MGL Avionics Autopilot servo choices

MGL Avionics servo (MGL servo details) Trio Avionics Gold standard servo (
Stepper motor based, single stage spur gear DC motor based, mutiple stage spur gear
No clutch, minor residual torque if not engaged Electric clutch, no residual torque if not engaged
CAN and RS232 interface Psuedo RS232 interface
Can be used with Odyssey, Voyager, Enigma, XTreme Can be used with Odyssey, Voyager, Enigma
May need COM Extender module for Enigma if serial port used for other purpose Needs COM Extender module in all cases
Output shaft can operate over any range and angles

Output shaft operates over fixed range and anges
 (arm can be positioned in 90 degree steps)

Safety override: Shear screw Safety override: Internal, sacrificial gear
Electronically adjustable output torque Output torque adjustable mechanically (requires opening of servo)
Direct motor overdrive Slipper clutch on output shaft
Two moving parts (motor shaft, output shaft) Many moving parts
Contactless position sensing Position sensing using potentiometer
Capable of measuring actual force acting on output shaft (trim sensing) No internal trim sensing
Heavier than Trio servo (1.38Kg) Lighter than MGL servo (0.8Kg)
Electrical interface connection: D9 connector Electrical interface connection: Flyleads to automotive connector
Higher cost compared to the Trio servo Lower cost than the MGL Servo
Operates from 12V and 24V (28V) systems 12V systems, requires pre-regulator for 24V systems
Current requirement approximately 1A average (engaged), 0.6A at 24V Current requirement approximately 1A average (engaged)

The above table gives a basic comparision for servo choices applicable to the MGL EFIS systems. Overall, the servos perform much the same function but small differences may be of advantage for either choice depending on your particular application.
The MGL servo may be of advantage for aircraft with low stability / sensitive controls due to increased speed and greater position accuracy. The Trio servo performs well in stable aircraft where absolute accuracy and speed are of less importance.




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