Two Tilt Servo angle is different with same PWM range

ArduPlane VTOL Plane
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1

Hello, Below is detail of the problem as per video
(Freeman Tilt Servo VTOL.mp4 - Google Drive)

[1] Two Tilt Servo’s PWM Range : 1050~2000(Two servo pwm range was same)

[2] Two Tilt Servo’s action in Manual mode : The motor become straight well

[3] Two Tilt Servo’s action in QStabilize mode : One of the motor does not reach to upright straight, as per the video.
only one motor reach to upright straight angle.

[4] Result :

Servo pwm value range was same(1050~2000) but the two servo’s tilt degree was different.

so I adjust “TiltMotorFrontLeft” to 1000~2000 and the problem was solved.

PWM range is different, but actual tilt servo degree is same.

two servo is same model.

I wonder This solution is right method.

Have anyone ever experience this symptom?

I want to get opinion about this.

2

We hade same issue. 50 pwm should not be a problem. We had more than 200pwm diffrence after crash, not flyable and had to change it.

3

Sounds very dangerous. maybe servo was damaged due to crash

4

My tiltrotor crashed after this symptom, with servo issue.

5

I’ve setup a couple of VTOLs and most of the time they will not have identical PWM range. I just adjust the endpoints independently to reach back enough so prop doesn’t strike wing in vtol mode, and straight forward in FW mode. Then adjust the Q_TILT_YAW_ANGLE so it’s perfectly vertical in VTOL mode. This is the documentation I followed: QuadPlane Setup Tips — Plane documentation in the “Tilt Rotor Setup” section.

6

Thank you for your answer.

I can accept PWM min or max can be different,

but I want to comfirm that PWM “range”(not min or max position) can be different

7

Yes, the PWM range can be different due to the tolerances of all components. Most normal servos have not a high grade processor unit with an low tolerance xtal but simple RC timer.

8

Oh thats very intersting.