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

The 1st thing you should have done before attempting Autotune is to follow the Tuning Process Instructions for your craft:

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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.


: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.


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.


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.


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:

Thx in advance

Access denied to that log file
But you could try these Loiter settings for something a little more aggressive than defaults:

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