diff --git a/actuators.md b/actuators.md
index fd8066c6f..59011f992 100644
--- a/actuators.md
+++ b/actuators.md
@@ -4,7 +4,7 @@ title: Actuators
 ---
 
 
-## joint servo motor
+## joint and gimbal servo motor
 ### dynamixel
 you can use [dynamixel_wizard2](http://emanual.robotis.com/docs/en/software/dynamixel/dynamixel_wizard2/) to set the configuration from ubuntu/windows.
 
@@ -20,6 +20,15 @@ you can use [dynamixel_wizard2](http://emanual.robotis.com/docs/en/software/dyna
 - `return delay time: 25[ms]`
 - `operating mode: 5`
 
+#### id setting
+Slave_id of each neuron is incremented from 1 and set rqt.  
+ID of servo motors connected to the same neuron is incremented from 1 for joints and gimbals, in that order.  
+The valie of each ID in the Servo.yaml is incremented from 0 starting from the servo with ID 1 connected to neuron with slave_id 1.  
+
+|slave_id of neuron|1|1|2|2|2|3|  
+|id of dynamixel|1|2|1|2|3|1|  
+|id in Servo.yaml|0|1|2|3|4|5|  
+
 ## thrust rotor 
 - motor specification measurement: See [here](https://github.com/tongtybj/aerial_robot/blob/master/aerial_robot_nerve/motor_test/README.md)