Yawing/Rotating While Descending. Vortex?
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quint7
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Hi:

I tried recallibrating the IMU and the RC as suggested in this other thread:  http://forum.dji.com/thread-58114-1-1.html

I pull straight down to descend and it immediatley starts spinning to the right.

It's so bad I really don't like going up over 200 feet now cause it takes so much concentration and time descending without feeling like I'm losing control. The faster I descend the faster it spins. Here is a new example I made with the camera pointing straight down today.

https://www.dropbox.com/s/a3el1a ... %20Example.mov?dl=0

It immediatly starts rotating to the right. You can see it spins pretty fast and pretty bad. This is from about 360 feet to 270 feet. The sticks show 100% down and 55% to the right, but there is no way I'm doing that much to the right. I'm basically pulling straight down. (Should I be concerned about seeing the footpad towards the end? Almost like a vortex?

I basically have to pull down and way to the left and really concentrate on watching the bird when descending. Takes the fun out of flying high cause it takes so much concentration and time to descend. Cause otherwise it's starts to spin really fast like this.

What else should I do?

Thanks,

Quint
2016-7-19
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Cetaman
Captain
Flight distance : 2528264 ft
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Aloha Quint,

     Good to read that you can bring her down in a controlled manner.  Have you calibrated the compass?  

     After you calibrate the Remote Controller, do you test the the yaw axis?  Does the test still show a 55% push to right?

     How are your Gains and Expos?  If nothing shows an obvious problem, you can go in and restore all the defaults to your settings options (after writing down your preferred settings first!)  Test your bird on descent again and see if the problem is still there.

     On the up side, it probably has nothing to do with Vortex Ring State.  VRS is random, your problem is predictable and with predictable direction.  DJI has also designed away most of the VRS problem so descent speeds can be faster (that is why your motors are angled like that).  Your problem needs to be solved, but angled approaches like a plane makes and spiral descents are also a lot of fun!

     Let me know how it goes.

Aloha and Drone On!
2016-7-19
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DJI-H.C
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Hi, it has nothing to do with Vortex.

Have you tried to use DJI Go to direct the drone to land automatically? See if it still rotates.  If it doesn't, it means that the culprit is with the RC.  It does look like something wrong with the pad under the control stick. Probably some fine particles stuck in it.  

Did this just happen one day, or after you update the firmware?   If this just suddenly happened, it might be something hardware, and you may need to contact support@dji.com to return it to DJI for repair. It takes less than two weeks, including shipping time.

2016-7-19
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DJI-Paladin
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Hello Quint, if it is convenient, could you please upload the flight records via DJI Go app and provide me with your DJI account here? Light up the star of the corresponding record before syncing will be recommended.
2016-7-19
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quint7
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Thanks. DJI-Paladin, I synced the flight records and starred that flight. 7/19/2016. The first flight in Vineyard. The time where I test is about 4 mins into the flight.

You'll notice in the next flight about 10 mins in a do a test drop from about 160 feet and I keep the bird straight. But even though it shows I'm pulling straight down, I'm really pulling down and a lot to the left as well to compensate for it pulling right. Even though it doesn't show it on the sticks. Thanks for looking at this.
2016-7-20
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quint7
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OK. I figured out what MY problem was. I had the sticks adjusted really really long so I would have more sensitivity and control when shooting video. I adjusted the sticks back down to the lowest and I had no problem. So what was happening is they had so much sensitivity just a tiny, tiny, tiny but of something to the right, it was spinning. Now with them back to shorter it totally operated fine.

So if I make the sticks long again, I'll have to go in and mess with the gain and expo in order to compensate.

So maybe that's another thing to ask people when they have this happen. How long are your sticks?

Thanks for all input.

Quint
2016-7-20
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DJI-H.C
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quint7 Posted at 2016-7-21 12:01
OK. I figured out what MY problem was. I had the sticks adjusted really really long so I would have  ...

Glad it's solved. I assume it wouldn't rotate if you use auto-landing or auto-take off through app?
2016-7-20
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Phantomski
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if u still see rotation, even on autoland, i'd replace ALL props.. see what happens.. props DO bend and change shape with time, just enough to change lift characteristics... probably does not happen often, but...
2016-7-20
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quint7
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DJI-H.C Posted at 2016-7-21 00:27
Glad it's solved. I assume it wouldn't rotate if you use auto-landing or auto-take off through app ...

I knew it was going to land or rise ok on auto all along. I knew it had SOMETHING to do with the RC in one way or another. Thanks again.
2016-7-21
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DJI-Ken
DJI team
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quint7 Posted at 2016-7-21 11:01
OK. I figured out what MY problem was. I had the sticks adjusted really really long so I would have  ...

That's correct, I have my EXPO lowered so the sticks are not so sensitive around the center and that will give you better control.
2016-7-21
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