How to set power-up servo value? My servo goes to one very end and break the rudder on power up

I have SERVOn_MIN SERVOn_MAX set to 1100 and 1900, it works fine when ardupilot is running.

The problem is the power-up moment. When I plug-in the battery, the servo immediatly turns to one very end, probably the position of 800 PWM value, and it breaks my rudder. At the moment, OSD shows “initializing ardupilot”. After initialization finished, the servo goes to the correct position again.

Looks like the controller is not giving a right PWM value on initialization, what parameter controls the power-up servo value?

The easiest solutions is probably to change the linkage so that the position the servo starts in correspond to a reasonable position of the rudder. It is usually hard to control servo positions during boot.

I think I will adujst the mechanical connection between the servo and the rudder, so that I only use servos at their max angle, with controller value range from 800 to 2200. In this way, a 800 value will not break the rudder.

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