First Phantom Crash today -- Some questions

[Creek.Jumper]

Well, after a week of trouble free flying, I tried to fly through a path in a wooded area...I underestimated a low branch and...Flip!

Not to bad, it fell about 6 - 7 feet. Strange, its a phantom 2 and the battery was ejected?

I plugged the battery back in, had some red lights. After awhile they seemed to go away and flash green.

Some questions---

1. Is it normal for the battery to be ejected?
2. What were the red lights?(i'm in naza mode)
3. I was flying in a field and got a gps lock. In the forest the quad felt different...is this because of loss of GPS? The lights were still green.
4. The phantom has dust all over it from the crash. whats the bwest way to clean it
5. anything I should check before next flight?

 

[Great Pumpkin]

1. The battery popped out in two of the three crashes I've had.
2. The red light said you had lost connection, but turned green when connection was regained.
3. The trees could easily have blocked out GPS signals from satellites near the horizon.
4. See other threads for the many suggestions about cleaning. Mild soap and water seem to be preferred.
5. Always check everything after a crash, especially IMU. Look for cracks in the plastic shell. Be sure that motors work nicely. Check the props for dings and cracks. More seriously, you may have to take off the shell and check all solder connections. Next time you fly you must recalibrate your compass.

 

[QYV]

I'm sure others will respond but here's my take:
1) yes. it's happened to me a couple times
2) learn your Naza Mode blink codes. red should mean it has less than a minimum number of satellites it wants for GPS-lock (I think 6?)
3) I've heard that if you're in Naza mode and it loses GPS-lock, the Phantom can't use GPS to hold it's position so whether the computer actually switches to ATTI or it just feels like ATTI... it'll fly like ATTI **
4) compressed air duster thingy for dust, I use a damp cloth on the shell for smudges
5) IMU calibration in Phantom Assistant software, possibly compass re-cali

** ATTI flight: since it can't hold it's position with GPS, the Phantom will "drift" like with the wind or more importantly from your movements. if you were pushing forward so it was moving forward and you release the throttle... rather than the Phantom stopping (like in GPS mode) it will continue to drift forward until you apply counter-thrust to stop. Naturally it can get pretty complicated if you're moving in several directions laterally and/or rotating

 

[Creek.Jumper]

Thanks all. I cleaned it up, re-calibrated. Will take it for a fly as soon as I can.

One thing I find funny - Would the lights not blink different it GPS was lost?

 

[ProfessorStein]

Yes. Even if your Phantom automatically entered ATTI on it's own during flight (ie - if satellites fell below 6 and/or it lost it's GPS lock) it should have shown yellow LEDs rather than green, as it does when you manually switch it.

EDIT: hold on... this might not be accurate. I know I've been in the air and fell below 6 satellites, and all it did was switch to green with a series of reds. So at what point it switches to full yellow, I don't know. I'd have to test. But, either way, yes, your LEDs would flash "differently" if you lost your GPS lock. Whether that's "green-red-red-red" or "yellow-yellow-yellow-yellow" is the question.


I've had a couple of pretty soft crashes and the battery has ejected every time. Does really make me question the latch mechanism.

As Great Pumpkin said, the red lights you saw were your Phantom going back to square one on your start-up sequence. Since the battery came out, your Phantom lost everything - all it's GPS locks, home locks, etc. So, when you plugged the battery back in, it had to start over as if it was the first flight of the day. Red lights are perfectly normal on start-up and simply means that you currently have less than 6 satellites in view. As the GPS warms up, and more and more satellites are locked, those reds should turn to green when it's finally got 6 or more. You'll see this during any start-up, but of course the reds will last longer if you're starting up in an area where it takes longer to find satellites (ie - under trees, or other obstructed area)... whereas, if you're starting up in a wide open field, the reds might turn to green so fast that you hardly notice them.

 

[N017RW]

One could argue that battery ejection is a good thing as it removes power and prevents possible electrically related damage.

 

[ProfessorStein]

Yep. That's one way to look at it, N017RW. Though... the flip side of that is it might not prevent electrically related damage at all... since as the battery is wrenched away from the power contacts, there's a decent chance that arc'ing and/or shorting will occur, just as it could when you unplug the Vision camera while the board is powered up (to site an example that we're all too familiar with).

 

[N017RW]

In my CP heli days the batteries have/had no switches and arced every time they were connected.

Never say never, but... I never had an issue.

 

[Creek.Jumper]

Hi All.

I did the IMU calibration, went for a fly today, and had some trouble keeping the quad straight.

There was a bit of a wind (3Km with 10Km gusts according to smartphone). When I would go forward in GPS mode it would veer off to the side, I had to make several steering adjustments (I was not in ATTI mode, and had a GPS lock). Is this normal for this amount of wind?

 

[Meta4]

No ... the Phantom can handle 20 knots (almost 40 km/h) easily.
It wouldn't even notice 10 km/h

 

[Creek.Jumper]

Any idea than what could be the issue? I had the crash (seemed minor) I did and IMU calibration. Not sure what else to do..

 

[ProfessorStein]

After the IMU calibration, did you happen to recalibrate the compass? That would be the next step... and significant drift in GPS mode can certainly be a symptom of a compass that needs calibrating.

Another possibility is one or more of your motors has debris in their rotors (especially seeing as how you had your crash), making your Phantom unstable. If you feel up to it, try opening them up and give each of them a good cleaning.

Still another possibility is, unfortunately, that one of the arms on your Phantom got bent in the fall. It doesn't take much deviation in the arms to make the craft unstable in flight. Take a careful look around the part line of the shell and see if you can spot any bulging, cracks or separation... that's a good sign that the integrity of the shell has been compromised, and you should probably replace it.

 

[Creek.Jumper]

Thanks all. I took some time and had a really close look at it today. I re-did the IMU calibration and a compass calibration --- I did notice some things.

1. One of the props has a tiny 'nick' on the end of it. I dont think this would cause an issue but I will try new props for next flight.
2. The top of the phantom was on backwards! I noticed this because the "grooves" for the stickers were mismatched! I took this opportunity to remove the top and peek inside. It all looks to be in good condition. I took a high res picture incase someone else spots anything I missed. I blew out the inside and the motors with compressed air incase there was any debris. No visible damage, cracks, bulges or otherwise.
3. On the landing gear I notice what seems to be a "clip of some kind. Not sure why its there, or if something is missing from it. See below for pic

High res of open phantom: http://s28.photobucket.com/user/jmagaro ... d.jpg.html

Clip: http://i28.photobucket.com/albums/c225/ ... f01f94.jpg

 

[CityZen]

The P2 has a CAN bus connector attached to a landing gear leg (connects to 4-conductor cable). Not a vital part.
You can buy it separately if you ever need to attach anything to it.

Edit: I can see from your other picture that your CAN bus connector has been moved internally.

 

[ianwood]

One could argue that battery ejection is a good thing as it removes power and prevents possible electrically related damage.

And cuts the weight nearly in half when crashing on land.