CW and CCW motor thrust imbalance

Hello guys,
I am trying to tune a heavy lift hexa for agricultural spraying. I performed my first flight today and there was considerable difference in the PWM output values of the CW and CCW motors.

I had experienced a similar issue on a previous heavy lift octa build. The frame seemed to have some issues so I did not get a conclusion as to why this difference was present. The consensus was a motor tilt problem. I tried correcting this but the problem persisted.

Now with the hexa I have made sure to adjust the motor level with a spirit level. Yet I have the same issue again.
I have set the initial parameters for tuning based on the octa setup and I can’t seem to identify the source of the problem.
I have attached the LOG file of the hexa flight and the PARAM list as well.
Any help you guys can provide will be appreciated.

The first obvious question is what props are you using?
I have had some real discrepancies between CW and CCW in the past.
Do you have a way of checking thrust from those props?

Have you worked through the tuning page?
Your desired v actual is looking a bit off.

Frame design would be the next thing to look at.
How much aeroelasticity is there in the frame?

I am using the EFT E610S 10L frame with hobby wing X6 motors and 23 inch props. The frame doesn’t seem to have any discernable issues on the ground and in flight.

I haven’t checked for the thrust of the individual motors, I will try to perform a bench test.

I haven’t gotten to the tuning yet. I have set the initial params based on the tuning process instructions and performed the first flight.


I was unable to conduct many flights due to the COVID restrictions. But I did manage to conduct the bench tests and there aren’t any major differences in the thrust generated between the CW and CCW motors.
Furthermore, I have setup the hexacopter from the beginning and done the initial flight.
Here’s the LOG for the same.
The problem still remains.
I played around with the yaw PIDs and yaw filters, with no luck.
I am at my wits end with this, so any help would be really appreciated.

I suppose it must be still be that the motors are not level. Could the arms/folding mechanism be twisting under load? If you are not getting Commanded to max outputs or Loss of thrust messages when fully loaded and running a typical spray mission perhaps you will just have to live with it.

I haven’t observed any twisting in the booms, and the motors are set straight with a spirit level.
It might be something with the parameters as there was a similar issue with a previous octa build.
I will try tuning it and see how it goes nonetheless. Thank you.