Trying to figure out if this is a system limitation.  BACKGROUND:  I am not a Noob, I have flown several gimbal systems from full Sized Ronin's Ronin' M's Ronin XT's wide range of other Zenmuse Gimbals (GH4, A7 and the various Inspire's X3/5/5R/5S, Freefly MOVI's and Alexmos controlled DIY systems.  Not even my Alexmos "Fauvi" will do this once it is all dialed in. I can accept a little drift no more than a degree.  But once it starts banking to 5+ degrees, that seems a little exessive.  Yes I calibrated this gimbal several times on a perfect level surface.  Thats not the issue because it knows where level is.  After it drifts and I stop the aircraft it levels back on its own after coaxing it with a few yaw movements.  It seems like anything beyond 20 mph of airspeed it is having this issue.  It shouldn't  It should be fairly rock solid.  I also notice when I rack the roll stick back and forth abruptly banking the aircraft it lags you can start seeing it roll back and fourth.  This is indicative of  a P value Gain lag or that motor is not getting enough power, which is essentially the same thing,where it just cant quite react fast enough to the oposing forces.  No issues with pitch, I can go into the wind at full bore into the win and it does not do this, even with some pitch smoothness put in.

This is my second bird.  Bought one and even exchanged it.  The first one was out of tolorance for the gimbal balance, when off it would flop to one side, which is not supposed to do that.  The gimbal is supposed to be balanced perfect, meaning it should just stay where you put it.  I was hoping that was possibly the issue, but apperently not.  

TLDR:  Wondering if anyone actually has one that can maintain level at high speeds and does not do this, which means the retailer I got both could have a batch of defective models with roll motor QC issues.

My new P4Pro after cold IMU and gimbal calibrations on a flat, level surface has a level gimbal horizon only when hovering while facing into or directly away from the direction of wind. The gimbal tilts noticeably to the right when flying forward at speeds greater than 15 mph (regardless of wind direction), when flying sideways, or even while hovering if there is a cross wind coming from the right. Rotating the aircraft 360 degrees will often correct the gimbal tilt but horizon soon starts tilting again 10-20 seconds after completing the turn.

Horizon issues are becoming a nightmare for me. Imu and all the bla bla bla are calibrated as per dji videos and instructions.

I hope one day this gets fixed.

TheMann58 Posted at 2017-4-24 05:59
My new P4Pro after cold IMU and gimbal calibrations on a flat, level surface has a level gimbal horizon only when hovering while facing into or directly away from the direction of wind. The gimbal tilts noticeably to the right when flying forward at speeds greater than 15 mph (regardless of wind direction), when flying sideways, or even while hovering if there is a cross wind coming from the right. Rotating the aircraft 360 degrees will often correct the gimbal tilt but horizon soon starts tilting again 10-20 seconds after completing the turn.

That's exactly the behavior I see except mine will go head on into the wind without issue.  When its sideways it leans bad.  I can sort of coax it back to level by going into the manual roll adjustment and up it in the opposite direction by 4.5 degrees.  But then if I slide in the opposite direction the error is worse because now the manual adjustment causes the roll.  If I do no adjustment, I get the same response.  After I yaw a few times either 360 or a couple 90's it goes right back to center.  This is not a calibration issue IMO.  It has to be a control system issue like the motor is not at the right gain value.  There is no way to adjust this with the phantom.  They need to up the gain on that motor.  I don't understand why they don't.  I am seeing this as an issue from others since the P4P came out.

It's ironic they're introducing state of the art gimbals (Ronin 2) and at the same time they're doing nothing about this absolutely HORRIBLE bug in their 'prosumer' model.