P2 flies away

The Phantom · Sep 1, 2014

My P2 is behaving very strange. It all of a sudden starts to fly away sideways in a very fast speed, the best thing i can do is to try to get it up as high as possible before it hits something. Its very hard to control the P2 sideways when this happens. It didn't happen before, it has been like this for about the five last flights.
I had a light crash earlier without any visible damage, I'm not sure if this started to happen directly after the crash or not?
It often happens almost directly after start. Sometimes it gets better after a while and sometimes not.
I have good GPS reception with about 11 satellites and the lights on the P2 is green.

Anyone have any ideas what it can be and a possible fix for this?

GerdS · Sep 1, 2014

When you increase throttle during takeoff, how do the motors sound? All similar or is there a hearable rpm difference already? MAybe one motor has been damaged during your crash.
If you will place your P2 on a table, hold it with your hand at the skids and then increase throttle to about takeoff power, is there high vibration at the skids feelable?
Have you tried an advanced IMU calibration?
Have you checked the compass value and done a new calibration outdoors?

Regards, Gerd

The Phantom · Sep 1, 2014

Thanks for your suggestions. I tested your suggestion and there is no vibration in the landing skids, and the motors sound as usual. I have not done any advanced calibrations, actually i haven't even done a compass calibration, guess i should have tried that first, but i thought the P2 will tell you when it needs a compass calibration by blinking the LED´s in a certain color scheme?

Is my kind of problem something that can happen when there are calibration issues?
I will have to try the advanced IMU calibration, is that part self explanatory? Will also check the compass value and do a compass cal.

HarryT · Sep 1, 2014

This is a classic symptom of a compass calibration problem. Do a calibration.

The Phantom · Sep 1, 2014

Thanks will do as soon as time permits.

RobertMfromLI · Sep 2, 2014

The Phantom said:
Thanks will do as soon as time permits.

Also, we are presuming that the position of the compass hasn't changed? If it has, then there's your problem. The orientation of the compass must match the stock orientation (how far up or down doesn't seem to matter, whether it is tilted up, down, left or right DEFINITELY matters though).

I had a nice crash because I re-positioned mine on some new landing gear that would only allow mounting at a slight angle.

The Phantom · Sep 2, 2014

The compass seems to be positioned as it should, but a hobby store employee who saw my P2 noted that i have installed the cover the wrong way, he said that that could be a reason for the fly aways? What do you think about that?

RobertMfromLI · Sep 2, 2014

The Phantom said:
The compass seems to be positioned as it should, but a hobby store employee who saw my P2 noted that i have installed the cover the wrong way, he said that that could be a reason for the fly aways? What do you think about that?

The top cover? or the compass cover? Compass U/D orientation is definitely important too - the top must be up top (cable end).

Here's what our crash looked like - which seems to be what you are describing of yours...

[youtube]https://www.youtube.com/watch?v=wzblF5hSnHQ[/youtube]

The Phantom · Sep 2, 2014

I mean the top cover with the GPS unit.

N017RW · Sep 2, 2014

The phantom GPS does not have a forward orientation like the NAZA or compass.

I can see you possibly confused by colored stripes indication of the front but the red LEDs would still be correct.

The Phantom · Sep 2, 2014

Okay then that has nothing to do with the problem then. Yes it is the colored stripes that are not aligned on the top cover with the lower cover, well actually i have no stripe stickers on the drone, maybe thats why i installed the cover the wrong way. Well then i hope that it is the compass thats needs a calibration. If something has broke that makes the P2 behave this way, what could be broken, flight controller? Are there other parts than the compass that can make the P2 behave like it does if they are broken? I will have to make a calibration tomorrow.