gyroscopes and accelerometers to understand the drone's orientation and movement.

    • It then processes all this information and sends precise instructions to the Electronic Speed Controllers (ESCs) to adjust motor speeds, thereby controlling the drone's flight, stability, and maneuvers.

    • Many modern FCs also integrate features like On-Screen Display (OSD) for real-time flight data in the FPV feed, and often act as a power distribution board for other components.

  2. Electronic Speed Controller (ESC) - typically a 4-in-1: This board is responsible for controlling the speed and direction of the drone's motors.

    • A "4-in-1" ESC integrates the individual speed controllers for all four motors onto a single board, which is then designed to stack directly with the FC.

    • It converts the low-level signals from the Flight Controller into the high-power electrical pulses required to spin the brushless motors.

    • Integrating it into a stack significantly reduces the amount of wiring needed between the FC and the ESCs.

  3. (Often included) Video Transmitter (VTX): This component is responsible for sending the live video feed from the drone's camera to the pilot's FPV goggles or monitor.

    In many modern stack designs, the VTX is also built to sit directly above or below the FC/ESC layers, further streamlining the build and wiring.

Why are "stacks" used in FPV drones?

Space Efficiency: FPV drones are often built for performance and agility, requiring a small and lightweight design.Stacking components vertically makes incredibly efficient use of the limited internal space.

Clean Wiring: By having direct connections or very short traces between the stacked boards, the overall wiring complexity is drastically reduced. This leads to a tidier build, minimizes potential points of failure, and simplifies troubleshooting.

Integrated Performance: Manufacturers design these stacked components to work seamlessly together, ensuring optimal communication and power delivery between them.

Vibration Isolation: The entire stack is commonly mounted on rubber grommets or other vibration-damping materials. This is crucial for protecting the sensitive gyroscopes on the Flight Controller from motor vibrations, which can otherwise degrade flight performance and stability.

In essence, an FPV drone "stack" is a highly integrated and efficient solution for housing the core electronics that power and control the drone, enabling high performance in a compact form factor.