A little update, and more involved testing when it dries up (rained all day, finally stopped 4 hours ago)... I wanted to pay really close attention to my phantom 3's. I only took my 4k out to test this evening, and initially to break in a new battery is got today. Anyway, I decided to fly exactly as it did with my P4, and guess what? It did the same 2 - 5 foot yo-yo after flying a forward path.... maybe it is firmware related? I will test my advanced this weekend along with extensively testing the P4 and 4k.
Spontaneous 40' ascend with no input
- Thread starter John Locke
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I would agree with this, which supports the vortex suction theory playing havoc with the barometer only in a hover. When the craft is moving horizontally, the downward draft cannot create the perfect vortex to suck at the bottom vents. Now I'm really curious if putting tape over the vents as a test will have any effect on this anomaly.
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I should be testing that today provided the rain holds off, and it may be the perfect day to do so, as it's overcast and cooler, so covered vents won't have a serious negative impact on circulation / heat.
A lot depends on where the static port(s) are located. I would not have expected them to be located inside the body of the aircraft, since that would likely lead to venturi effects lowering the measured pressure. I can't see any obvious external ports, but with all the vents etc. on the lower surface it's hard to know.
N017RW
Premium Pilot
P4 is a completely different animal, multiple boards, etc. Maybe someone here that repairs Phantoms can locate the barometer in a P4 and let us know. Curious minds want to know.While this is a P4 discussion, on the P3s the baro is located on the bottom side of the main PCB (opposite the MC).
It is the rectangular device, silver in color, with two holes in opposite corners, located in the top left quadrant of the center section shown here:
N017RW
Premium Pilot
Maybe so but doubt there's anything significantly different other than possibly 2 baros. Dual compass and IMU but does that include a Baro?
So, I got this back from DJI about my Phatom 4 "yo yo" issue, which again is NOT as bad as most, but it seems they are aware, and, well, see for yourself.
"
Dear Tom,
Thank you for contacting DJI Customer Support. We are very sorry about the problem you are experiencing right now, especially with regards to the "Yo Yo" effect that affects the performance of your Phantom 4. We would like to advise you to avoid using a gimbal guard on the aircraft that has VPS, if you use a gimbal guard the sonar waves are bouncing off of it and going to make the aircraft do all kinds of altitude adjustments like in the video on the previous threads.
We will also update you right away with regards to the date for the next firmware update of Phantom 4.
Thank you for your cooperation. Let us know if you need further assistance and update with regards to this matter. Thank you and have a good day.
Regards,
DJI Customer Support"
The other stuff was just usual BS about things I never even mentioned I used, i.e. the Gimbal guard.. never once did I mention to them that I use one, as well as I do NOT use one for ANY UAV I own. But apparently they are aware, and are addressing it in the next firmware?
"
Dear Tom,
Thank you for contacting DJI Customer Support. We are very sorry about the problem you are experiencing right now, especially with regards to the "Yo Yo" effect that affects the performance of your Phantom 4. We would like to advise you to avoid using a gimbal guard on the aircraft that has VPS, if you use a gimbal guard the sonar waves are bouncing off of it and going to make the aircraft do all kinds of altitude adjustments like in the video on the previous threads.
We will also update you right away with regards to the date for the next firmware update of Phantom 4.
Thank you for your cooperation. Let us know if you need further assistance and update with regards to this matter. Thank you and have a good day.
Regards,
DJI Customer Support"
The other stuff was just usual BS about things I never even mentioned I used, i.e. the Gimbal guard.. never once did I mention to them that I use one, as well as I do NOT use one for ANY UAV I own. But apparently they are aware, and are addressing it in the next firmware?
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New firmware Phatom 4 v 1.1.410
I am going to sit back and let a week or two go by before I apply it. My P4 seems to work properly so updating would be more of a risk.
I am going to sit back and let a week or two go by before I apply it. My P4 seems to work properly so updating would be more of a risk.
are you referencing the go app? we're talking about firmware.
Who is brave enough? i might go ahead and do it as I don't have any photos or video shoots planned in the next couple weeks... I don't know though. I just had a "fight" with DJI support who said they don't support mine or any of your guys' claims, which i assume is a language barrier issue... I sent them here, and videos of the issues.. Hopefully this is now fixed, but man I am not wanting to pull that trigger.
It's apparent a gimbal guard will cause the 40-60' up and down yoyo effect, and new firmware will hopefully fix the 6-8' yoyo effect that almost everyone experiences with no gimbal guard, when suddenly stopping into a hover above 30'AGL. I think DJI is aware of both types of yoyo symptoms, which is a good thing.
So I just picked up my P4 from UPS and guess what..... they didn't repair it. They replaced the drone, it's got different serial number. I got a pristine new drone, stickers installed on top, not a scratch on the shell, no smudges on the camera glass, no marks on the rubber feet. I went all over this craft with a magnifying glass, it doesn't appear to be a rebuild,its flawless. So first impression is good. Tomorrow I'll take it out and give her a spin and see how she does. Tonight I'll do the IMU cal just to be safe and ground test camera, motors, gimbal, etc.
I originally sent it in with 3 complaints:
1. 40-60' yoyo effect (which I now know was caused by the gimbal guard I had installed). I explained it start out with a 6-8' yoyo effect since I bought it, than it grew to 40-60', and I provided DAT files to prove it. However, they told me to remove all accessories, including battery before I ship it to them.
2. 15mph top speed with OA enabled, it should do 22.
3. Poor signal integrity, losing control signal first spontaneously at 3000-4000ft distances (I've actually fixed that issue by using an Inspire controller), explaining to DJI my P3P goes 2miles under the same conditions and location where I fly all the time, and the P3P always loses video signal first.
Unfortunately they sent me the same RC back, same serial number. So I don't think they did anything to the RC to fix the control signal complaint. The strange thing is for the work done to the craft the paperwork stated "Phantom main control component - $96" with a discount of 100% since it's under warranty. But they sent me a whole new craft. Go figure.
I'll test the RC to see how it does, then revert to the Inspire RC again to compare.
I recently bought an Immersion RF meter just for grins. I plan to measure all the RF output levels between my 4 controllers and 3 birds. We'll see how they all compare.
So I just picked up my P4 from UPS and guess what..... they didn't repair it. They replaced the drone, it's got different serial number. I got a pristine new drone, stickers installed on top, not a scratch on the shell, no smudges on the camera glass, no marks on the rubber feet. I went all over this craft with a magnifying glass, it doesn't appear to be a rebuild,its flawless. So first impression is good. Tomorrow I'll take it out and give her a spin and see how she does. Tonight I'll do the IMU cal just to be safe and ground test camera, motors, gimbal, etc.
I originally sent it in with 3 complaints:
1. 40-60' yoyo effect (which I now know was caused by the gimbal guard I had installed). I explained it start out with a 6-8' yoyo effect since I bought it, than it grew to 40-60', and I provided DAT files to prove it. However, they told me to remove all accessories, including battery before I ship it to them.
2. 15mph top speed with OA enabled, it should do 22.
3. Poor signal integrity, losing control signal first spontaneously at 3000-4000ft distances (I've actually fixed that issue by using an Inspire controller), explaining to DJI my P3P goes 2miles under the same conditions and location where I fly all the time, and the P3P always loses video signal first.
Unfortunately they sent me the same RC back, same serial number. So I don't think they did anything to the RC to fix the control signal complaint. The strange thing is for the work done to the craft the paperwork stated "Phantom main control component - $96" with a discount of 100% since it's under warranty. But they sent me a whole new craft. Go figure.
I'll test the RC to see how it does, then revert to the Inspire RC again to compare.
I recently bought an Immersion RF meter just for grins. I plan to measure all the RF output levels between my 4 controllers and 3 birds. We'll see how they all compare.
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@John Locke
Congrats!
Could you please elaborate? What is the gimbal guard and why do you think it is causing this yoyo issue?
Congrats!
Could you please elaborate? What is the gimbal guard and why do you think it is causing this yoyo issue?
In this thread there's a video by BengalBoy showing a gimbal guard causes the large yoyo effect, NOT the 6-8' yoyos. Remove the guard and no more large yoyos. A gimbal guard is a generally a piece of carbon fiber material that attaches between both landing leg horizontals to provide the camera and gimbal a little protection when landing on uneven surfaces, such as a forced landing you're not in control of. Theoretically a gimbal guard, if designed right, doesn't obstruct the view of the down-facing VPS sensors, sonar and camera. These guards worked great on P3 craft, and they really saved my P3P camera in a crash I had last January. However with P4 the VPS technology is apparently much different, and the same sensor clearances for mounting don't work, given the evidence.
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@John Locke
Got it. TY. I am not using one.
I always thought that the Phantom could use some sort of better design to prevent it from tipping over in strong winds when the engines are on.
Thank you for the clarification/ info.
Got it. TY. I am not using one.
I always thought that the Phantom could use some sort of better design to prevent it from tipping over in strong winds when the engines are on.
Thank you for the clarification/ info.
It's called "Hand Catch". Never had an issue on takeoff in wind --just punch the throttle, don't baby it. Indoors takes a lighter touch. You gain that with an X5C or the like.
On rare occasions if you have just enough wind in the right direction, the P4 fires up the motors so fast (much higher speed than P3p which doesn't have this problem) that it will almost tip over the craft, there's nothing you can do about it. I'm sure with enough wind it could tip over unintentionally. The firmware needs tweaked to slow down the spin up. There's no need for the motors to spin up that fast since props aren't self tightening anymore like the P3P, which was the original belief why the motors rev up and down a couple times, to tighten props (I have a hard time believing that, but whatever).
I did obstruct the vents, I didn't try for very long, as it was seriously hot out and I am not sure how much they truly vent the machine, but there was no change when covering the vents unfortunately.
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