Large quad autotune crash

Hi everybody,
I built my 650 quad with pixhawk1 autopilot. Total weight is 4kgs,6s battery 12000mah, 15 inch propellers, and 340kv motors. I took off smoothly for about 10 meters and it was very stable but as soon as i switched to autotune, it began to wobble crazily and ended to a crash.
Please may someone has same problem may help me with log reading and possible causes.
Thx in advance.
Here is the log file link https://drive.google.com/file/d/1ZjAVNNvtu_1bLFHqcge1Uq1NpnGf4MG2/view?usp=drivesdk

The 1st thing you should have done before attempting Autotune is to follow the Tuning Process Instructions for your craft:
https://ardupilot.org/copter/docs/tuning-process-instructions.html

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Thx for your reply, just for undertsanding, did the log show that pre tuning had not been done or just as a general rule before autotune?

I don’t see any evidence it was done. I usually look at the 1st parameter listed in the guide (MOT_BAT_VOLT_MAX/MIN) and assume that if you didn’t get to 1st base you never reached home plate :grinning: It all looks like default to me.

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:smile: thx, i will follow the tuning guide and check the parameters I had set. But from now on, I have a fobia of autotune, i think i will check everything and do later a manual tuning.
Best regards.

No reason to fear autotune. It’s a far safer way to tune than manually in my experience. Many of us have made the mistake of doing autotune first, without getting a decent starting point as the wiki explains.

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Yes, exactly. Autotune commands very aggressive pitch/roll so stability has to be present 1st. Years ago, funny to say that, when some of the tuning parameters didn’t exist Autotune was an iffy proposition IMO. I had better luck with manual tuning. That was good experience but Autotune today is darn good.

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You are right, none of the parameters was set :face_with_hand_over_mouth:, the crash results were a broken arm and two legs. I work now as a drone orthopedist to repair them. I will follow the tuning process and I hope I won’t be a surgeon after next autotune :smile:.

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"0.55 for 5 inch props, 0.65 for 10 inch props, 0.75 for 20 inch props. "

What setting does one use for 9 inch props, Just the 10 inch settings?

^^ This is a great plugin for MP that automatically calculates values based on the tuning guide. Just an FYI, when it asks for screw size it is looking for the prop diameter - 9” in your case.

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Thanks for the tip! I’ve been using the @xfacta spreadsheet which is also really handy.

No problem! I believe the plug-in was built based on xfacta’s spreadsheet.

I downloaded the plugin, extracted it into the plugins folder in mission planner. Started the software, connected the pixhawk and pressed ALT+A but nothing happened. The plugin was not launched. What might be the problem?

Copied to here?Update Mission Planner to latest Beta from the Help Screen.

Plug ins

Yes I did, and I tried different versions of mission planner! I don’t know if the problem is windows (win10) can’t run c# code.

Hi again,
I used xfacta spreadsheet to set initial parameters for autotune and set autotune agressiveness to 0.075 and accomplished the autotune process without any problems. But i feel the quad does not respond well when in loiter mode as I release the sticks. Please may you check the logs and PIDs and give me advise for better performance.
Logs link: https://drive.google.com/folderview?id=1gcZ_ckOM3yAu17y6PS7IM1TQHEf9fBBb

Thx in advance

Access denied to that log file
But you could try these Loiter settings for something a little more aggressive than defaults:
LOIT_ACC_MAX,600
LOIT_BRK_ACCEL,300
LOIT_BRK_DELAY,0.3
LOIT_BRK_JERK,300
LOIT_SPEED,1250

Thx for your reply and I am sorry for the link. It is ready now for download.