[Brunosanta]

Hello All, I have built a 250 quad for awhile, emax plastic motors 1805..., 5030 gemfan, simonk esc, 3 cells 4000 mili amps, and I experience many problems, PID's seems ok, at least P, cause I don't get that much shaking or vibration. I will list my problems:

calibration issue: I tried the calibration many times, board is in the correct orientation, if I see it correct on the flight data tab I try to fly in altitude, the motors spin and the quad flips over.. ( the board seems to be updside down although the image shows it correctly placed) basically I achieved a taking off by, letting the image all inverted in the flight data tab, then it will fly fine. making explanation easy: Roll right, results left in the image but drone rolls right.  pitch is also inverted in the image. I tried to rerun calibration if I do I get the flipping over thing. it only works if I dont calibrate and accept the image on the flight data tab inverted and fly it.

Cruise control, I tried the cruise control with two banks, one with TPS activated and with the P gains bigger, and one with the TPS dissabled and PIDS lower, for both, after doing a pitch forward and stopping I loose lots of altitude, if I yaw I gain altitude (lots) as long as I let go the stick ( axis lock activated). question: would the altitude loss be related to a throthle curve I created? what is the cruise control basing it at? why the yaw gains too much and roll and pitch it falls from the sky, after letting go the sticks?.. another small annoying error, the slightest wind will move my quad away slowly.

I tried the Altitude vario with my smoothest set of PID bank, fact is, my quad looks like a rabit, first I couldn't really find the hover point on the stick, second, if I give it throttle up or down, it starts oscillating badly vertically up and down. 
I m just begging for help here cause I am trying to calibrate it already for 3 weeks, and not getting any better, it feels like a headless quad a, and I would like to use at least the vario to teach my brother how to fly as well as making some footage without worrying so much about the quad. thank you guys in advance.

[TheOtherCliff]

First, you must have the board right side up and board arrow point forward.  If not, you must change "rotate virtual" in GCS -> Attitude -> Settings before running the vehicle wizard?

Flip over is usually caused by wrong prop direction / wrong prop (left hand vs. right hand), or wrong motor numbering sequence.  You cannot fix motor spinning the wrong way by putting the other kind of prop on.  Etc.  It must be perfectly exactly as shown in GCS->Configuration->Vehicle

You really need fast ESC's and you need to use fast ESC update options such as PwmSync, OneShot125, or PWM-490.

[TheOtherCliff]

Start with Attitude mode no GPS Assist, Manual thrust, and get that working well before adding more things.

Once that is working, maybe get AltitudeVario thrust mode working with it.

GPS needs mags and mags needs all the high current wire pairs twisted together.  Flight data "system health board" should have all green (or black=unused) with no orange or red.  Mag is hardest to get green.  Mag calibration is always gathering data once you start it (not just when you press the button), so you cannot set the vehicle down or allow it close to metal car, etc while doing mag cal.

[Brunosanta]

hello,
I done the suggested steps starting from the beginning, the board orientation is correct thank you very much.
The issue with the quad loosing the height is also fixed - I increased the amount of the degrees for Pitch ( since my battery and gopro makes lots more weight in this axis) I left the throttle curve straight.
Altitude Vario, I also figure out, I reduced the amount of TX input, and I reduced sensibility also did the temp calibration of the barometer. it still hops a bit but it doesn't fall off.

Still one problem, maybe you help me the other cliff or other guys: my quad is very weight unbalanced, cause my bat isnt enough weight to compensate the gopro I have in the front of my quad, for that the quad drifts lots to the front, also to the left. I tried to compensate with the board rotation in the altitude settings, it works, but if I look in the flight data tab obviously it looks lobby sided. would it be possible to force and say, this is where my quad hover straight, show me the image as if it is balanced.

thank you,

[TheOtherCliff]

The I term in PID will (should) take care of any weight imbalance short of something the motors can't do.

Before going further, you probably know that the best thing you could do would be move your battery as much as possible to make it balance.

If it still drifts some way in Attitude mode, you need to adjust GCS -> Configuration -> Attitude -> Settings -> RotateVirtual more until it doesn't.  And this isn't about a weight issue, it will (should) take the same "rotate virtual" with the quad unbalanced as with it balanced.

After you get it hovering and flying low G maneuvers well, you could change the mix from multicopter to custom and (I assume it is front heavy) reduce the thrust on the rear motors according to what telemetry tells you.  Example: If just hovering it takes 30% more thrust (ActuatorDesired->Thrust) in the front motors, then divide the rear thrust (127) by 1.3 and use that (98) in place of 127 for the thrust for those motors.  Not 100% certain this will work completely without looking at the fairly new scaleMotor() function.  It might be better to reduce the output range by the same factor.  You will still have some non-linearity issues with the thrust, but it should might fly better that way.

[Brian]

I would try flying without the GoPro first.  I suspect you have too much weight on one side for for those motors and those 5" props to lift properly.

Just with the weight of the GoPro and battery I think you're getting pretty close to the 50% threshold for weight / thrust ratio, and then and then you have the weight of the quad and you're putting most of the weight of the GoPro on just one pair of props.  You might need to get bigger motors and props.

[Brunosanta]

Hello,
without the go pro it still drifted, I adjusted them the board trim and I got a pitch value -15 and a roll value -8, in that case it hovers perfect ( or nearly). the fact is, the flight data shows it completely loobysided and it is annoying, I still got no way to say, hey this is straight!

I messed around with the mixers, it has shown some improvements, but the reaction of the back motors when I do stick moves really is not that nice.. but it helped!

I suppose I will just live with the flight data image all twisted and live with it since in the real flight the quad is straight!
thanks guys

[TheOtherCliff]

What flight mode are you flying?  The rotate virtual only helps Attitude/Rattitude/AxisLock, not Rate/Acro+.

But even if flying Rate/Acro+, rotate virtual is needed to make PFD, camera gimbal and OSD all level.

If it is set up correctly, then even if the board is skewed inside the vehicle, everything should look good; PFD, OSD, camera gimbal.

It sounds like maybe you are flying in Rate/Acro+ (so rotate virtual does not affect it) and have "rotate virtual" set incorrectly (so PFD/OSD/gimbal is incorrect).