I recently changed the motors on my 450 mm quadcopter and when trying to fly it for the first time, I encountered terrible shaking and vibrations when the throttle was increased to around 50%. Here are two videos of the shakes: this and this. If you look at the orange vibration dampener plate under the Pixhawk, you can see the vibrations fairly clearly. For reference, I am using EMAX Pro 2810 1150kV motors with a 5200 mAh 3s Lipo battery and 35A Flycolor Raptor 5 ESCs. The flight controller is a Pixhawk 6C. Previously, I was using 2212 920 kV motors and the drone flew, but the motors were being overworked due to my drone’s weight and so I decided to upgrade the motor.
I did not try and takeoff as the drone felt very unstable and I did not want to damage any parts. Is there a fix for this? My initial thoughts are the motors I bought are broken, or that the ESCs are being overworked when the throttle is increased and this is causing some issues. Could it be from bad weight distribution? A bad frame? Bad PID tuning? If there is any information about this issue or ways to fix it in the Arducopter parameters please let me know.
Here is a link to the bin file of the flight test: this.
The Pixhawk 6C has some internal vibration dampening and it should be solid-mounted.
That whole structure on top was shaking, and you will need to do much more to stiffen up the whole frame and all structures. All wiring needs to be secure.
Balance the props too. Even the motors could be out of balance, you can use MissionPlanner motor test to run them without props to see if any are causing vibrations.
There is no quick fix in parameters, the frame has to be solid before you advance to tuning.
Your motors are being commanded to near maximum, but that could be related to the oscillations. So after the physical fixes, we will know more, but dont be surprised if those props and motors struggle with getting airborne and staying airborne in a stable manner.
Thank you, I will try to secure everything more. The thing is that this drone flew well and smooth when I had the 2212 motors on it, and the only thing that has changed with my build is the motors (and now the shakes are happening). This is leading me to believe that the motors are the issue. But I will use the motor test, balance the props, and secure the wirings to see if that changes things.