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Old Jan 17, 2015, 07:18 AM
diy heli maker
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Poland
Joined Sep 2004
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X8 Wookong M gain problem

Hi.

Here is my new multirotor setup with Wookong M autopilot and camera gimbal/payload.

For a test filght i have been using a landing gear with dummy weight payload(AUW 8kg) and it has been behaving perfectly and smooth with basic gain at 150 or even over 200(yaw and vertical at 130) without any oscilation.

With the shown gimbal/camera payload(AUW 10kg) which is mounted on a vibratopn isolators lower than dummy payload i'm getting small oscilation even at 30! basic gain and 70 for yaw/vertical. At 100 basic gain it oscilates lake crazy. At this low settings there is really not a lot of stabilization.

I'm using KDE4215XF-465 motors with tri-blade folding DJI 1552 props and Hobbywing Xrotor 50A ESC.
All propellers are balanced.

Do you have any idea what is causing this problem?

Could this be because of soft DJI 1552 plastic blades? If so why am i not seeing any problems with 2kg less AUW? Has anyone experienced any dramatic gain changes after switching from CF to soft plastic propellers like these foldable ones?
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Old Jan 17, 2015, 06:04 PM
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Joined Feb 2006
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The dampers has relation, may be too soft. If the sakes are up-down at about3-5 sakes per second then reduce altitude gain.
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Old Jan 17, 2015, 06:45 PM
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Using a soft propeller can always cause problems with any aircraft type, especially as weight and/or RPM increases. If a blade lacks torsional rigidity thrust efficiency is lost, vibrations are introduced, stability issues can arise, and the FC has to work harder to deal with all of that.
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Old Jan 18, 2015, 10:04 AM
diy heli maker
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Poland
Joined Sep 2004
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So far i have tried changing the payload dampers from ultra soft to stiff, different IMU to CoG location settings(Z and X axis) and medium/high ESC timings.
There has been no change in behaviour, still gain related oscilations/wobble visible...
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Old Jan 18, 2015, 06:19 PM
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I bet for altitude gain.
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Old Jan 18, 2015, 07:34 PM
diy heli maker
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Isn't attitude gain related to reaction to stick movement(stick authority) only? I had it set to 55.
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Old Jan 18, 2015, 09:43 PM
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nice X8, join us in the X8 facebook page and post your problems too... maybe somebody can help...

https://www.facebook.com/groups/311967642341884/
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Old Jan 19, 2015, 06:10 AM
diy heli maker
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I have also tried wooden Xoar 15x5 props, still the same.
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Old Jan 19, 2015, 09:47 AM
diy heli maker
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Poland
Joined Sep 2004
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I have attached a short video:
Sequence 01 1 (0 min 18 sec)


You can clearly hear the motor oscilations and see the arms moving up and down(especially the front arms) and camera gimbal wobbling. This was with pich/roll 60 and yaw/vertical 70 basic gain. Attitude gains were at 55.

I have already tried:
-recalibrating compass
-recalibrating each ESC
-firmware reinstall
-wooden xoar 15x5 propellers
-harder and softer camera gimbal dampers(even completely tightened up with zip ties)
-different motor timings
-different IMU/GPS positions(Z and X axis) in configurator
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