New Phantom keeps flying away...

[tristanb]

Hi there,

I have a new phantom, I'm a heli pilot so not new to RC, but new to quads. I installed a CM2000 gimbal, and a FBOSD ghost, with a Predator FPV. I've tried the fly the phantom twice, I calibrate the compass, have the RC set to GPS and home lock, wait for the slow green lights, take off, and the phantom will act as if its in (from what I have understood, ATTI) mode, and fly with the wind, for say, 30 meters. I can control it, but it acts as if its under manual. It loves to zoom off. It seems quite unstable. It just seems to ignore the GPS.

Its balanced, has carbon props on it (also balanced), and shows no errors when I connect it too the software, I also tried upgradring to 4.0 - but no luck.

Any idea on how, or what it could be causing it to ignore GPS mode and fly like a kite?

 

[martcerv]

Are you flying in an open area or in a place with tall buildings or trees all around you? Gps needs direct los to at least 6 satellites and if it doesnt get these it reverts to atti mode. The more open sky you can see the more success you will have with the gps mode, if your flying in a dense area best to just fly atti mode so you will know what to expect. If it keeps going in and out of gps mode due to a poor location it will be quite hard to control as the 2 modes behave quite differently.

 

[Driffill]

I'd double check the FBOSD-ghost install. That wires onto the GPS puck, ensure that hasn't been damaged, then double check the other ghost connections. Having installed one myself, I can say they are a little tricky to get on the first shot!

 

[tristanb]

Well, last night I ended up going through the ghost, and all other wirimg no problems there and the NAza assistant shows no obvious error it gets GPS and compass readings. I'm flying in a field so location is not the problem.
Really feeling stuck with this one...

One thing i did find in the naza software was the IMU calibration pane under tools. it said it needed calibrating, so I did that. CHance that might have caused the Phantom to drift off and not use GPS?

Also in assistant, i checked the transmittor switches, and it is indeed in GPS ATTI mode not another one.

 

[jumanoc]

My suggest, do step by step discard:

1- Disconnect Ghost OSD and try GPS mode flight
2- Unmount Gimbal and try GPS mode flight

You'll find the guilty device :geek:

 

[tristanb]

No luck after tracing all the connections, and disabling the ghost / gymbal.

Is there any form of diagnostics I can run?

NAZA assistant shows GPS readings, sat fixes are ok, compass gives readings. I'm at a loss.

 

[TickTock]

It loves to zoom off. It seems quite unstable. It just seems to ignore the GPS.

ATTI is not unstable - just moves with any breeze. Should not zoom off. Is it possible you mounted the top backwards (do the sticker indentations on the top line up with the indentations on the bottom)? Is it possible the compass got moved to the wrong leg (or the leg with the compass got put in the opposite location)? The reason I ask is if your compass got rotated 180 degrees from the NAZA it will behave like you say.

 

[tristanb]

Your a genius ticktock!
I think I mounted the compass in the right leg (if LEDs are on back) and from checking photos I see the default is on the left.
Ill try this, thanks so much.

Out of interest is there a software solution to this or do I just need to remount.
Fingers crossed, but I think this might be it...

 

[tristanb]

So yes, I do indeed have the compass mounted on the opposite leg than where it was installed orginally. This is because my FPV wiring comes out the left side, so i moved it too the right.
Is there a way to adjust in software, or do I need to re-wire the FPV (bit or a mission as I will have to lengthen the cables).
Again, thanks so much for the tip, would simply not of thought of it!

 

[TickTock]

Glad I could help. I encountered the same problem: http://www.phantompilots.com/viewtopic.php?f=5&t=662

I just pulled up the 3.16 software and could find no place to adjust the compass orientation. If you really can't move it back, you could try rotating it around the leg it's on but I suspect it won't fit well unless you are willing to attack the leg with a file or Dremel.

 

[marcus_canada]

Good catch TickTock !