Is there a widespread problem with RC signal loss?

[idiogenic]

Hi guys, I wanted to start this thread to discuss whether there may be a widespread problem with certain Mavic having RC signal loss, as I've seen a few threads on it recently and experienced it myself the other day.

My own experience: my Mavic lost RC signal when 14m away from me, whilst I had direct line of sight to the aircraft. My RTH settings weren't configured appropriately (my fault) for the environment and this resulted in a crash with significant damage - but it never should have lost signal in this situation.

My thread on the situation is here.
HealthyDrones log is here.
.DAT file is here.

I have raised a warranty claim with DJI as I believe the aircraft malfunction was the cause of the crash and subsequent damage, but no determination has been made yet.


Here are several more threads with similar stories:
Rc signal lost!!!
New Mavic having RC signal strength problems. Video fine.
13 min into flight 1st satellite signal drops then RC signal lost.
- I wonder if the GPS loss is related? I was flying in an area with poor GPS reception as well. I've seen other reports of the Mavic behaving unpredictably when GPS is lost as well.

I'm not sure if this is a related issue:
RC icon

These episodes of signal loss are occurring in situations where they really shouldn't be happening.

So is there a systemic issue at play here?

 

[CactusJackSlade]

I do not think it is wide spread.... I've had two Mavic units and both worked perfectly... What you see here on the forums is the problems, not people logging in just to say "I had a great flight today". Kind of the nature of these forums - you see the issues people are having, but not the hundreds and thousands of successful flights...

 

[NickB]

When you first get a mavic it's best to calibrate imu as quickly as possible after switching on so the model doesn't get too warm.
Then calibrate the gps in an open area, more open the better.
Then re-bind the model.

I have used this method for 4 models over 3 years with no glitches.

I'm typing this simply because i have seen quite a few people say they just flew their models without doing ANYTHING!

That's bad imho.

 

[idiogenic]

What on earth does IMU calibration have to do with RC signal loss?

 

[NickB]

Where did i say it has?

I just wrote down a procedure of what i do with DJI RTF models when i set them up.

Sorry for bothering!

 

[idiogenic]

Maybe you're posting in the wrong thread? Did you read the first post?

 

[NickB]

Good luck finding the answer....your attitude stinks btw.

Have a great day

 

[idiogenic]

So does your reading ability mate.

 

[NickB]

There's the attitude again

 

[storemaster]

Seems someone had a bad start this Monday ;-)

 

[armoredsaint]

Someone has a case of the Mondays.

 

[rydfree]

DJI should start a thread "Is there a widespread Problem of new pilots not setting up the AC before flying ". It would be a much longer thread than any here ,LOL.

 

[Wacker2611]

When you first get a mavic it's best to calibrate imu as quickly as possible after switching on so the model doesn't get too warm.
Then calibrate the gps in an open area, more open the better.
Then re-bind the model.

I have used this method for 4 models over 3 years with no glitches.

I'm typing this simply because i have seen quite a few people say they just flew their models without doing ANYTHING!

That's bad imho.

Nick, sorry everyone's piling in to you, but that's just bad advice with this craft. The Mavic is a different animal to previous DJI consumer drones, and you should certainly not calibrate the IMU out of the box. It's been set up perfectly at the factory. Personally, I also wouldn't mess with the compass either, unless the app asks you to.


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[NickB]

Lots of conflicting theories on this one if you search.

I like to calibrate my stuff when i get it, that way i know it's been done, i am an rc enthusiast and have been flying with gyro assisted aircraft for 8 years.
If the gps was calibrated in china i sure as hell would re-cal it for where i live in UK. I'm sorry but i don't agree with not doing it whether the app says otherwise.

 

[Wacker2611]

Fair enough each to his own! We'll agree to differ then![emoji6]


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[triumphrider]

+1 one on not calibrating anything unless notified by the DJI Go App it was necessary. I've travelled back and forth between New York and California and haven't had any issues with the Mavic. If it ain't broke, don't fix it.

 

[mfarris2]

I agree with Nick. They may have the IMU calibrated perfectly in China. But I'll bet the big lift that loaded the cargo container onto a ship,..or the fork lift that lifted the pallet into the cargo hold of a plane was not to gentle. Or when they loaded it onto the vehicle that delivered it to your home. (Think tossed boxes) As far as calibrating the compass,.....differences in magnetic fields can make a big difference. Think power lines, above or buried. And then of course the magnetic earth is different in different parts of the planet. It can change strongly in as little as 50 ft.
This is your expensive toy. The few minutes that it takes to perform the IMU calibration, and the few seconds it takes to perform the DJI dance at each new flight location is pretty cheap insurance for that toy. If you choose to not perform these calibrations,.....well,............thats a roll of YOUR dice.


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[Wacker2611]

Again, it's up to you what you do with your Mavic. If you want to calibrate it every time you fly, go ahead. But....As far as all your reasons for recalibrating the IMU is concerned, I assume then that you recalibrate it every time you fly? Reason I say that, during any normal flight your craft is going to get knocked about like crazy in the air and on landing so by your logic you would need to calibrate it each time, yes? As far as the compass is concerned, again, if you were near power lines,rebar etc etc the app would tell you to calibrate so you would just move away from any potential interference until the warning goes away. Either that or pack up and move somewhere else. If the craft is still telling to calibrate in area that you know has no interference then, yes it should be done!
My point is, once you have a good calibration, stick with it, unless you want to heighten the chance of getting a bad one by constantly resetting everything. This is proven best practice and not conjecture.


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[mfarris2]

What I read was to calibrate the IMU as soon as you get it out of the box. This is because of the shipping it went through to get to your actual location. I do not believe anyone would argue that shipping companies do not necessarily have your drones best interest at heart. Once you have calibrated the IMU at your home,....you should not have to calibrate the IMU again. (It is assumed you will take care of your drone and not toss it around) Of course if you have a crash,....then after repairs,...I would calibrate the IMU again. Tossed around in the air,...does not bring physics into play. Hard ground landings would. Power lines (40,000+ volts) puts out a magnetic field that can be over 1/2 a mile out. You could be far enough away that you are not getting a magnetic field disturbance,....yet,.....that field could of changed from the last calibration field.
So in essence,...what I am saying and agreeing with is: 1) Calibrate your IMU upon arrival of your drone ONCE,....unless involved in a hard landing or crash. 2) Calibrate as is instructed in the DJI video's your compass at each new flight location.
And as stated in my previous post,.....this is your toy. No one is following you and going to arrest you if you choose not to perform the compass calibration. (Maintenance). But if you ever do have a crash because of compass issues,....it would be no ones fault but your own.
IE,....my cars run fine,....but after so many miles I rotate tires,...change oil,....wiper blades, batteries, etc. Car might of been running fine,....but I prefer to perform maintenance to be on the safe side and not broken down on the side of the road. No one forces me to do this,.....I just prefer to take the time to be sure!



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[Wacker2611]

Yup, totally fine. We'd better sign off as we've managed to sabotage the op's post!

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