I was very, very lucky ... (birdstrike?) on Mavic 2 Pro

[Ronny St.]

I am sorry for my probably stupid question, but I cannot find the exact meaning of the word 'lug'. I find a lot of meanings but they don't fit in this context for me.
See e.g. Definition of LUG or LUG.

 

[MS Coast]

I am sorry for my probably stupid question, but I cannot find the exact meaning of the word 'lug'. I find a lot of meanings but they don't fit in this context for me.
See e.g. Definition of LUG or LUG.

Think of a bolt with the head end embedded in a solid material so that only the threaded cylinder is sticking out. (There's not generally a head.)

There are lugs on an automobile wheel that lug nuts screw onto to secure the wheel in place.

 

[Yorkshire_Pud]

I am sorry for my probably stupid question, but I cannot find the exact meaning of the word 'lug'. I find a lot of meanings but they don't fit in this context for me.
See e.g. Definition of LUG or LUG.

Photo 13 post 13, it is ringed in yellow, see also photo 10 which shows the mark where the lug was broken off that arm.
By the way the plastic portions of the pivot are lubricated with what is probably a silicone grease, this grease gets onto the surface of the break, I suspect such contamination will be difficult to 100% remove so I doubt gluing the lug back in place is a viable option. If the lug on the left are is broken it is likely stuck in the groove/slot that it slides and you will need to find it and remove it. This ssecond) grove/slot is a circumferential groove/slot that runs around the inner end of the female half of the pivot assembly.

 

[Ronny St.]

Photo 13 post 13, it is ringed in yellow

Overlooked that one, sorry. Thanks for clarifying!

I thought it was something like this:



so, in fact a threaded rod mounted on a surface, but that was not a correct interpretation of me

 

[Yorkshire_Pud]

Those threaded bits would be called "studs", or at least that's their name in British English. I added some more information to post #43.

You can see part of the second groove/slot in photo #10 though it may not stand out so

 

[Ronny St.]

Those threaded bits would be called "studs", or at least that's their name in British English. I added some more information to post #43.

You can see part of the second groove/slot in photo #10 though it may not stand out so

I indeed also found the word 'stud' but now I know it is not quite the same as a 'lug'. I must admit I only knew the slang meaning of the word 'stud' Great to learn more English here!
I hope that 'lug' of the left rear is not broken, if so I will face some difficult DIY repair and will probably better leave that to a professional.
This evening I will not be at home, but tomorrow I will do some actual flying tests in the garden to check out the things you advised me. Fingers crossed

 

[Yorkshire_Pud]

If you do end up sending it in for repair then I would send it to DJI, there prices are reputed to be fair.

 

[Ronny St.]

If you do end up sending it in for repair then I would send it to DJI, there prices are reputed to be fair.

I've been looking already for the address of the official DJI repair center in Belgium in case of needing it. In Belgium there is no official DJI repair center, only retailers that have a repair center, but I found an official in the Netherlands. So if needed, I will go for that one, following your advise

 

[Yorkshire_Pud]

Have you tried emailing DJI to ask about the process and address? I do think the repair centre is in Holland.
If you decide on getting it repaired then I think if you go to DJI's own forum and start a thread, the mods can provide you with a link to get the process started.

 

[Ronny St.]

Have you tried emailing DJI to ask about the process and address? I do think the repair centre is in Holland.
If you decide on getting it repaired then I think if you go to DJI's own forum and start a thread, the mods can provide you with a link to get the process started.

I was now looking at some videos on YT to find out how to remove the rear legs and inspect the lugs. If it turns out to be to delicate I will leave it to a pro if necessary. I first will try out some flights tomorrow to see if I can get more information about something possibly going wrong.

 

[slup]

There is something really odd about this one. When looking at the commanded, current and speed of the left front motor it appears to have lost the prop. And the time integrated gyro data for the first second there is pitching down, rolling CCW and rotating CW - all consistent with left front loss of propulsion.
View attachment 162893
But, then the MP2P starts rotating CCW while continuing to pitching down and rolling CCW. How is this even possible?

At the time when the red gyro change direction & starts to "unwind" value wise CCW what's initially been "wind up" CW, the motor RPM's also stabilize... the green (front left) is maxed out with a minimal amp draw (clearly indicating that the prop is missing), the blue nearly stops (rear right) as an answer to the front left isn't producing any thrust.


The front right (purple) & rear left (yellow) still keep the RPM's up somewhat... but rather uneven. So it's really 2 odd thing's here... the stabilized RPM's when the AC change rotation direction & the uneven RPM between the front right & rear left.

Could any of the the front right or rear left arm been partly folded in the impact (don't exactly know in what direction the arms fold, or if they are rotated out in position or just folded straight out) ?

 

[Ronny St.]

The front right arm was indeed partially folded by the impact (the rear was not), but was partially folded in the normal way one would fold it to pack up the drone. All other legs
Btw do you get these graphs from the DAT file or from the files on Airdata UAV?

 

[Yorkshire_Pud]

@BudWalker 's graphs look those produced by processing the DAT and or the txt flight log with the likes of CsvView CsvView Downloads
I don't remember if DatCon ( at the same website) produces graphs.
@slup 's I am not sure about, the vertical resolution is much higher than I have seen in a CsvView graph.

 

[BudWalker]

@BudWalker 's graphs look those produced by processing the DAT and or the txt flight log with the likes of CsvView CsvView Downloads
I don't remember if DatCon ( at the same website) produces graphs.
@slup 's I am not sure about, the vertical resolution is much higher than I have seen in a CsvView graph.

DatCon doesn't produce graphs. CsvView uses DatCon internally to convert the .DAT to a .csv that CsvView knows how to display.

The higher vertical resolution on @slup 's graphs is due to the larger vertical size of the graph window

 

[slup]

... I am not sure about, the vertical resolution is much higher than I have seen in a CsvView graph.

If you by "high vertical resolution" mean the high negative values on the axis for the gyro... it's normal, that Csvview signal is adding when rotating CW & subtracting when rotating CCW... so if the AC have rotated a lot CCW the value will be high on the negative side.

... And what I showed in post #51 is from the .DAT log in Csvview.

 

[slup]

The front right arm was indeed partially folded by the impact...

And here you mean... when you found it on ground? I mean the initial impact when the AC still was airborne. Or did you see that the arm was partially folded before it touched down?

 

[Yorkshire_Pud]

DatCon doesn't produce graphs. CsvView uses DatCon internally to convert the .DAT to a .csv that CsvView knows how to display.

The higher vertical resolution on @slup 's graphs is due to the larger vertical size of the graph window

Cheers, I'll have to try a smaller vertical dimension to the zoom.

 

[BudWalker]

Cheers, I'll have to try a smaller vertical dimension to the zoom.

Like this

 

[Yorkshire_Pud]

My 'problem' is a wide-screen laptop screen lol so limited screen height in comparison to screen width.

 

[Ronny St.]

And here you mean... when you found it on ground? I mean the initial impact when the AC still was airborne. Or did you see that the arm was partially folded before it touched down?

As it was too away (but well into VLOS) I could not see the individual arms in flight detailed enough, so I cannot say it was partially folded before the descent, sorry. But as it 'clicks' normally in position (folded or unfolded) I suspect it became partially folded during the impact.