I have a second hand Phantom 3 Advanced that exhibits jello quite often. Most of the time, it is nice and smooth. However, sometimes it beins vibrating and displaying this effect.
This the return trip from a flight towards Mt Wilson in Red Rock Canyon. This was heading east traveling at about 20MPH, wind 8-10MPH, NNE. I have flown in much stonger wind and traveling much faster witout any jello effect

I have replaced the top shell, balanced propellers, replaced all 4 dampers and anti-drop pins. There are no cracks on the bottom shell. There is  no play anywhere on the gimbal. The gimbal does not make any strange noises.

How many anti-drop pins do you have installed?

Two, diagonally, of course.
Funny thing is, I made almost the same flight, just a little farther south, and the recording was perfect.

Offroader Posted at 2018-9-2 19:51
Two, diagonally, of course.
Funny thing is, I made almost the same flight, just a little farther south, and the recording was perfect.

The effect is almost rhythmic, as if something is vibrating in resonance. I can't think of anytihng to suggest.

This video is showing an unusual light leak in the form of a lateral streak or line across the picture.  It's not the normal radial lens flare towards the center that is to be expected when flying into the sun.  Is it possible you have a number of addons bolted to the camera?  Lens filters + shade hood for example?  I'm wondering if they aren't fitted securely, allowing light through and wobbling at times.  A heavy "payload" on the front of the camera could conceivably start a resonating wobble under certain conditions.

endotherm, I saw that too and is the first I have seen this artifact. I would have expected typical lens flair as I have on other videos taken at dusk. I had an ND4 filter and nothing else on the aircraft (other than a small strip of Velcro behind the downward position sensor housing for a Cree strobe). This filter is about 1.5 grains lighter than the clear lens cover supplied by DJI. The sun was at about the 1 o'clock position and perhaps 50 degrees high when traveling directly back to the car. It was more into the sun at the beginning of the video.

Geebax, it is almost rhythmic and I have seen this before. This is what led me to balance the props. Other videos would have the jello show for about 5 seconds then go away. Yaw, accelerate, brake or change altitude would generate another 5-7 second burst of jello. Almost as if a set of unbalanced props synchronized to start vibrating.

Offroader Posted at 2018-9-3 07:12
endotherm, I saw that too and is the first I have seen this artifact. I would have expected typical lens flair as I have on other videos taken at dusk. I had an ND4 filter and nothing else on the aircraft (other than a small strip of Velcro behind the downward position sensor housing for a Cree strobe). This filter is about 1.5 grains lighter than the clear lens cover supplied by DJI. The sun was at about the 1 o'clock position and perhaps 50 degrees high when traveling directly back to the car. It was more into the sun at the beginning of the video.

Geebax, it is almost rhythmic and I have seen this before. This is what led me to balance the props. Other videos would have the jello show for about 5 seconds then go away. Yaw, accelerate, brake or change altitude would generate another 5-7 second burst of jello. Almost as if a set of unbalanced props synchronized to start vibrating.

Can you set it up on a table and power it up and take a video of the camera and gimbal?  We are looking to see if there is any twitching while the aircraft is stable and at rest. Then perhaps introduce some slight movements to the body to see if the gimbal corrections are responding appropriately.

I have a P3A also. I have experienced that at times too. I might suggest try turning your Phantom or slow your speed down to see if it goes away. Mine takes really good video almost 100% of the time, but on occasion I will get the jello-effect too. I notice it when I and maybe trying to get a shot while moving sideways and have some wind and moving pretty fast. All my dampers are good, but it seems I get a bit of vibration or something. My props are balanced as you say yours are too. When I slow down or turn the aircraft a bit it will go away. Don't have a perfect answer for you here.

endotherm Posted at 2018-9-4 06:09
Can you set it up on a table and power it up and take a video of the camera and gimbal?  We are looking to see if there is any twitching while the aircraft is stable and at rest. Then perhaps introduce some slight movements to the body to see if the gimbal corrections are responding appropriately.

I can do that.  I have had it in the wind (20-25MPH)  and it struggles to hover and you can see the camera moving around trying to stay stable and there is no jello on the video.

I thought of attaching a straw to the screw hub but I can't find one with the correct diameter. The hope is to try to determine if any of the motors are not revolving on their axis correctly. Spinning the motors up without any props didn't reveal any wobbling.

RicardoGray Posted at 2018-9-4 09:21
I have a P3A also. I have experienced that at times too. I might suggest try turning your Phantom or slow your speed down to see if it goes away. Mine takes really good video almost 100% of the time, but on occasion I will get the jello-effect too. I notice it when I and maybe trying to get a shot while moving sideways and have some wind and moving pretty fast. All my dampers are good, but it seems I get a bit of vibration or something. My props are balanced as you say yours are too. When I slow down or turn the aircraft a bit it will go away. Don't have a perfect answer for you here.

This flight was the first time I have actually seen the effect on my tablet. I wasn't sure if it was jello or the stuttering/pixelating of the 720p downlink video. Reviewing the video positively showed the jello.

Variation of speed or direction seems to make is show up. Just like you, 95+% of the time everything is good. Just knowing it can show up is infuriating.

Offroader Posted at 2018-9-4 20:06
This flight was the first time I have actually seen the effect on my tablet. I wasn't sure if it was jello or the stuttering/pixelating of the 720p downlink video. Reviewing the video positively showed the jello.

Variation of speed or direction seems to make is show up. Just like you, 95+% of the time everything is good. Just knowing it can show up is infuriating.

Only thing I could suggest is to maybe re-calibrate the gimbal and reset the camera to the defaults, unless you already have been though all of that.
There was a time my phantom was acting kind of goofy, and I could change the exposure settings, and it wouldn't stay where I set it for some reason. Just acting weird, so I reset the camera to the defaults and then changed to the settings I wanted and everything straightened out perfectly. It wasn't having the jello problem you are experiencing, but thought I'd mention it
I use the ND filters too all of the time, and I don't think they are your problem. I know I did try using a filter and one of those sun shades one time, and my P3A just couldn't handle it with a little bit of wind. Caused the gimbal to just go crazy trying to keep things smooth. So, I have never used the sun shade any more. Maybe it was just my phantom, because I have heard of others using them. But you didn't have one of those on anyway. The ND filter should be fine. Kind of frustrating I know. Especially when you want to get something really cool only to find out what you have is unusable. But like we both agree it doesn't happen very much. Actually I haven't had that for a long time now, so I hope I am not inviting trouble! LOL Good luck to you and if you figure it out, let us know.

This is really bizarre. I've had about 12 flights on it since and could only find about 7 seconds of jello, all at once, on one video.  A few were in 15-20MPH wind and some were perfectly calm. As I said before, infuriating.