Holybro Durandal FC Hexacopter ZD850 Crashed

ArduCopter Copter 4.0
1

On 5th Flight Holybro Durandal Hexacopter ZD850 Crashed.
Flying this build for the first time on loiter mode, and after flying for 2 to 3 minutes in GPS Loiter mode. When I move my transmitter Stick to extreme left to move the Hexa to the left then the Frame enter a movement like Pendulam.
Holybro Durandal Hexacopter ZD850 Crashed.

Can anybody tell what went wrong ???
Seems to be GPS gliltch.

But after that Crash I build another quad on this Durandal FC but still it cannot fly on Loiter mode as well

https://drive.google.com/file/d/14cbbpLJNA6__zdm5RNpaPbaovKkbSEz7/view?usp=sharing,%20https://drive.google.com/file/d/152xugn5oDscDVrZEz9qPuIK_E8wkn1yg/view?usp=sharing,%20https://drive.google.com/file/d/17HgjqZBCb76Ldd3sLoaQk42bZfXU59mB/view?usp=sharing,%20https://drive.google.com/file/d/17Ikw9RZ9MjRE6f_ytFMhCbHM60xuW8oZ/view?usp=sharing,%20https://drive.google.com/file/d/1J4ckz83hMWiDRfj4nOkOFDOo52xASEEh/view?usp=sharing,%20https://drive.google.com/file/d/1JdhKFdq2xAnXcspVslCAvT_bE6V9jmOf/view?usp=sharing,%20https://drive.google.com/file/d/1NrWiLlt0Nvkomuxqhpt9SYn3-QOOs2es/view?usp=sharing,%20https://drive.google.com/file/d/1QggskX9B9gji7r9SIZMKZvwRvL420VPv/view?usp=sharing,%20https://drive.google.com/file/d/1RWt3VJeldIp4hmyYR7DiJFV9vuBxbf4D/view?usp=sharing,%20https://drive.google.com/file/d/1b0MfF6nwFHrOWvA-IGyEQ_X_3VA_4ucb/view?usp=sharing,%20https://drive.google.com/file/d/1kPk9q3tMLPUCzwWY-W2Q48O9lLuMq1vb/view?usp=sharing,%20https://drive.google.com/file/d/1kekswUrHvkY8uhHCEpH1PYv7QoKqrtNb/view?usp=sharing,%20https://drive.google.com/file/d/1xMMOQ9qkHlQlS3XF5TNXdF_BKR_ER74w/view?usp=sharing
https://drive.google.com/file/d/1MH8ZA1cTR1AhVHSPywYm4GLxqeCWieP1/view?usp=sharing

2

In the log I looked at I dont see any GPS issue.

The tuning is not good -> pitch and roll are not matching desired pitch and roll well enough.
Then with more stick movements, and the yaw issue shown below, the flight controller cant maintain stability.

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There’s some motor mount twist happening, causing a physical yaw that the flight controller has to fight. This takes away from motor headroom for stability. Motors 1,3 and 6 (CW) are working hard to counteract motors 2,4 and 5 (CCW)
image

Read through the tuning guide
https://ardupilot.org/copter/docs/tuning-process-instructions.html
And then connect the FC to MissionPlanner and press Alt-A on the keyboard, step through the prop and battery info, accept everything it offers to change except INS_GYRO_FILTER. Leave this at 20.
Or download a copy of this spreadsheet and use that:

I would definitely set these:
ATC_INPUT_TC,0.22
BATT_FS_LOW_ACT,2
BATT_FS_CRT_ACT,1
And I would try these to see if the oscillations can be cured before moving on to Autotune:
ATC_RAT_RLL_P,0.12
ATC_RAT_RLL_I,0.12
ATC_RAT_RLL_D,0.005
ATC_RAT_PIT_P,0.12
ATC_RAT_PIT_I,0.12
ATC_RAT_PIT_D,0.005
And these:
ATC_ANG_RLL_P,5.0
ATC_ANG_PIT_P,5.0
Take off and observe for oscillations without much stick input at all. If there’s oscillation reduce all those values by 10% and try again. When the aircraft seems stable and is able to handle some stick inputs, then think about Autotune.

3

Thank you ! Shawn
I appreciate your effort and will likely check the said issue.