Pitch hunting on RV-7

[JohnH]

I installed an AP74 and 2 servos in an RV7 and with a bit of tweaking and fiddling eventually managed to get the tracking and NAV functions to an acceptable level of smoothness.

The problem with the pitch is that I cannot get it better than about a 20ft either way up and down occilation in pitch. At the annual inspection now, I find that there is play between the servo arm and the shaft driving the arm. Can anyone tell me if this is correct and how to cure it if possible.

 

[dynonsupport]

Hi John,

There should be very little play between the output arm and the servo shaft. With the AP engaged in SERVO TEST mode, the elevators should move no more than about 1 degree up or down without slipping the servo.

If you have loose arms, we have a field service procedure:

http://www.dynonavionics.com/downloads/Install_Guides/Servo%20Shear%20Screw%20Replacement%20Instructions.pdf

Or we can fix it here at the factory.

 

[JohnH]

Thanks, I found the service procedure on the web site. I have also tried to connect the servo arm to one of the inner holes on the servo arm. This will reduce the sensitivity, but this does not seem to be an option because the push-rod comes up against the servo when the elevator is full up. I will fly it again with the play fixed and see what happens.

 

[PhantomPholly]

Check your PMs.