Need help with CC3D Servo issue
« on: December 11, 2017, 03:04:51 pm »
Hello. I have a cc3d installed on my fixed wing it flies well but after some time there is a weird issue.
When I increase throttle the airleons move towards left and my transmitter input is not effective on it and if it is effective it takes a long time to make it effect and till that my plane crashes.
I have done setup again several times but no effect on it.

Throttle proportional to the airleons leaning towards on direction.

f5soh

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Re: Need help with CC3D Servo issue
« Reply #1 on: December 11, 2017, 05:35:25 pm »
Hi,

Are you flying with Attitude stabilization ?
Try flying in pure Rate stabilization mode if issue still, if Rate flies great you may need to remove vibrations affecting accelerometers.

Re: Need help with CC3D Servo issue
« Reply #2 on: December 11, 2017, 05:47:27 pm »
OK I will try but there are no vibrations.
It flew great with attitude but now it is behaving weird. 8 will post a video in few hours

f5soh

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Re: Need help with CC3D Servo issue
« Reply #3 on: December 11, 2017, 06:17:44 pm »
Wrong Attitude estimation can be vibration or after a while if you are flying circles.
So the most common issue comes from vibrations, in you case while increasing Throttle.
Be sure the Attitude tab > Filtering Accelerometers value is not set to 0 (disabled) but 0.05 or more.

Re: Need help with CC3D Servo issue
« Reply #4 on: December 11, 2017, 08:25:08 pm »
FlySky transmitters have a wiring problem that causes this.  Is this a FlySky transmitter or a clone of it?

Re: Need help with CC3D Servo issue
« Reply #5 on: December 12, 2017, 03:04:26 am »
Yes it a flysky transmitter but this problem did not existed before after some circles in the air and few mild crash and after installing buzzer alarm

Re: Need help with CC3D Servo issue
« Reply #6 on: December 12, 2017, 05:44:38 am »
How to verify if you have this issue, and fix it too.
https://www.rcgroups.com/forums/showpost.php?p=38300831&postcount=1755

Re: Need help with CC3D Servo issue
« Reply #7 on: December 12, 2017, 07:24:41 am »
How to verify if you have this issue, and fix it too.
https://www.rcgroups.com/forums/showpost.php?p=38300831&postcount=1755


Here is the video showing problem

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(Cliff changed video to a youtube.com link to get it to show in forum)
« Last Edit: December 12, 2017, 07:58:15 am by TheOtherCliff »

Re: Need help with CC3D Servo issue
« Reply #8 on: December 12, 2017, 08:16:38 am »
When you move the throttle to zero the I term windup gets zeroed because of Stabilization->ZeroTheIntegral.  That looks like why the servo moves back to center at zero throttle.

I assume you are running the airplane in Attitude mode.

Are you running stock PIDs?

I have witnessed that fixed wing in Attitude mode does not return to level for a few seconds when you release the stick.  It happens every time.  Try running the throttle very low, moving the ailerons and releasing the stick to get the ailerons off center.  Then bank / move / roll the airplane by hand in the direction the ailerons are asking it to go.  I wonder if the ailerons will level back out when the airplane is banked, and eventually in a few seconds the ailerons will be level when holding the wing level.

Your aileron servo looks perhaps too sensitive to me.

There indeed is some small jitter that looks like it is caused by vibration.  I would rebalance my prop carefully and also look for bent motor shaft.

Re: Need help with CC3D Servo issue
« Reply #9 on: December 12, 2017, 08:53:45 am »
When you move the throttle to zero the I term windup gets zeroed because of Stabilization->ZeroTheIntegral.  That looks like why the servo moves back to center at zero throttle.

I assume you are running the airplane in Attitude mode.

Are you running stock PIDs?

I have witnessed that fixed wing in Attitude mode does not return to level for a few seconds when you release the stick.  It happens every time.  Try running the throttle very low, moving the ailerons and releasing the stick to get the ailerons off center.  Then bank / move / roll the airplane by hand in the direction the ailerons are asking it to go.  I wonder if the ailerons will level back out when the airplane is banked, and eventually in a few seconds the ailerons will be level when holding the wing level.

Your aileron servo looks perhaps too sensitive to me.

There indeed is some small jitter that looks like it is caused by vibration.  I would rebalance my prop carefully and also look for bent motor shaft.
Yes I run on stick pid I am still new to these f3 fc

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Re: Need help with CC3D Servo issue
« Reply #10 on: December 24, 2017, 02:26:16 pm »
When you move the throttle to zero the I term windup gets zeroed because of Stabilization->ZeroTheIntegral.  That looks like why the servo moves back to center at zero throttle.

I assume you are running the airplane in Attitude mode.

Are you running stock PIDs?

I have witnessed that fixed wing in Attitude mode does not return to level for a few seconds when you release the stick.  It happens every time.  Try running the throttle very low, moving the ailerons and releasing the stick to get the ailerons off center.  Then bank / move / roll the airplane by hand in the direction the ailerons are asking it to go.  I wonder if the ailerons will level back out when the airplane is banked, and eventually in a few seconds the ailerons will be level when holding the wing level.

Your aileron servo looks perhaps too sensitive to me.

There indeed is some small jitter that looks like it is caused by vibration.  I would rebalance my prop carefully and also look for bent motor shaft.
Problem is still there which made my plane crashed.

It takes too long for servo to get in mean position while throttle is not idle and my transmitter is working fine.
And no major vibrations are there.


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Re: Need help with CC3D Servo issue
« Reply #11 on: December 24, 2017, 06:08:49 pm »
Connect GCS and look at FlightData->PFD when you increase throttle.  Does PFD bank angle jump?  From good to bad or from bad to good?  Probably moving throttle "from above zero to zero" PFD jumps ... and moving throttle to "from zero to above zero", PFD moves slowly (like servo moves).

If it jumps, you might need to recalibrate Attitude->BoardLevelCalibration or just redo all calibrations and see if PFD and servo work as expected.  BoardLevelCalibration should be done with it level, not tail dragger sitting on tail wheel.

Unfortunately, some chicken and egg here.  I haven't seen anyone set up fixed wing stabilization without first flying it manually.  :(  I personally always get it flying in Manual mode, then add Rate mode, then add Attitude mode (adusting different things at different steps).
« Last Edit: December 24, 2017, 07:51:01 pm by TheOtherCliff »