P3SE motor failed mid-air and recovered

[rprieto]

HI everyone,

Need some advice here.

Specs: P3SE 2nd hand, with signs of having crashed before. One motor has a dent on the prop screw; I use always the same prop in that position (since the nick created new grooves). Have flown it a few times and it seemed to be flying well.

Problem: Today I went out to sea (I'm a marine biologist and the drone is a work instrument). Did a flight to photograph a marine turtle and when I was returning to the boat i saw the image turning up (see video below) and a message about something in the motor appeared briefly (I cannot remember the exact message). Got a bit scared, aborted a return-home request and brought it back to be hand retrieved. Upon seeing the video, I noticed that additionally to the jerk I saw, there was another one to the end of the video, when I was about to switch the camera off.

I believe one of the motors failed briefly but has then recovered. But it seems it happened at least twice, based on the video. I downloaded the flight log to AirData (can be seen here

) but there was no mention about the 'motor' message.

I tested the motors (without props) and cannot see or hear any difference among them. Also tried to turn them by hand and don't feel any noticeable difference.

Questions:

1) does anyone recognize this behaviour and could it be a defective motor?
2) How could I know which motor is affected?
3) Are P3S motors compatible with P3SE? (I think so, but just to be sure)

Looking forward to hear your thoughts.

All the best to all

rui

 

[PhantomFandom]

Hello,

First of all, wow is that some beautiful blue water there!! Also thank you for providing full details.

Without having looked at the flight data but from your description, my initial rough guess would be that the fault lies with the dent on the prop screw. A picture of that might also be helpful. If the prop is somehow slipping then you can see how that one motor loses thrust and the drone tips in that direction. Luckily it re-engaged and you did not lose the drone. If it was me, I wouldn't fly until that issue gets resolved.

The solution would be to replace the motor. The cost is minimal (about $15 US). It does take a bit of work to replace the motor since you need to take off the shell, un-solder the old motor leads from the ESC and then solder the new motor leads to the ESC. If you're adept at disassembling electronics and soldering, it isn't bad. If you're not good with soldering, I would let a professional do it.

 

[rprieto]

Thank you @PhantomFandom for the prompt and insightful reply. It makes sense. It's not easy to see in the pic but the screw is a bit worn. I will look into this more carefully. If needed, I can change the motor. I have some spares from a p3s that I believe are compatible

Cheers
R

 

[PhantomFandom]

Thank you @PhantomFandom for the prompt and insightful reply. It makes sense. It's not easy to see in the pic but the screw is a bit worn. I will look into this more carefully. If needed, I can change the motor. I have some spares from a p3s that I believe are compatible

Cheers
R

Yes i see the groove and I would not trust that prop shaft.

The P3 series had two different motor types (2312 and 2312A) although I believe the P3S only ever used one model. The two motors look physically different so just make sure it looks the same. Also do make sure you have the proper rotation (CW vs CCW), or you'll have bigger issues than you have now.

 

[Deleted member 62848]

Yip that motor is poop,,every time you screw prop down it will never grab proper and will also kill thread inside prop,,have not seen a motor burred with thread like that,,,,,possibly cause is way to tight on prop thread or incorrect or cross threading when installing prop,,,,yip your very lucky not to be swimming ?

 

[rprieto]

Thank guys for these tips. I was not aware of the two motor types. And yes, I did remember that I ahve to use the proper rotation, but it is good to be reminded to make the idea sink in. I cannot even imagine what would happen if I made that mistake... ZOOOOOM, OOOPP, BUUUUMMM!

 

[Capt KO]

If you download the flight logs, you might get more info from the guys here that read them. Would answer what exactly happened.

 

[rprieto]

If you download the flight logs, you might get more info from the guys here that read them. Would answer what exactly happened.

HI,

Thanks @Capt KO; I did download it and ran through an online decoder, but there was no mention to messages that I could see. But it is a good idea in case the decoder I used is not good. I amigine that it is also possible to detect a jerk from the attitude sensors, but I have no program to plot it.

The dat file (110 MB) is at http://u.pc.cd/vN6italK

best
r

 

[Capt KO]

This might help.

Flight log retrieval and analysis guide

I posted this guide on the MavicPilots forum after the introduction of the Mavic Mini led to a significant increase in pilots asking for help diagnosing events and understanding log files. It may also be of some interest over here since most of it applies equally to other DJI equipment. While...

phantompilots.com

 

[horsepowerphoto]

P3 had 2312 and 2312A motors, as someone else said... The 2312 were the originals, with a cloverleaf base... the 2312A are the upgraded ones with a round base.. Only reason I know is because I went through the pain of trying to find 2312 motors for mine that I crashed... They aren't overly plentiful anymore.

 

[KachemakDiver]

P3 had 2312 and 2312A motors, as someone else said... The 2312 were the originals, with a cloverleaf base... the 2312A are the upgraded ones with a round base.. Only reason I know is because I went through the pain of trying to find 2312 motors for mine that I crashed... They aren't overly plentiful anymore.

Amazon has the 2312 motors.