Gimbal Flips mid air

[eroca]

I feel you man, best thing I do is to avoid flying the right side against the wind.
Hope they can fix yours. I havent send mine yet. Praying for an update to fix it.
I fear its a design flaw.

I been waiting for an update for a while but I can continue waiting. Flying this way it is a total waist of time. Video is unusable or required a lot of correction in post and tons of keyframe to correct the "woo-able horizon" and spherical photography hard to have a descent result ...in the past a breeze with the P3P.

 

[RickT]

Here is my Gimbal flip problem going straight up with winds around 12 mph, I wish they recalled this junk..

 

[GadgetGuy]

Here is my Gimbal flip problem going straight up with winds around 12 mph, I wish they recalled this junk..

How about returning it, for one with a properly balanced gimbal?

 

[RickT]

How about returning it, for one with a properly balanced gimbal?

Yeah going to do that, I just have a ton of work and I thought I was making a good decision by buying the best

 

[GadgetGuy]

Yeah going to do that, I just have a ton of work and I thought I was making a good decision by buying the best

Where did you buy it from?

 

[bkushner]

I've had this on every Phantom I've owned it's like Tilted Horizon.

 

[GadgetGuy]

I've had this on every Phantom I've owned it's like Tilted Horizon.

It shouldn't be happening, unless you are flying "like a crazy monkey" in high winds, at high speed, and making sharp turns. It should certainly not be happening with Obstacle Avoidance turned on, limiting speed to 30mph max, which minimized it for me. It hasn't yet happened on my 5th P4P, with 20 flights on it. It has on six others, though! No doubt that the P4P gimbal is less tolerant than the P4 gimbal, and could perhaps be a bit more robust, to handle the slightly larger camera. RickT's flips were extreme, clearly ruining any continuous video.

 

[GadgetGuy]

Yeah going to do that, I just have a ton of work and I thought I was making a good decision by buying the best

It is the best, but it is still not without some issues, especially if you end up with a bad unit.

 

[Jim Roof]

I have not scoured every last word on this topic, but so far have not happened upon anyone mentioning wind resistance as being a factor. It look to me that is the culprit.

Now, that brings up the question... did any of the people posting these videos have anything on the camera that would increase its wind resistance?

 

[ReubenMru]

Hello Folks, I was actually going to create a new post, but I'm glad I checked first, cause this is exactly what happened to me - On my very first long flight with my P4P - had it for 10 days - and only did 360° shots with it... first real flight and this **** happens...

You can skip till 06:24 to see it happen - I've had both the P4 and the P3Pro before And never had such issues... I bought the Phantom 4 Pro because my P4 had some video feed issues, (that are restored when you move the gimbal with your hand - ) and DJI is not repairing it even though it has never crashed and still on warranty, DJI was telling me that I would have to pay for repairs because the drone was for the french market and the HK dept will not repair it unless I pay for it... and the NL dept that deals with the french market will not accept shipments from non french locations...

So I now have two DJI drones under warranty that have issues :/

And btw, no, I was flying the stock drone... no add on to it... and yes I think it was the wind... I also got the warnings about it being windy.... but it wasn't... it was slightly windy at take off but then the wind died - as you can see the trees do not move at all :/

 

[ReubenMru]

Ha. Happened on my first flight. I about S&$!

My mechanical mind told me it was aligned with the gimbal pan. Into a turn is when mine failed. So I turned pan off in the gimbal settings and it's never happened again.

I think it's a safety trigger built into the gimbal just gone wrong.


Sent from my iPhone using PhantomPilots

Thanks, gonna try that and fly again ...

 

[Jim Roof]

and yes I think it was the wind... I also got the warnings about it being windy.... but it wasn't... it was slightly windy at take off but then the wind died - as you can see the trees do not move at all :/

It may not have been windy to someone on the ground, or even at tree level, but that does not mean it was not windy 100-200 feet up. Also, when I said 'wind' I should have probably said 'air'. It looks to me that the gimbal is being blown off of its weakest axis of rotation and, in all of these cases, it looks like it is the roll axis. All of the examples here show significant lateral movement just prior to this taking place.

Think about what your P4P looks like in the air when it is moving hard right. The body of the craft is rolling right, while the gimbal is reacting to maintain level. This will create a narrow gap between the upper right of the gimbal (as viewed from behind) and lower part of the body of the P4. The P4 is moving hard right, say 20-25 mph in P mode, and as that gap gets narrower and narrower as speed increased, the body creates an area of high pressure that is directed right at the gimbal and the only way for this pressure to be relieved is for the gimbal to rotate to the right to open up the gap between itself and the lower part of the body of the P4.

I think this is a function of aerodynamics and the gimbal is simply being overcome by the narrowed stream of air pressure. It will not happen going forward because the body pitches down, creating a LARGER open and no funneling of air pressure or velocity. And, I bet it would never happen when in FPV mode as the gimbal would never roll to the point that it is that close to the body.

 

[ReubenMru]

I'm not sure it's due to a narrow stream of air pressure, cause that would cause the camera to be drawn to the body of the aircraft... much like two cars going fast next to each other are pulled to each other...

What I think is happening, is that the bigger camera on the P4P is too heavy to be maintained in position by the gimbal motors against some wind - plus being bigger in size, it offers greater surface area for the force of the wind to act upon... and then the motors yield momentarily and the camera drops...

Btw, I got the "too windy" message while I was still below the tree line... and it was not windy... so that's why I don't understand why I'm seeing the propellers in the video feed... because there wasn't that much wind to go against....

 

[Jim Roof]

What I think is happening, is that the bigger camera on the P4P is too heavy to be maintained in position by the gimbal motors against some wind - plus being bigger in size, it offers greater surface area for the force of the wind to act upon... and then the motors yield momentarily and the camera drops...

I think you are right on the latter observation about the size of the camera, but not right about the wind flow issue. There cannot be any 'negative pressure' that would want to draw the two objects closer (your car analogy) without there also being a POSITIVE pressure that will also have an action. In the case of the cars, the negative pressure is a result of the frontal pressure upon the grill and front surfaces. Like an airfoil, that positive pressure has a balancing negative region. But in the case of the P4 and camera, it would be the camera getting hit with the more positive pressure airflow and conceivably, there could be a resulting area of low pressure that the camera and gimbal move INTO. And the weight of it would actually serve as a stabilizing influence since the gimbal wants to keep the camera hanging straight down as opposed to rolling to the right.

It would take a wind tunnel test to really pin this down, but air speed seems to be a factor. I still think the body starts to act like a baffle that concentrates pressure on the camera body. Flying at moderate speeds laterally, combined with some actual wind or wind gusts, likely overcome the mechanics of the gimbal and the motors that stabilize it.

 

[GadgetGuy]

The so called "gimbal flip" is actually the gimbal hitting a gimbal stop, and the camera then flips because it is no longer being leveled by the gimbal, until the gimbal moves away from the stop. You can simulate the camera flip by tilting the aircraft to extremes by hand on the ground, with the power on and the motors off. The camera will stay level until the gimbal hits a stop and then the camera flips. This hitting of the gimbal stop takes place in flight when the aircraft is tipping into the wind to avoid being blown off course, and is exacerbated by high winds, turns (left turns on my aircraft) and high speed which all increase the needed gimbal correction to keep the camera level. Eventually, the gimbal reaches the end of its range of correction, and hits a stop. Some of the P4P gimbals are more sensitive to this than others. Some have tried adding weight to the side of the camera opposite the flip to rebalance it. Flying slower and avoiding turns into the wind helps. I prefer to find an aircraft that is better balanced to start. The P4P gimbal isn't quite as robust as the P4 gimbal. Adding external batteries also helps, as the extra weight holds better against the wind, reducing the tilt needed.

 

[ReubenMru]

I was considering using some lose tape to allow motion in both sides but restrict the camera from falling down past the acceptable degree... but can't test it - or the pan option somebody mentioned above... it's been raining straight for 3 days over here... even schools are staying closed today :/

 

[GadgetGuy]

Even my best of seven P4P's had its first "gimbal flip" tonight when I switched into Sport mode and was chasing a train! One mild overhead turn at 40mph was all it took, even in calm no wind conditions. These gimbals are sensitive!

 

[ReubenMru]

That's annoying, I wasn't even in sports mode... wasn't going very fast either... gotta look at the tablet to find out... So how do we get DJI to comment and respond to this?

Thanks,

Reuben...

 

[GadgetGuy]

That's annoying, I wasn't even in sports mode... wasn't going very fast either... gotta look at the tablet to find out... So how do we get DJI to comment and respond to this?

Thanks,

Reuben...

Be careful what you ask for. I am told that the Inspire 1 had a similar issue that was "fixed" by a firmware update that crippled the aircraft top speed to "solve" the problem. The point of Sport mode at 40mph in calm winds is that you can generate the same aircraft tilt angle flying sideways at 30 mph with a 10mph wind, and then any gust or turn will cause the gimbal stop to be hit, and the camera flips in response.