Autopilot servo test problems

[DonFromTX]

My AP calibrate and test seems to have a problem. Although at the end of the test, it says it passed, it is acting differently than it originally did.
During the test, it moves the stick to the stop limits in each direction, and makes a buzzing sound while there. Earlier when testing, the stick did not move to its stop limits, only a ways in that direction and stopped.
Am I doing something wrong or have the test movements been changed?

 

[Dynon]

I'm not sure whether the test has changed over time - but it's not supposed to go to every corner when it does its test movements. It's supposed to go far enough for you to determine that it's moving in the right direction per your calibration. In short, what you're seeing sounds to be correct.

 

[DonFromTX]

But it DOES go to the full extreme corners in the test. When it gets to the stop, apparently the clutch is then slipping I suppose, since it goes completely to the stop and continues to "buzz" after it gets to each of the four corners.
Has anyone eles experienced this activity during the test?

 

[DonFromTX]

OK, 235 members have viewed this and not made comments. Has anyone else encountered this strange behavior when doing AP Servo testing?

 

[dynonsupport]

Don:

One correction - there is no clutch in a Dynon Avionics servo; we use a stepper motor, so when you exceed its torque limit, it slips magnetically rather than mechanically. We do so so that the servo can be dynamically adjustable and thus can be tailored for each individual installation.

Assuming you installed the limiting bracket, is that what the arm is hitting (prematurely) during the test phase? If so, can you reposition the limiting bracket?

If you're concerned that the servo is exceeding normal range during the test phase, we can take a look at it. Contact Tech Support - support AT dynonavionics dot com or call 425-402-0433.

But it DOES go to the full extreme corners in the test.  When it gets to the stop, apparently the clutch is then slipping I suppose, since it goes completely to the stop and continues to "buzz" after it gets to each of the four corners.
Has anyone eles experienced this activity during the test?

 

[DonFromTX]

It is in an RV12, the plans have us NOT install the limiter brackets on the servos.The test is taking the stick to its limits of movements (up, down, left, and right) built in to the plans.
In the original tests, the stick only went part way to the stops. After V12.0 installation, it does this stop to stop movement.

Don:

One correction - there is no clutch in a Dynon Avionics servo; we use a stepper motor, so when you exceed its torque limit, it slips magnetically rather than mechanically. We do so so that the servo can be dynamically adjustable and thus can be tailored for each individual installation.

Assuming you installed the limiting bracket, is that what the arm is hitting (prematurely) during the test phase? If so, can you reposition the limiting bracket?

If you're concerned that the servo is exceeding normal range during the test phase, we can take a look at it. Contact Tech Support - support AT dynonavionics dot com or call 425-402-0433.

But it DOES go to the full extreme corners in the test.  When it gets to the stop, apparently the clutch is then slipping I suppose, since it goes completely to the stop and continues to "buzz" after it gets to each of the four corners.
Has anyone eles experienced this activity during the test?

 

[dynonsupport]

Don:

In SkyView v12.0, the test portion of the servo calibration was not changed.

One thing that can make it seem like the test is taking the controls to the limits is if the test is started with the controls not in the neutral position. Could this explain what you observed?

It is in an RV12, the plans have us NOT install the limiter brackets on the servos.The test is taking the stick to its limits of movements (up, down, left, and right) built in to the plans.
In the original tests, the stick only went part way to the stops.  After V12.0 installation, it does this stop to stop movement