- Limited support for different types of helicopters. For example, PX4 does not support helicopters with coaxial or dual rotor types, and features such as RPM governor and autorotation.
# Helicopter Types
PX4 supports helicopters with a single main rotor with a swash-plate controlled by up to 4 swash-plate servos, and:
- a mechanically uncoupled tail rotor driven by an ESC, or
- a mechanically coupled tail controlled by a servo on the tail motor.
The allowed flight operations and flight modes are the same as for multicopter. Note however that (at the time of writing) 3D flying with negative thrust is not supported in autonomous/guided modes.
Assembly of the core autopilot components are similar for all frames. This is covered in Basic Assembly.
Helicopter-specific assembly consists mostly of connecting and powering the motors and swash plate servos.
Note that the flight controller cannot power motors and servos (only GPS module, RC receiver, and low power telemetry modules can be powered from Pixhawk flight controllers). Generally a power distribution board (PDB) is used to power motors, and a separate (or integrated) battery elimination circuit (BEC) is used to power each of the servos.
Helicopter configuration and setup is covered in:
- Helicopter configuration: Vehicle frame selection, actuator configuration and testing, and tuning.
- Standard Configuration: The common configuration and calibration steps for most frames. This includes configuration/calibration of core components such as compass and gyroscope, setting flight mode mappings on a remote control, and safety settings.
# Frame Builds