Mavic Mini Dragged away mild wind

[sar104]

@sar104 Let me clarify I’m not saying there are not issues I’m just not seeing them other than in the data you have
posted about. I do not doubt what you are seeing in the files.
I do trust what you say.

Understood - that's what I assumed you meant. It never occurred to me that you might doubt me. That never happens¡

 

[BLACK314]

I have found if I leave my mini in The case and then fly after a few days I get the error on my first flight. I land. Download my videos. Watch them. Have a coffee then head out for another flight. Then no error. This happens often and I think it’s the way my props sit in the case and warp a bit due to the storage. After the AC sits out fo the car the props slowly get back to their proper form. Then I have no issues. Just my observation.

 

[Legendberry]

I had the uncommanded descent issue and DJI recommended I return for analysis. Didn't change props and I didn't get around to sending back for a few weeks and kept flying around 25 times without getting the error again. Eventually I sent it in as I couldn't fly confidently over water any more. DJI got it did a test flight and said its fine we will just check the flight log and send it back. The next day they checked the log and said we will replace your drone with no explanation of the issue.
So while under warranty DJI will replace but after that we're on our own... I signed up to the DJI Care thing mainly so I can extend the warranty period

 

[the-bunker]

I’ve been experimenting with taping up the front arms in an attempt to stop my props hitting the AC body. What I have found on the front arms is varying the stiffness/ flex sets up a resonant frequency that manifests in the propellers visually deforming them approx 5 - 7mm in the vertical, when I remove the tape the Mini hovers without issue. May be completely unrelated but it was an interesting observation.

That is interesting - my Inspire 1 developed a serious resonanting\vibrating arms issue. DJI replaced it. The trouble with the Mini is it's pretty flimsy - I can easily see how resonance\vibration could cause loss of performance.

Just an idea - has anyone who experienced the problem tried flying backwards ?

 

[slup]

...Just an idea - has anyone who experienced the problem tried flying backwards ?

Yes ... that have been seen as a working action in some cases, to get some heading speed into the right direction.

 

[mgste]

Hi,
My Mavic mini got blown away by a very mild wind (8-9 MPH) and I could not control it until it crashed.
I was trying to fly against the wind full throttle in sport mode..

What is the problem? Any opinions?

Here is the link to my crash's video:

Cheers,
Bardia

The problem with the propeller theory is that I've seen people experience uncommanded descent events, saved the drone & didn't understand what actually happened & flew days later without problems ... either this with the props only are part of the problem or that they are deformed only to the verge of not being able to sustain pitch/lift ... or something else.

But this is definitely a design flaw ...

Further more @m80116 ... to diagnose those props from those pictures is impossible I would say, but I agree that a prop change should be done ... but as we have seen before ... the problem will come back.

My rear props were bent when l checked yesterday, l unfolded the arms and left it. Today the props are now straight. Perhaps the plastic returns to its original form when left.

 

[Fallen]

Just a thought about what might be causing these uncommanded descents. Warped props are causing the motors to constantly run at a higher rpm. When strong wind is encountered they cant spin fast enough so AC applies max power. After a few mins of max power heat builds up in the ESCs causing more power loss and crash. Do these uncommanded descents usually happen after the AC has been running at full power for a few minutes?

 

[BudWalker]

Just a thought about what might be causing these uncommanded descents. Warped props are causing the motors to constantly run at a higher rpm. When strong wind is encountered they cant spin fast enough so AC applies max power. After a few mins of max power heat builds up in the ESCs causing more power loss and crash. Do these uncommanded descents usually happen after the AC has been running at full power for a few minutes?

It seems that these uncommanded descents do occur in the latter stages of a flight. But, the data suggest they are unrelated to ESC temps.

At around 450 secs the ESC temps are the highest but there are no uncommanded descents. Later, at around 900 secs there are are uncommanded descents yet the ESC temps are slightly lower.

 

[sar104]

It seems that these uncommanded descents do occur in the latter stages of a flight. But, the data suggest they are unrelated to ESC temps.
View attachment 98112
At around 450 secs the ESC temps are the highest but there are no uncommanded descents. Later, at around 900 secs there are are uncommanded descents yet the ESC temps are slightly lower.

And in any case - it's not clear what effect the ESC might be having. When these problems occur the motor speeds are generally at or around maximum, and so the ESCs are obviously not the limiting factor.

 

[Fallen]

And in any case - it's not clear what effect the ESC might be having. When these problems occur the motor speeds are generally at or around maximum, and so the ESCs are obviously not the limiting factor.

Pardon my ignorance, I'm not familiar with DJI hardware and software. The mini is my first dji product. Is there some sort of feedback from the motors confirming that they are running at full speed when this happens? Could the flight controller be sending the command to run full speed, but somewhere down the line it gets corrupted?

 

[Fallen]

It seems that these uncommanded descents do occur in the latter stages of a flight. But, the data suggest they are unrelated to ESC temps.
View attachment 98112
At around 450 secs the ESC temps are the highest but there are no uncommanded descents. Later, at around 900 secs there are are uncommanded descents yet the ESC temps are slightly lower.

Thanks for posting that flight data. If the ESCs aren't the problem, I wonder if cheap build up inside the shell could be causing something else to malfunction.

 

[slup]

Pardon my ignorance, I'm not familiar with DJI hardware and software. The mini is my first dji product. Is there some sort of feedback from the motors confirming that they are running at full speed when this happens? Could the flight controller be sending the command to run full speed, but somewhere down the line it gets corrupted?

All are in the mobile device DAT log ... during uncommanded descent incidents the log shows the rear motors up around 16000 rpm (max) & this with a command rate of near 100% ... meaning it want's all, gives it all & gets all.

 

[sar104]

Thanks for posting that flight data. If the ESCs aren't the problem, I wonder if cheap build up inside the shell could be causing something else to malfunction.

The problem clearly starts with the rear props. With the motors spinning at max and the aircraft still descending, it has to be lack of thrust from the props, which means they are deformed. And it's possible that if, for whatever reason, the motors initially spin up that fast, then that itself leads to enough extra deformation of already marginal props, causing the problem to manifest itself.

 

[Andym123]

Hi I’m a bit late with a reply to this post but wanted to share my experience. I too have experienced issues with my mini. All was ok for a month then I started to get the uncommanded descents, though this was in a no wind situation at low 20 ft height. This only happened when going forwards, all other directions were ok, as was ascent and and descent. I suspected this may be the props from the way it was happening and also advice gained online but as my mini was under warranty I sent it for analysis. Unit got replaced with explanation of motor power issue caused crash. Basically what I’m saying is try replacing the props 1st if not send it in for checks under warranty if applicable.

 

[FoxhallGH]

I don't own a Mavic Mini, but after reading this thread - if I did - I'd be buying a set of carbon-fibre props for it ASAP!

 

[RayKelly]

Hi,
My Mavic mini got blown away by a very mild wind (8-9 MPH) and I could not control it until it crashed.
I was trying to fly against the wind full throttle in sport mode..

What is the problem? Any opinions?

Here is the link to my crash's video:

Cheers,
Bardia

Sorry you crashed. Glad you got it back though.

 

[DMcL0930]

Sure I will do so.
Thanks a lot for your help.

I've been flying a Mavic Mini for a month, and have had this happen to me twice when the winds were low. It could not make any headway and it just came down......and posting wind warnings as well as Max Power. It would not respond to any controls......and just landed. Worried about this because it's impacts on how and where you can fly this drone.

 

[DMcL0930]

Just a thought about what might be causing these uncommanded descents. Warped props are causing the motors to constantly run at a higher rpm. When strong wind is encountered they cant spin fast enough so AC applies max power. After a few mins of max power heat builds up in the ESCs causing more power loss and crash. Do these uncommanded descents usually happen after the AC has been running at full power for a few minutes?

What about motor covers? Could that be a cause of temp build up? I installed these and have had two "uncommanded decscents".

 

[sar104]

What about motor covers? Could that be a cause of temp build up? I installed these and have had two "uncommanded decscents".

It's not a temperature problem.

 

[Andym123]

What about motor covers? Could that be a cause of temp build up? I installed these and have had two "uncommanded decscents".

Just a thought about what might be causing these uncommanded descents. Warped props are causing the motors to constantly run at a higher rpm. When strong wind is encountered they cant spin fast enough so AC applies max power. After a few mins of max power heat builds up in the ESCs causing more power loss and crash. Do these uncommanded descents usually happen after the AC has been running at full power for a few minutes?

No mines was doing it as soon as it went in the air, and as mentioned only in forward flight.