P4P Major Tilted Horizon (Even after IMU/Gimbal Calibration)

[skyeboysteve]

I reported a week ago about my extreme gimbal drift issues (and posted a video as well, see above), even after the latest fw upgrade.

Today, I'm happy to report that I think I found a fix (at least it worked for me). I would like to do some more testing before I emphatically say my issue is gone, but today when I flew, it was a million times better. Some of you may have heard of this method, but I went extreme and was super careful to get a perfect IMU and gimbal calibration. Here's what I did.

1. Went to Lowes and got a 18" x 18" pane of glass (probably could have been a little smaller too, but it worked). Also got a bubble level and a mini torpedo level.
2. Still have cold nights here, so set the drone outside for a few minutes to get it cold before IMU calibration.
3. With drone still off, I balanced my pane of glass on top of the 4 motors and set my bubble level on it.
4. Used playing cards under the landing gear to get a perfect center on the bubble level. Also checked with torpedo level for good measure.
5. Removed the glass pane without touching the drone, and placed it on the ground.
6. Again used my levelers to get the pane of glass perfectly level on the ground (if your house is like mine, it's nearly impossible to find any table or floor that is 100% perfectly level).
7. Turned on drone and immediately began IMU calibration. Kept drone in place thru step 1 of calibration.
8. Then I used my level pane of glass on the floor for steps 2 thru 6 of IMU calibration.
9. After that was done, I put the drone back on the floor and glass back on top of motors. Leveled it again using bubble leveler and playing cards.
10. Gimbal auto-calibration.
11. Flew again this morning, and my gimbal was remarkably better. It was level, and even more importantly than that, it did not tilt and sway as I yawed the bird.

I still want to fly a few more times before I say it's definitely fixed, but I was very happy with today's flight compared to last time I flew. I hope this info helps you guys with the same issue!

Has your improvement lasted since your first test?

Fortunately, I have a table that's pretty level, but the bubble isn't perfectly centered in one direction, so I tried the glass trick described above with a couple playing cards--making sure it was PERFECTLY level in several directions. It made no difference with my gimble tilt though after re-calibrating my IMU while the motors were all perfectly level with each other. In fact, it seemed to have gotten worse--especially when flying sideways into a wind--getting up to 5 degrees slant, which is the worst I've ever seen with any of the Phantom's I've owned. I was about to send it back to DJI with hopes I'd win the lottery with another gimble that would behave better... However, over the weekend, I came across someone's YouTube video on undocumented tips for the P4P. He mentioned that by holding down the C2 button (like you do to adjust the gimble roll with the dial) that it would "auto-level" itself! So last night I was going to have my wife twirl the P4P around (as gimble tilt always happened in a yaw)... but the gimble behaved perfectly. So, then I wondered if perhaps the gimble was affected by flight under power--so I flew it around the kitchen, and once again during yaw, the gimble stayed nice and level.

So this morning, I flew outside with a 15mph wind. To my surprise the gimble still worked perfectly while yawing (which has never happened before), and when I flew sideways into the wind, the gimble did tilt a little but less than 2 degrees--much more tolerable than the 5 degrees I was getting earlier. In any case, holding the C2 button down did NOTHING to "auto-level" the gimble.

Maybe I'll hold off on sending my P4P back to DJI--perhaps it decided to start behaving itself once under threat of getting shipped to California.

 

[RyanK]

Has your improvement lasted since your first test?

Fortunately, I have a table that's pretty level, but the bubble isn't perfectly centered in one direction, so I tried the glass trick described above with a couple playing cards--making sure it was PERFECTLY level in several directions. It made no difference with my gimble tilt though after re-calibrating my IMU while the motors were all perfectly level with each other. In fact, it seemed to have gotten worse--especially when flying sideways into a wind--getting up to 5 degrees slant, which is the worst I've ever seen with any of the Phantom's I've owned. I was about to send it back to DJI with hopes I'd win the lottery with another gimble that would behave better... However, over the weekend, I came across someone's YouTube video on undocumented tips for the P4P. He mentioned that by holding down the C2 button (like you do to adjust the gimble roll with the dial) that it would "auto-level" itself! So last night I was going to have my wife twirl the P4P around (as gimble tilt always happened in a yaw)... but the gimble behaved perfectly. So, then I wondered if perhaps the gimble was affected by flight under power--so I flew it around the kitchen, and once again during yaw, the gimble stayed nice and level.

So this morning, I flew outside with a 15mph wind. To my surprise the gimble still worked perfectly while yawing (which has never happened before), and when I flew sideways into the wind, the gimble did tilt a little but less than 2 degrees--much more tolerable than the 5 degrees I was getting earlier. In any case, holding the C2 button down did NOTHING to "auto-level" the gimble.

Maybe I'll hold off on sending my P4P back to DJI--perhaps it decided to start behaving itself once under threat of getting shipped to California.

I have flown quite a few times now since doing my IMU calibration and gimbal calibration trick mentioned above. I do still notice, on occasion, and sometimes worse than others, that the gimbal misbehaves (especially if I'm fast yawing). And I also find myself needing to adjust the gimbal before shots quite a bit, but it still has never been as bad as the video I posted about how it used to be. I have found it to be bearable, and still might have to send back to DJI at some point, but for now, I'm just dealing with it.

 

[Kristina Fowler]

For a Gimbal Calibration, how necessary is it to use a technically perfect level surface - to the extent of absolutely level bubbles. I'm using a granite counter top that "appears" to be level. How crucial is "Absolute Level"?

 

[RyanK]

For a Gimbal Calibration, how necessary is it to use a technically perfect level surface - to the extent of absolutely level bubbles. I'm using a granite counter top that "appears" to be level. How crucial is "Absolute Level"?

All I can say is that I've had much better results when I've gone to great lengths to make sure it's level.

The thing about a level surface like a granite countertop may not be enough. If the little foam pads on the bottom of the drone are not perfectly level themselves, then it won't matter that you are using a level surface. That's why I prefer the glass on top of the drone method because that way the drone itself is perfectly level on the first part of the calibration.

 

[skyeboysteve]

I personally haven't noticed any difference. I've gone through great lengths using two plates of glass that were shimmed so that they were perfectly level in all directions. Then shimmed the landing gear so that the plate of glass on top of the motors was perfectly level. Made no difference in the end from just using my kitchen table which slopes slightly to where the bubble is still between the lines but not perfectly centered in one direction. (The lower plate of glass was for IMU calibration on the P4P for when it came time to turn it on its side and upside down--but even this can have "errors" from any deformations in the body of the drone).

 

[blankester]

Great to hear you found a fix Ryan. Interested to hear your gimbal stayed straight after the first few flights i.e. was it a permanent fix?

Thanks

Barney

I reported a week ago about my extreme gimbal drift issues (and posted a video as well, see above), even after the latest fw upgrade.

Today, I'm happy to report that I think I found a fix (at least it worked for me). I would like to do some more testing before I emphatically say my issue is gone, but today when I flew, it was a million times better. Some of you may have heard of this method, but I went extreme and was super careful to get a perfect IMU and gimbal calibration. Here's what I did.

1. Went to Lowes and got a 18" x 18" pane of glass (probably could have been a little smaller too, but it worked). Also got a bubble level and a mini torpedo level.
2. Still have cold nights here, so set the drone outside for a few minutes to get it cold before IMU calibration.
3. With drone still off, I balanced my pane of glass on top of the 4 motors and set my bubble level on it.
4. Used playing cards under the landing gear to get a perfect center on the bubble level. Also checked with torpedo level for good measure.
5. Removed the glass pane without touching the drone, and placed it on the ground.
6. Again used my levelers to get the pane of glass perfectly level on the ground (if your house is like mine, it's nearly impossible to find any table or floor that is 100% perfectly level).
7. Turned on drone and immediately began IMU calibration. Kept drone in place thru step 1 of calibration.
8. Then I used my level pane of glass on the floor for steps 2 thru 6 of IMU calibration.
9. After that was done, I put the drone back on the floor and glass back on top of motors. Leveled it again using bubble leveler and playing cards.
10. Gimbal auto-calibration.
11. Flew again this morning, and my gimbal was remarkably better. It was level, and even more importantly than that, it did not tilt and sway as I yawed the bird.

I still want to fly a few more times before I say it's definitely fixed, but I was very happy with today's flight compared to last time I flew. I hope this info helps you guys with the same issue!

 

[RyanK]

Great to hear you found a fix Ryan. Interested to hear your gimbal stayed straight after the first few flights i.e. was it a permanent fix?

Thanks

Barney

Yes . . . well, for the most part. As for the video I posted earlier in this thread, YES, that is definitely fixed. I don't see it just swaying all around like that anymore. BUT, I do still have to routinely adjust the gimbal before starting to film or taking a photo to be sure the horizon is perfectly straight. My P3A was never that way, so it's still a pain, and it amazes me that it was so solid on the P3A, but not so much on the P4P. I do think doing a really proper IMU calibration does help though.

 

[Herbied143]

This gimble issue is freakin' ridiculous. I have a brand new P4P that I took out for the first time today. Ran 2 batteries worth of learning and fun. After putting in the 3rd battery the gimble went wonky. I flew it for a minute trying to correct the angle of horizon. Landed it, tried gimble and IMU recalibration to no avail.
I come home and get on here and see so many with similar gimble issues. Really makes me wonder how on earth did DJI get the market share they have. And no, I will not send my unit in so they can send back a refurb unit with the same issue (and maybe a few others). Add this to another issue I've already experienced with the battery that came with it not charging (but the spare batteries I bought with it are fine) and I'm not feeling warm and fuzzy with DJI and the Phantom series!

 

[Oso]

This gimble issue is freakin' ridiculous. I have a brand new P4P that I took out for the first time today. Ran 2 batteries worth of learning and fun. After putting in the 3rd battery the gimble went wonky. I flew it for a minute trying to correct the angle of horizon. Landed it, tried gimble and IMU recalibration to no avail.
I come home and get on here and see so many with similar gimble issues. Really makes me wonder how on earth did DJI get the market share they have. And no, I will not send my unit in so they can send back a refurb unit with the same issue (and maybe a few others). Add this to another issue I've already experienced with the battery that came with it not charging (but the spare batteries I bought with it are fine) and I'm not feeling warm and fuzzy with DJI and the Phantom series!

Yeah, the tilted horizon and the drifting horizon have been a signature issue with DJI drones for years. Of course, those who don't suffer from it normally just say to do a calibration of the gimbal or IMU as you've noted you've already done. Those who do suffer from it know that it doesn't help or only helps for a single flight and then right back to a tilted horizon. My first P3A suffered from the drifting horizon which could not be corrected so I just bought a new one and got lucky with the second one. That was back in 2015 and even these years later we routinely see people comment on horizon issues across all models. Of course when so many units are sold, some are bound to have issues and the issues are what we see here on the forum.