Solo duty cycle?

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Damien

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Flew 35 batteries today (average 30% remaining). While landing after the last scheduled flight a motor appeared to fail and she was slungshot into the desert dust, gimbal taking the first impact then flipped and the motors ingested the gritty dust. Complete write off in terms of gimbal and motors (edit: gimbal rescued!). I have been having difficulties due to the dusty atmosphere with two gimbal failures on this job, and i assume that was the culprit of the motor failure, but is it also possible that the amount of flying in one day alone could also cause a motor failure?

I don't yet have the knowledge to interpret the log data, never had the need before, but if anyone wants to take a look I can send it.
 
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XevetS said:
Was that back to back? If so that's 7 hours of flight time were the motors smoldering before the last flight or what?
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Between 3 to 8 flights back to back, pack up, move... 6 moves in the day, first flight 0630, last about 17:00. At the last point on the third last flight the sound was strange for a few seconds as it ascended. Fail occurred 10 meters above my head on descent, unfortunately I just dipped my head at that point to see the landing pad briefly, Solex screen said stabilise, can't remember what it shouted, looked over my head and saw it enter the sand like a missile

I remember the 3DR team said they ran solo on a tether for multiple days, who knows if that's true.
 
It never really occurred to me that there could be too much flying in a day, had many dozens of days similar, although 35 happened to be my record. I still don't think so, but just thought I'd put it out there to find an answer
 
Did you lube the motor bearings at any time? Don't know if that caused your problem but it wouldn't hurt especially in a dusty environment.

As long as the motors didn't overheat I don't see a problem running for long periods of time. Unless the stock motors just can't take it.o_O
 
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Maddog said:
Did you lube the motor bearings at any time? Don't know if that caused your problem but it wouldn't hurt especially in a dusty environment.
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I hadn't thought to ever lube them, didn't know you could.
 
Learn something new everyday! I'd better try to track down an applicator
 
XevetS said:
There is a thread here https://3drpilots.com/threads/do-you-oil-your-motor-pods-what-oil-do-you-use.4943/
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Great thread, but I have changed my thoughts on oiling bearings, fwiw. The top bearing without question will end up being a dirt magnet once lubricated. Unfortunately followup lubing will flush the fine dirt further into the bearings.

With that said, replacing bearings is a longer term solution and worth the effort. My opinion, adding lube is only buying you time till you can replace the bearings, nothing more. Couple of threads on bearings and replacement here on the forum.
 
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RichWest said:
Unfortunately followup lubing will flush the fine dirt further into the bearings.
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That's what my gut feeling is with regards to dirt. Seems I'll have to read up and decide if it's worth it. Nearly all my work is in fairly dusty environs
 
Before getting out of the consumer drone business 3DR demonstrated a tether for Solo. They claim that they flew for ~38 days straight (24 hrs per day) until they had to take it down for a trade show.
 
andrew.baker.142 said:
Before getting out of the consumer drone business 3DR demonstrated a tether for Solo. They claim that they flew for ~38 days straight (24 hrs per day) until they had to take it down for a trade show.
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Yeah I was thinking about that today, for that reason I had never worried about its duty cycle, but now that I think about it, at hover in a protected environment, there's little to no strain on the motors. My last 8 flights, 10 actually as I had to repeat 2 I think, we're back to back in winds most wouldn't fly in, landings were quite tricky. So maybe that could have an influence in my situation.

Does anyone know if overheating can be detected in the logs? I guess if it were dust accumulation then you'd see a progressive decline in performance over time, while overheating might become apparent just within that hour.
 
Damien said:
Yeah I was thinking about that today, for that reason I had never worried about its duty cycle, but now that I think about it, at hover in a protected environment, there's little to no strain on the motors. My last 8 flights, 10 actually as I had to repeat 2 I think, we're back to back in winds most wouldn't fly in, landings were quite tricky. So maybe that could have an influence in my situation.

Does anyone know if overheating can be detected in the logs? I guess if it were dust accumulation then you'd see a progressive decline in performance over time, while overheating might become apparent just within that hour.
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Overheating detected, no not really. However, a skilled log dude might be able to look at the vibrations and board voltage (maybe) to come up with a similar conclusion you did regarding dirt. Maybe.
 
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RichWest said:
As odd as this may sound in today's high-tech world, a hand can sense heat fairly accurately....;)
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Yeah I'll be checking that in the future! Though even when she crashed, while I was too flustered to think of it as I watched some of the props continued to spin haphazardly an inch down in the dust, I did manhandle the whole craft in the minute after with my bear hand to remove as much dust as I could and didn't notice anything untoward. But yes, I wasn't looking for it specifically.
 
carpy said:
Overheating detected, no not really. However, a skilled log dude might be able to look at the vibrations and board voltage (maybe) to come up with a similar conclusion you did regarding dirt. Maybe.
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One day I hope to become a skilled log dude, I work with similarly complex and correlated data so I should be able to get my head around it, but at the moment I'm a clueless nube.
 
Damien said:
One day I hope to become a skilled log dude, I work with similarly complex and correlated data so I should be able to get my head around it, but at the moment I'm a clueless nube.
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Agree--I'm no expert either.
Here's my workflow to get you started (Others can chime in as they may have a different/better approach.):
1. Download/ID the correct DataFlash log for your flight in question.
2. In MP from DataFlash Logs tab, Create KML + gpx files. This will create a kmz file you can "fly" in Google Earth to isolate the "leg" in question. Also, a param file is created.
3. In MP, PX4 .Bin to .Log. This will create a text file you can import as a spreadsheet so you can sort, etc. Use comma (,) and colon :)) for text delimiters.
4. In MP, try Auto Analysis. This might clue you in a little.
5. Finally in MP, Review a Log.
 
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RichWest said:
Great thread, but I have changed my thoughts on oiling bearings, fwiw. The top bearing without question will end up being a dirt magnet once lubricated. Unfortunately followup lubing will flush the fine dirt further into the bearings.

With that said, replacing bearings is a longer term solution and worth the effort. My opinion, adding lube is only buying you time till you can replace the bearings, nothing more. Couple of threads on bearings and replacement here on the forum.
Click to expand...
So are you saying you should NOT lube bearings- just replace when they start to fail?

How bout cleaning the bearing before oiling with a spray cleaner like that used for electronics? evaporates and leaves no residue,
 
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