The drone topples immediately during takeoff (loiter mode) as soon as throttle is increased.
The vehicle does not gain stable lift and flips within the first few seconds of spool-up.
Frame: Quad-copter (X configuration)
Motors: Hobbywing X9+ (100KV)
Propellers: 36 inch
Battery: 14S 20,000 mAh
Firmware version:-ArduCopter V4.6.3 (92b0cd78)
FC:- Pixhawk Cube Orange+
I attached the log for your reference; kindly review it and comment. takeoff weight is nearly 45kgs(with payloa
Motor assignments/order is clearly wrong. This is among the most basic steps in configuration. Please do try not fly that thing again until you consult the documentation and configure it properly. You’re going to hurt someone.
Before this flight , I tested the drone with default PID gain values, but it was unstable. I then reduced the gains by 10–20%, but the drone remained unstable.
Please check the attached flight log and video for analysis.
Before crash :- before crash log
video link :-before crash video
After that, I learned about QuickTune. I reset all parameters to default and complete
RC Calibration
ESC calibration
Accel, compass,level, GYRO and Pressure calibration
and then attempted the takeoff for quick tune . During this flight, the drone crashed on takeoff.
Has the drone flown before? Or is this the first flight?
Before the crash, I flew the drone almost 4–5 times
You must not use Loiter mode until the PIDs are tuned.
So, as you have found out, using loiter mode to do the first quicktune is a bad idea. And bad ideas tend to cause crashes.
In the future only use stabalize mode, until you set the altitude PIDs.
After the altitude PIDs you can start using AltHold mode.
After you have done Notch filter, quicktune and MagFit you can start using Loiter mode.
Reduce the PIDs again and fly in stabalize mode only.
I’ve read the initial post more carefully.
This is a 36’’ vehicle!
It is irresponsible to configure this vehicle without using AMC
Thanks for the response.
yes 36 inch vehicle.
Can you confirm whether the reason for the crash was a flight controller hardware failure or not a motor issue? This will help me start my testing
I do not have the time for that.
I use my time to improve the AMC software, so that is is as easy and safe as possible, for as many users and use cases as possible.
You cant just take your first flight by randomly adjusting some PIDs, and must never use loiter/Althold initially at all. Keep in stabilize only.
And yes definitely, as @amilcarlucas, @Yuri_Rage Sir said, this is a BIG vehicle, and you should definitely follow the procedure of Ardupilot Methodic Configurator to tune this fully, otherwise this might get fatal
If your drone is really behaving unstable for now, Then I would recommend to reset all params to default, and then start from the beginning, following all instructions here =>
Above is the instruction set which made my drone very stable, even in the first flight.
.
Btw, that’s the “Copter Firmware version”, not the “Quadcopter Flight Controller”. Mention the name of your FC there.
Go back to the first post.
Edit: I see the drone is already on default parameters. This drone will not fly in loiter mode on defaults. A crash is to be expected. @mukesh You have been given good advice to use the AMC. I would agree with that. Follow the procedures very closely. You have a lot of money on the line here and just pushing forward without using a proper procedure will waste it all.
it seems to be configuring issue rather than hardware.
if motors dont get hot and if they respond fine from motor test, and your fc is correctly showing motions in hud and sensors respond fine, it is most likely issue with configuring/tuning.
the cube orange has more than enough redundant sensor and it is almost impossible that all 3 imus fail together.
from the video you shared, it looks extremely unstable and you should have landed with seconds. It almost toppled over once. either you dont know how a proper tuned drone flies or you just dont care.
Wow that video was hard to watch.
Configure fully with amc, then test in stabilize.
@Ishitbh No it’s not that he doesn’t know how a proper UAV flies/or he just doesn’t cares.
It happens. We all as beginners want that our quads be equipped with advanced up to date future proof hardware and it flies like a dream. But Beginners really don’t know that software matters even more than the hardware.
The understanding develops through researching/reading/solving problems.
@mukesh You have faced a problem and gained a lot of new hands-on experience for why exactly is tuning params/Doing things Methodically, necessary. Go and start with reading general ardupilot docs/AMC docs/Reading the problems faced by other Builders here.
I would really like to appreciate you when your Large sized quad flies stable at high altitudes/does the work its made for. 
Get a smaller drone and learn how to do this. Starting with that monster….
Put the same kind of stuff on a 7” and really learn Ardupilot. Then do it again with a 10”.
Hi @amilcarlucas I have completed the tuning with AMC Software. Now the drone is flying and its stability is good. We are facing only one problem, when we give pitch forward or backward commands, the drone loses altitude. Could you please review the log and comment the solution.
Flights logs:- https://drive.google.com/file/d/1MHrjujSH5R_GFQOLVeBNp5rOxgWg8i6w/view?usp=drive_link
In Loiter or AltHold flight mode? Then you have a baro pressure issue. It must be solved in hardware using foam to cover the barometer.
And post the .zip file generated by AMC when pressing the “Zip files for forum help” button.