I bet you can't make your Phantom do this... I am making progress...

[Marlin009]

I didn't move the compass, just recalibrated it. The bird was flying fine until I did the firmware update.

I was responding to the OP, not you.

Please define "moving the compass".

The compass isn't moved unless it's a few hundred miles from where it was initially calibrated. Technically, it is moved each time you're more than a few feet from where you last calibrated it. All of the known, correct, information out there shows that a new compass calibration isn't required in less than a hundred kilometers. Most say less than 300Km.

So please. Be specific.

I'll try. The OP said he moved his compass.

 

[IflyinWY]

I was using the Naza software and it notified me that firmware v4.02 was available. I did the update, recalibrated the IMU and compass and then I couldn't control the copter. I crashed three times in a row. There are storms in the area and I wonder if the electrical activity in the air was causing me problems. I hope it's not the update that caused it because I don't know how to take it back to the last revision of firmware.

Anyone have any thoughts on this. BTW, the wind hadn't been bad at that point. I gave up when the wind started picking up.

Robbie,
Please go here for discussions about the NAZA update.
http://www.phantompilots.com/threads/anyone-perform-the-new-naza-update.45338/#post-418607

This thread is about issues I am having with MY bird. No one is chatting with you about a compass here.
Thank you.

 

[IflyinWY]

Was it doing this before you moved the compass? You mention fixing a yaw issue. Did you move it back?

Sorry Marlin, I couldn't make sense of the thread for a while there.

Yes it was, and no I did not move it back. The yaw issue still exists.

My compass is mounted on the right rear leg, just like when new. I moved it down about 1/4 inch, 6 millimeters. It is now located almost exactly where the brand new compass, which just arrived today, is located on the leg it came mounted to. I guess when you buy a compass they send it to you on a landing gear leg.

The bird has been acting crazy, just like in the video, for weeks. I will mount the new compass, check it in the NAZA assistant, calibrate it and fly tomorrow. Perhaps that will resolve my yaw issues.

 

[IflyinWY]

Please define "moving the compass".

The compass isn't moved unless it's a few hundred miles from where it was initially calibrated. Technically, it is moved each time you're more than a few feet from where you last calibrated it. All of the known, correct, information out there shows that a new compass calibration isn't required in less than a hundred kilometers. Most say less than 300Km.

So please. Be specific.

No one is talking about what you are referring to. Sorry for the confusion, I was confused too.

 

[BlackHawk388]

No one is talking about what you are referring to. Sorry for the confusion, I was confused too.

Yeah, that didn't make a lot of sense in the context of this thread with the information provided prior to his comment. I'll chalk it up to his being tired like I was the other night.

I hope your new compass cures your problems! That would be highly irritating. Good luck!

 

[Clive]

Does it bounce up and down in ATTI mode as well as GPS mode? Does it do this at altitude (ie. Out of ground effect)? Thinking about this...

 

[IflyinWY]

Does it bounce up and down in ATTI mode as well as GPS mode? Does it do this at altitude (ie. Out of ground effect)? Thinking about this...

Thanks for your reply Clive.

No it doesn't do it at altitude, out of ground effect, I don't know about in ATTI mode, maybe I will try it today.
I believe the problem is a bit less than it was. Sometimes it flies very well, other times not so well.
Yesterday it flew very nice and I was able to video my new P1 flying.

I'm pretty stumped.

 

[Clive]

The autopilot uses GPS in GPS mode to aid altitude keeping, I think, and the height channel in GPS can be less accurate than in the XY plane, the autopilot in that plane may be a little less responsive so may 'get out of phase' if there is a changing GPS input... Your video looked like a classic pilot induced oscillation on a manned aircraft... Made me think. In ATTI modes, the quad uses barometric input... Which is heavily damped so should be different. I thought about ground effect too. Hovering in GE takes less power than in free air. If you have a heavy quad and slowish responding autopilot/ESC/ motors, bouncing in and out of GE could happen?

Btw I am not a quad expert... Just trying to remember many years back to helicopter aerodynamics and stability and control courses at university!

 

[Clive]

Oh... And high altitude/ hot climate (thin air) would exacerbate...

 

[IflyinWY]

The autopilot uses GPS in GPS mode to aid altitude keeping, I think, and the height channel in GPS can be less accurate than in the XY plane, the autopilot in that plane may be a little less responsive so may 'get out of phase' if there is a changing GPS input... Your video looked like a classic pilot induced oscillation on a manned aircraft... Made me think. In ATTI modes, the quad uses barometric input... Which is heavily damped so should be different. I thought about ground effect too. Hovering in GE takes less power than in free air. If you have a heavy quad and slowish responding autopilot/ESC/ motors, bouncing in and out of GE could happen?

Btw I am not a quad expert... Just trying to remember many years back to helicopter aerodynamics and stability and control courses at university!

Sounds like you know your stuff. I do fly a pretty heavy bird, 1120 to 1170 grams, depending on which battery I use.

The ground effect scenario sounds very likely, but a little different. I had my Vertical gain set at 125 or 150 at the time of the video. I would have thought the higher setting would result in a faster response, now I'm thinking it's just an "over response" I have since reset all gains to default.

My lanyard had some metal clips which I believe to be magnetic. They are now in the garage and will never be near my birds again.

Interesting point about the barometer being damped. Perhaps my battery door being removed and a couple 3/8" holes being drilled in the body have created an issue for me as well.

I also believe the "Foil mod" on the GPS isn't helping matters. The foil mod is where you remove the lid and coat the inside of the top with aluminum foil to get better GPS reception... didn't work for me.

I think I am gradually eliminating issues. Flying where there are a great deal of ferrous metals in/on the ground doesn't help much either. Many of the locations I fly from are gravel roads. I've started moving away from the roads and launching from a plastic storage tub which is 15" tall.

So, pilot induced?
Yep, I think much of my issue has been pilot induced, just not with the controls.

 

[Clive]

The gain thing is a definite possibility. In closed loop control systems, if the gain is wrong, sometimes oscillations can be induced by the system inputting a demand before the effect of the previous demand has taken full effect/been sensed. You get a faster response but too high and the system is over correcting all the time. Ground effect would exacerbate this as the power to remain level will vary with height above ground.

Trying ATTI would eliminate GPS as a contributor... I never thought much of the foil mod but also have never (yet) had an issue with GPS reception. I don't think your airframe mods will affect the baro sensor.

I operate at about 1170g max... Walkera plastic gimbal, GoPro, prop guards, sometimes the fc40 as well and I have a small altimeter... I am playing with a number of different props to find the optimum. I notice on the forum configurations that must be an awful lot heavier!

 

[Clive]

Any progress with your bouncing bird?

 

[IflyinWY]

Any progress with your bouncing bird?

I've been out of town and missed your reply till now.

Yes, some. Quite a bit actually. I've been undoing all the "Bad Dos" that I've done and each seems to be a contributor. The first link is video from the FC40, the second is video of the FC40. Let me know what you think.
Thanks Clive, your ideas have helped quite a bit.

http://www.phantompilots.com/thread...rams-without-antenna.44907/page-2#post-422021

http://www.phantompilots.com/thread...rams-without-antenna.44907/page-2#post-423211

 

[Clive]

Looks much better. Love the air to air shots!

 

[mad in nc]

I got sea sick watching the video - hope ya get it to stay still. what was the "overmod" fix