CG or Gains?????

[Mav]

Hey guys I built my second multirotor yesterday after having what i think was a fly away with my 450 running naza lite. I upgraded to the M V2 and an F550. This is my first hex so I'm not sure if this is common flight characteristics of this craft but i expected it to be much more stable flight. The 550 rocks front to back on the pitch axis. Example, if i fly forward and let go of the sticks and let the flight controller stabilize, it rocks like a pendulum effect. The wind will also cause this. I do not get this on the roll axis. I am thinking it may be a gain issue on the pitch axis. But I installed the photoship one landing gear on it which has a long gimbal boom and you counterweight it with a rearward battery placement which is also on a boom, so I am thinking this could be causing the pendulum effect. The CG is dead on front to back, but it is obviously out of balance top to bottom because of the landing gear, gimbal, and battery being all on the bottom. So is this a CG problem or gain issue? Please help me get this thing to fly as good as it looks.

View attachment 17526View attachment 17527

 

[Mav]

CG or Gains????

CG or Gains?????
Hey guys I built my second multirotor yesterday after having what i think was a fly away with my 450 running naza lite. I upgraded to the M V2 and an F550. This is my first hex so I'm not sure if this is common flight characteristics of this craft but i expected it to be much more stable flight. The 550 rocks front to back on the pitch axis. Example, if i fly forward and let go of the sticks and let the flight controller stabilize, it rocks like a pendulum effect. The wind will also cause this. I do not get this on the roll axis. I am thinking it may be a gain issue on the pitch axis. But I installed the photoship one landing gear on it which has a long gimbal boom and you counterweight it with a rearward battery placement which is also on a boom, so I am thinking this could be causing the pendulum effect. The CG is dead on front to back, but it is obviously out of balance top to bottom because of the landing gear, gimbal, and battery being all on the bottom. So is this a CG problem or gain issue? Please help me get this thing to fly as good as it looks.

 

[Benjamin Kenobi]

Sounds like gains. What gains have you programmed in? And what gains does the manual tell you to program in?

 

[Mav]

i have not changed the gains at all so they are at default that comes with the V2. My manual says recommended gains for the F550 are:
P 170
R 170
Y 150
V 140

 

[Mav]

I also wanted to say thanks Ben as you are always answering my questions. I think it might be worth mentioning that the value i have entered for the Z axis is -9, which is the distance from the top plate to the center of the GPS. I feel that this number is probably off because I am now realizing that isn't where the CG for the Z axis is but I also don't know how to find the CG for that axis

 

[Benjamin Kenobi]

I also wanted to say thanks Ben as you are always answering my questions. I think it might be worth mentioning that the value i have entered for the Z axis is -9, which is the distance from the top plate to the center of the GPS. I feel that this number is probably off because I am now realizing that isn't where the CG for the Z axis is but I also don't know how to find the CG for that axis

Anytime. I spend my free time on the forum as you learn so much here. MultiRotorForums.com rules!

I would increase your gains a bit. I believe the default is 100% which would make it look wobbly in-flight. You can try 120% across the board to start with and then adjust them in between flights to see how it reacts. It's a personal choice to get the feeling you want, and it's good to learn how gains affect performance.

Cool?