Actuators

Actuators are parts fitted into slots, exactly like the sensors. The vehicle’s slots and their accepted types are in the configuration page, and new parts can be added following the Add a part guide.

Available actuators

Actuator	Part	Slot	Fitted by default
1345 propellers, counter clockwise	prop_1345_ccw	rotor_0, rotor_1	yes
1345 propellers, clockwise	prop_1345_cw	rotor_2, rotor_3	yes

Actuators ROS API

There is none, deliberately. On a multicopter the per rotor outputs only make sense downstream of an attitude controller, so the autopilot (PX4 SITL, ArduPilot SITL or a custom controller) is the control layer and it talks to the Gazebo motor bus directly. The marine vehicles (BlueBoat, BlueROV2) expose a normalized -1..1 throttle topic per thruster, the ArduPilot output convention; the X500’s equivalent normalized layer is the autopilot itself. Rotor joint states are bridged to /joint_states so RViz animates the props.

Gazebo transport API

gz Topic	Description	Message type
/x500/command/motor_speed	Angular velocity per rotor (rad/s), indexed by the rotor number	gz.msgs.Actuators

To spin the rotors by hand, with no autopilot:

gz topic -t /x500/command/motor_speed -m gz.msgs.Actuators -p 'velocity: [700, 700, 700, 700]'

Keep the rotor instances named rotor_0 .. rotor_3: the bus indexes actuators by that trailing number.