Dynon Autopilot Servo

[P Johnson]

Does anyone know what size Dynon autopilot servo's work on the 7SS? I have measured the travel that will be required for the pitch servo and it will need the long arm variant the roll servo will have the standard arm, I would like to go with the smallest that works as they are heavy. This is one of the areas the Garmin wins over the Dynon with having one servo for all forces up to 60lbs, they are also brushless and lighter too.

[LetMeFly]

I read in other posts that the SV-32 would slip sometimes on the pitch servo so I went with the 42 for both. I didn't do enough measuring so I might have to get a long arm for the pitch as well.

[P Johnson]

LetMeFly,

After I had made my original post I found the thread on the SV32 slipping in the pitch axis, I think the SV42 should be about right as its max torque is 55lbs compared to 60lbs on the Garmin which is successfully being used, the hole positions on the long and short arms of the Dynon and Garmin servos are the same. I have done my initial setup on the elevator which may need some tweaking but the travel on the elevator push rod is 2 7/8" which is about middle hole on the long servo arm.

[68niou1]

Have you flown yours yet? I ended up getting the longer arm on my SV32, and it’s making a really bad ratcheting noise which I’m being told by Dynon that is normal because the servo is a stepping motor they say. Any truth to this?
Thanks, Scott

[P Johnson]

Scott,

I have not flown mine yet but I do have experience of the Dynon auto pilot servo's, when installed they make a whirring sound when you move them through their range, when electrically powered and they have been moved to their extremities and cannot move anymore they make a ratcheting sound this also happens when the torque is set too low or the motor is undersized.

Regards

Paul.