I've managed to get my ac together and in nice trim. It is very smooth to hover, but i have two weird issues with flight.
First one is with forward flight; in stabilize, simple and alt hold modes when i start to accelerate forward, the copter suddenly turns 90-180 degrees to either side around z-axis after short flight.
You can see the issue in video i posted (vid is compilation, about 6 min, this problem is seen in about 4:30, and hey, nice Finnish views too!).
Another issue is with loiter. The loiter radius is about 10-20 meters, gradually increasing, the copter seems to fly rectangular pattern which expands after every turn. Eventually the copter shoots really fast out of control.
Any help is appreciated.
fw is 2.0.42
I've never had this problem before, but I've heard about it from others. I think it's an uncalibrated compass.
Fly around a bit and then disarm the copter. Disarming will save the compass calibrations.
If you want to verify it's the compass, disable it in the CLI Setup menu. "Compass off"
I have seen this before in one of my quads and posted about it. I was playing with PID's trying to get rid of the 'springy' yaw i still see today.. When i had the yaw stabilize P down to low all i had to do was a bit of forward flight in any direction and the yaw would spin 90-180 degrees or more. I reverted P to higher value and it went away, wierd. I cant explain it and have not sen it sense (but never lowered my P since).
just my two cents:
1. I had motors just like yours once. Even the prop holders looked like yours.
Problem: This setup makes the motor shaft very long. So if the shaft is even a tiny bit unbalanced this will have a huge impact on vibrations. I had exactly this problem. My copter (about one year ago it was a Mikrokopter) wouldn't fly in a streight line.
Different motors with a differnt prop holding system: problem solved
2. In your video I hear a really loud, strange sound as soon as you try to fly forward. Maybe there is just something wrong with your front-left motor.
...just a guess
I hope you can solve the problem.
You do have a magnetometer installed, yes?
Your video says compass... but maybe something is not working? And when GPS speed gives a vector, it rotates?
I also wonder about the balance of your props; odd noise and you can see the motor being wobbled from the sticker movement, mostly on the right, but also a little on the left prop in the video.
Congrats on the good flying. Pretty good video.
Actually the motors don't wobble, checked it with ac secured to table. The wobbling is jello effect in video due to slight frame vibration. Yes, magnetometer is installed.
Any suggestions for prop holders? Ones i use now are stock holders that come with arducopter motors with aluminium cone replaced with nylok-fasteners.
Ok, changed one of motors and tweaked yaw stabilize P back and forth, it seemed to be ok, but...
Uploaded this vid, almost lost the copter, whew...
Sorry, I have almost no yaw tuning experience. My only yaw problems came from not reading the manual and flying without a magnetometer. From that experience, I test my compass to make sure I did not install it upside down, or front-to-back, and I use the Cli to verify that I am getting good data from it, then I use a physical compass to make sure the quad knows which way is north. I check approximately also as part of my pre-flight check because twice I have seen it reverse directions 180 for reasons I cannot explain. I moved the quad about 5 feet, restarted it, and it was normal again. I had a theory about magnetic interference during boot, but I do not know if that theory holds water.
Magic. I uploaded 2.0.44 and everything works. Perfect. :)