Phantom 2 descending in VRS almost everytime

[simondeman]

Hi everyone,

First of all this is not a case of auto land. This happens to me even when batteries are full (and new).

I've been using my Phantom 2 in Bogota, Colombia for about a year now. I never had any problem flying, even though Bogota is 2600m above sea level.

A couple of months back, I was in the Colombian Amazon region and had a crash (touched some cables I hadn't seen). The crash could have ended really bad, but fortunately the drone was more than OK and I could even fly again the same day.

My problem: recently, I've had many issues descending the P2.
I have to descend really really slowly, otherwise it just gets into VRS and starts descending/falling really fast, out of control. I've had a couple of crashes yesterday because of that. This never happened to me before, although I was descending twice as fast.
I've noticed this happens more when I am flying in Bogota (2600m) or other places where I'm at more 2500m above sea level. At first, I thought it was because of the air density or friction which is less dense in altitude (correct me if I'm wrong), creating a more difficult environment to fly and making the P2 more sensitive.
But it happens almost everytime now, when this never happened to me in the many flights I did in the past at the same altitude.

Could it be that the motors are slowly dying? Would you advise me to replace them?
Could it be that something was "broken" when I crashed in the Amazon region? I've got all the latest firmwares installed and the app tells me everything seems to be ok.

Thanks!
Simon

 

[Hughie]

HI simondeman, welcome to the Forums.

Are you using prop guards? (They are thought to aggravate VRS)

Do you have the latest firmware on your P2? (3.08 limits rate of decent)

"Maximum descent speed set to 0.6m/s when the aircraft’s altitude is less than 10m and descending automatically
(for example in failsafe mode). The maximum speed of descent remains 2m/s in other flight conditions "

 

[simondeman]

Hi Hughie,

Thanks for the quick reply.
I'm not using prop guards.
The firmware is 3.08

I'm attaching screenshots of the Phantom software on my mac. Would you mind having a look and telling me if I'm doing something wrong?
I've only disabled the go home when battery is low, as I prefer to keep control.

Thanks!
Simon

 

[simondeman]

Here are the last 4 screenshots

 

[Mako79]

Firstly, Default your gains. Over sensitivity can cause twitchiness and hinder the behaviour a motor to react.
Also, are you carrying any additional weight?
Can you tell us what FPV gear you have?

EDIT: and why is all your sticks (AETR) NOT centred? They are all to the right.
You should recalibrate in both software. Do the RC1.2 first and then the Phantom Assist > Basic > RC.

 

[simondeman]

Hi Mako

Thanks for the reply.
I've set the gains to default. Is it normal that they automatically switch to these values after I click on the default button?


Regarding the FPV, I'm using a Kumbacam advanced kit: http://kumbacam.com/DJI-Phantom-FPV-Kits?product_id=65

It looks a bit loose on the picture, because I still haven't had time to rearrange it after last crash.
Do you think it's too heavy for the P2?

And lastly about recalibrating the sticks, I'll do that tomorrow first thing. Should I place them on the red mark in the middle then?

Thanks a bunch for all your help. Learning a lot from you guys.
Simon

 

[Mako79]

Oh..
And did you do an advance IMU calibration after the crash?
The IMU (inertia measuring unit) has sensors that can be knocked out of whack after a bump or too. The sensor is for gyros/accelerometer and altitude.
Do the adv IMU calibration on a surface levelled with the horizon and do when the phantom has not been on for half hour so.
Doing it cold will make the sensors calibrate more accurately and faster and guarantee you get the green ticks in 3min or less.
I do mine immediately, Ie. I have the Phantom assist IMU screen ready, phantom plugged in and I run it the moment I turn the phantom on. This will prevent the "MC Temp too hot warning".

Many will argue this point and say the warning is a bug.

 

[mendezl]

post a video of your VRS

 

[Hughie]

Please weigh your Phantom with the battery fitted and post the weight.

 

[crash1sttime]

Should I place them on the red mark in the middle then?

Thanks a bunch for all your help. Learning a lot from you guys.
Simon

Use the phantom RC asst software to calibrate the RC unit first then re calibrate again using the RC tab in the phantom software, stick marks should sit centre line once calibrated

 

[750r]

What props are you running ?

 

[simondeman]

Hi all,
Thanks for the replies.
I've done the IMU calibration and the RC calibration. All seems to be alright now.

Regarding the weight, I'll try to do that ASAP, but I don't have a scale at home.
As for the VRS video, I'll post it soon too. I just need to get my SD card back from my client. Should be able to post something tonight.

One last question, now everytime I turn the P2 on, the Zenmuse H3-3D gimbal does a long vibrating noise (for about 5-10 seconds). Could it be because of the last crash? Can it be calibrated too? I'm afraid the motors might burn if it happens too often.

Thank you all!

 

[simondeman]

What props are you running ?

DJI original props

 

[simondeman]

Hi everyone.

IMU calibration seems to have worked for me.
I have been flying today and noticed the P2 was much more responsive and didn't get into VRS. I'm so happy.

Thank you all for your kind help (even the gimbal vibration seems to have disappeared for some reason)

One last question, is there an option or a way to check the descent speed limitation in the Phantom app? I'd like to make sure it is super slow!

Thanks!

 

[Haze]

dont know how you are getting into VRS on the NEW Firmware, I used to get VRS on old Firmware but learned how to get out and avoid. But I have tried as hard as i can to make the craft go into VRS for Training and i Cant get it to VRS in 3.08+ it just wont go into VRS, (unless in manual mode).