Flying straight but body rotated CW

[Peterfz30]

Have a problem with Phantom 2 flying straight but with the body rotated about 30 degrees clockwise. See attachment.
I have calibrated IMU and only thing I can see is that the Compass (Raw) Z is 750.

Flies the Ground Station path perfectly finding the waypoints without any problems.

Anyone able to help please. :?:



Phantom 2 with GoPro and 2D mount and Ground Station

 

[ianwood]

Where are you located? Someone else here had a similar problem. They flew straight but the orientation was always off by the same amount.

 

[EMCSQUAR]

Go into assistant software and calibrate your sticks. (assistant software ->basic->RC )

 

[Peterfz30]

Hi Ian, I am located in Hobart Tasmania, the bottom part of East Australia. See attachment. Ian I also get the hockystick flying that you have written on extensively elsewhere. It would be hard to recommend the Phantom 2 if this problem cannot be resolved.



Thank you EMCSQUAR, I have calibrated the jotsticks which hasn't affected the problem.

 

[Mandrake]

Peterfz30... Control lock ???

Sent from the thing that does everything.

 

[ianwood]

I think you and adanac have the same issue: viewtopic.php?f=19&t=15173

Looks like this, right:

[youtube]http://www.youtube.com/watch?v=1BZdkXLaSOk[/youtube]

 

[Killobite]

I have the same issue. I really noticed it after I got my FPV up and running and the iOSD Mini, when I look at the home diamond through the FPV it is usually about 15 degrees west (to the right if I am heading South). The thing is if I put the center of the display over the diamond ( basically not looking at home really, but off to my left by quite a bit) and just full throttle the thing while keeping the diamond centered I fly straight to the home location, just not pointing at it. I have tested home lock and course lock, done numerous EMU calibrations both long and quick but nothing seems to change the off kilter heading.

The last time I opened it up I even looked around for anything that might be askew like the Gyro or something but did not see anything.

I just have to compensate while flying, not all that big a deal but it would be nice to be able to fly straight.

 

[Peterfz30]

Yes the same as adanac but on the opposite or left side.

Any ideas why this may be happening?

And to Mandrake, I am unsure what you mean about Control Lock.

 

[ianwood]

I have no idea but it appears a few people have the same issue. It might be declination related but not all of us experience it so there's something else uniquely common between the group of you.

 

[Killobite]

So, I managed to get a pretty good example out of my FPV DVR from a flight over the weekend. The first image is a couple minutes into the flight, the second is about 6 minutes later in the same flight. Actual home location is the little blue marker I drew on there.

As you can see the first one shows home quite a ways west of where it really is, but the second one is almost dead on. The thing is, even early on in the flight I could point the copter at "home" and it would fly straight to me, it was just crabbing a bit west initially...

 

[DesertFlyer53]

Have a problem with Phantom 2 flying straight but with the body rotated about 30 degrees clockwise. See attachment.
I have calibrated IMU and only thing I can see is that the Compass (Raw) Z is 750.

Flies the Ground Station path perfectly finding the waypoints without any problems.

Anyone able to help please. :?:



Phantom 2 with GoPro and 2D mount and Ground Station

I had a similar problem this past weekend. Are you using the stock DJI transmitter or a Futaba transmitter with ianwoods v4 profile? On my Futaba T8FGS, the left knob on the upper front face of the radio (sorry, don't have the radio in front of me so can't be more specific) is set to trim the rudder axis. It's used for slow panning in flight and works smoother than using the left rudder stick. When I powered up my Phantom and took off into a hover, it was yawing slowly to the left. That's when I noticed the knob was not centered. I trimmed the knob to stop the left yaw but had to be position it off center to get the Phantom to stop rotating. I thought that was odd be continued on with my flight. Something seemed off during the flight but I couldn't pinpoint what until I flew close enough to observe the Phantom in forward flight. That's when I noticed it was flying slightly sideways. I landed, shut down everything and swapped batteries for the next flight. While the radio was powered off, I centered the yaw knob then powered the radio on, followed by the Phantom. When I took off the second time, everything was back to normal and the Phantom flew straight as an arrow. What I think happened is this... one the first flight when I powered up the radio and Phantom, the yaw knob was not centered. As the Phantom was going through it's start up calibration, it tried to compensate for the off center yaw trim. That somehow screwed up the balanced flight calibration. I think it's the same thing as powering up when the sticks are not centered... it throws everything off. If you are still using the stock DJI transmitter, I would bet that your sticks are not calibrated properly. That's all I can figure since my second flight was perfect after I discovered the off center yaw trim.

 

[DesertFlyer53]

Go into assistant software and calibrate your sticks. (assistant software ->basic->RC )

+1

 

[DesertFlyer53]

Just watched the video posted here. Yup, my guess would be that the yaw stick calibration is off. Re-calibrate your sticks in the assistant if you're using the stock DJI controller. If your using a Futaba radio (or and other non DJI radio for that matter), make sure your trims are centered.

 

[Killobite]

Just watched the video posted here. Yup, my guess would be that the yaw stick calibration is off. Re-calibrate your sticks in the assistant if you're using the stock DJI controller. If your using a Futaba radio (or and other non DJI radio for that matter), make sure your trims are centered.

Thanks for the response but in my case at least, I have re-calibrated several times with no change. Also, over the course of the flight it straightens itself out. Before this particular flight I even took a plastic torpedo level and made sure my takeoff platform was level and the phantom was level in both axis as I did a compass calibration.

 

[ianwood]

So, I managed to get a pretty good example out of my FPV DVR from a flight over the weekend. The first image is a couple minutes into the flight, the second is about 6 minutes later in the same flight. Actual home location is the little blue marker I drew on there.

As you can see the first one shows home quite a ways west of where it really is, but the second one is almost dead on. The thing is, even early on in the flight I could point the copter at "home" and it would fly straight to me, it was just crabbing a bit west initially...

That looks to be part of the compass declination defect. The fact that it cleans up slowly over a period of several minutes is completely consistent.

 

[EMCSQUAR]

Something else you might check - open her up and have a look at solder connections from main board to ESCs and motors. Especially on opposite side from "yaw pull".
I had a similar situation a couple of months ago with one of my Phantoms, started off at weird direction until it warmed up. I went through multiple calibrations, checked multiple times - then it finally came down luckily in a snowbank - come to find out cold solder joint let go. The conclusion was connection was weak and made partial contact until warmed up whereas connection expanded & made better contact.

Just something else to check...

 

[Jotfree]

Have a problem with Phantom 2 flying straight but with the body rotated about 30 degrees clockwise. See attachment.
I have calibrated IMU and only thing I can see is that the Compass (Raw) Z is 750.

Flies the Ground Station path perfectly finding the waypoints without any problems.

Anyone able to help please. :?:



Phantom 2 with GoPro and 2D mount and Ground Station

I am experiencing the same issue as you to a tee. Fly straight with ground station... just very odd. I have calibrated and recenter the remote sticks and still the same. Seem to me this is a slight different issue then the j hooking issue that others are having. It more annoying than anything.