Hey all,

I’m a relatively new Mavic Mini owner with just under 8 hours of so of flight time so far.

In this post I am going to be asking a question regarding an error I received not too long ago and asking another question on top of that.

So, first off, I have absolutely no idea how to download my log data. I know it’s possible because I’ve seen it from other people, so if someone could point that out to me that would be great! I really want to get this log to see about an error I received recently. About 13ish minutes into a 20 minute flight as I was descending my drone encountered a “Motor Error” and started shaking. The shaking even overcame the gimbal and was visible in the footage afterwards. Immediately following the “Motor Error” and subsequent shaking, my drone hit the ground from about 15ft in altitude. The drone then proceeded to skyrocket up and over a tree. As I was just starting to regain control the drone clipped a branch on that tree before I managed to regain full control. I ended the event with a chipped propeller and a bruised ego and pretty much 0 idea of what happened. Since that incident I have run the drone through 3 full batteries (about 1.2 hours of flight time) and haven’t encountered any issues. If anyone has more information on this error and/or how to retrieve my log file that would be great!

2nd part:

I’m not sure if this is related to the first but every now and then I notice a sort of clipping noise coming from my drone. This mostly only happens when I’m full down stick descending but occasionally during regular forward/backwards flight. It almost sounds like the propellers are hitting each other. I’m planning a shoot that mostly takes place over a river soon and I don’t want to risk it if the noise is something I should be concerned about.

Thanks!

I'm no expert but you can try getting your flight log from your android phone (sorry I only use Android) under:  
Internal Storage > DJI > dji.go.v5 > FlightRecord

Then you can upload it to Airdata, or phantomhelp website to "view" it and share the link here in the forum.

Of course, I defer to any experts here who can provide better directions.

When it comes to your first part you can read all about different logs, what info is in them & how to retrieve them here ---> Flight log retrieval and analysis guide ... I urge you to read through the whole post, but under point 3 you have how/where to retrieve them.

Your second part ... It's pretty well known that the clipping noise comes from the front props hitting the fuselage, this due to a weak front arm design. No official solution have been released from DJI to remedy this but people have on their own reinforced the front arms with old credit cards, plastic spoons or 3D printed hard plastic inserts instead of those soft ones. Others have put on motor covers & by that rised the props just enough to go free. All these actions of course push the Mini over 250 grams.

Hi there, I'm sorry to hear about the issue with your drone. For better analysis the issue, could you please show us a screenshot of the error message in your app? Regarding the noise issue, do you have any video for us to check the details? We'll do our best to help you, thanks.

Hi all. Video of the motor error itself can be seen at 2:35 in this video https://youtu.be/mHjZ128EC_M I did not regain full control until about the 3 minute mark.i also attached a screenshot of the actual error. The error appeared when the drone started shaking.

I’ll look into uploading my log as some point today! Thanks so far!

djiuser_1Wq5h3xPahsY Posted at 3-26 05:00
Hi all. Video of the motor error itself can be seen at 2:35 in this video https://youtu.be/mHjZ128EC_M I did not regain full control until about the 3 minute mark.i also attached a screenshot of the actual error. The error appeared when the drone started shaking.

I’ll look into uploading my log as some point today! Thanks so far!

I think that both errors are related.

The blades hit the fuselage of the drone and that caused the motor error.

Are there any marks on the drone or blades.

grahamjohnson10 Posted at 3-26 06:26
I think that both errors are related.

The blades hit the fuselage of the drone and that caused the motor error.

Nothing that looks like it might be from a propeller hit. I honestly don’t remember if I heard the sound when the error occurred or not.

I’ll get the log file down today so hopefully that may be able to shed some more light on the situation.

Here is the log from that flight. There’s not really much to tell me anything I think. https://app.airdata.com/share/gztIrs

I am wondering if this isn't a case of too much play between propeller journal/screw and the mounting hole. Could have gone into resonance and stalled one or more propellers.

Without the DAT log that gives access to the motor data it's hard to say for certain ... but this do look like a prop failure for the right front one (and the camera shake further indicate this ...). The reason for the flight to ends like it does, with the AC hitting ground is also partly due to a late release of the throttle stick ... & this in combination with an weakend thrust ability (brake in this case) from a prop damage.

If we first look into the stick commands vs. VPS height & Z-speed (in this case descend speed) ...

Were the marker are located in the chart at 839sec full negative throttle (descend) & some positive elevator (forward) are applied. The descend speed is around 2m/s and the height above ground is 12m. At 840sec the sticks are released ... now with only approx 2,5sec left to ground impact, now with a height of approx 7-8m.

At 841,5sec full negative throttle (down) is again applied accelerating the down speed to approx 4m/s ... now only 5m above ground. Approx 1sec later the AC hits the ground with approx 5m/s.

After ground contact all sorts of stick inputs are made which makes the AC to take off again ... & yawing CW while flying away mostly due to stick inputs in panic & response to the yawing (more about the yawing further below)

So this about the piloting of the AC ... to late release of the throttle combined with down inputs by mistake & erratic ones as a response to the AC spiraling up & away ...

All above described out from the log depicted in the chart below (click on it to make it larger)



Then more about the motor error, prop damage & uncommanded yawing.

The error shown in the log's event stream ... the error comes at 837sec



Then below we have all the yawing, rolling & pitching that the AC does from approx 837sec were the markers are in the chart.

The AC starts to yaw CW uncommanded, this together with a roll going into positive direction (which get's really on the positive side after the touch down) ... all this indicates that one of the CCW rotating props have been lost or damaged on the right side ... And that is the front right.



To exact show a prop failure on the right front the mobile device DAT log is needed, the one for this flight have FLY049.DAT in the end.

slup Posted at 3-26 11:22
Without the DAT log that gives access to the motor data it's hard to say for certain ... but this do look like a prop failure for the right front one (and the camera shake further indicate this ...). The reason for the flight to ends like it does, with the AC hitting ground is also partly due to a late release of the throttle stick ... & this in combination with an weakend thrust ability (brake in this case) from a prop damage.

If we first look into the stick commands vs. VPS height & Z-speed (in this case descend speed) ...

Appreciate the reply. I’ll grab that .DAT soon

djiuser_1Wq5h3xPahsY Posted at 3-26 13:31
Appreciate the reply. I’ll grab that .DAT soon

Hmmm, I can’t seem to find the .DAT on my phone.

djiuser_1Wq5h3xPahsY Posted at 3-26 13:34
Hmmm, I can’t seem to find the .DAT on my phone.

Not unusual when it comes to the Mini & the Fly app unfortunately ... then further investigation and proof of what's seen in the TXT log will be impossible.

djiuser_1Wq5h3xPahsY Posted at 3-26 13:34
Hmmm, I can’t seem to find the .DAT on my phone.

If you have Auto Sync enabled in the DJI Fly app it deletes the .DAT file once it's uploaded to DJI.

It's important to disable this so as your device keeps the .DAT files.

It's a shame because the .DAT file holds a lot more info than the .txt  file.

I can state, with certainty, that, in my situation, the mismatched pair of new blades on the front left arm was the culprit. With the blades unbalanced, the arm vibrated in a torquing manner violently at high speeds, especially descending. This vibrating caused the blades on this arm only to strike the body of the drone when the arm was torquing under a high enough load.

By matching the mould numbers (E3) of the new blades on the motor on the front left arm, the vibrating stopped, as did the blades whacking the body.

Although DJI states to replace both blades on a motor at the same time, if those blades come from different packs, it can cause the same problem I experienced.

This may not be your situation or cure, but, if this helps, I'm glad!

Erik713 Posted at 3-27 11:57
I can state, with certainty, that, in my situation, the mismatched pair of new blades on the front left arm was the culprit. With the blades unbalanced, the arm vibrated in a torquing manner violently at high speeds, especially descending. This vibrating caused the blades on this arm only to strike the body of the drone when the arm was torquing under a high enough load.

By matching the mould numbers (E3) of the new blades on the motor on the front left arm, the vibrating stopped, as did the blades whacking the body.

I appreciate the response. When this occurred all 4 motors were still using the factory blades. Once I managed to land it and saw the chipped prop I changed both blades on that motor using one pack of blades as per the manual.

djiuser_1Wq5h3xPahsY Posted at 3-27 12:01
I appreciate the response. When this occurred all 4 motors were still using the factory blades. Once I managed to land it and saw the chipped prop I changed both blades on that motor using one pack of blades as per the manual.[Image]

Ah. Sorry my thought wasn't helpful in your case. I hope you get it figured out soon!!