May I know the issues with the hardware…as we directly mounted motors to the arm and there is no twist in the motor mounts. We manufactured the carbon frame and arms inhouse. Please let me know any issues in hardware.
I am not an expert, but the four bolts which retain the arms to the main body are too close together. I would try and put them as far as possible, i.e. you can spread them by a few milimeters closer to the edge of the arms and certainly separate by 1…2 cm in the longitundinal sense.
Obviously, one can not tell visually if the frame is rigid or not, it may well be that it is rigid enough, but just by increasing the separation of bolts you could obtain roughly the double rigidity…
Also perforating arms at midpoint for the legs is the worst place where the bending stresses are st maximum. I would put the legs much closer to the motors. But again, that issue would not be the cause of tuning problems.
Every flight you make different modes appear and disappear. Make a simple hover flight in AltHold for 1 minute and use that to set the Notch Filter.
Doing this is pointless unless you are tuning the Pitch Rate:
And if you want to do that use In-flight/Transmitter based tuning. This assumes you would abandon Auto Tune.
And I have to agree with @Michail_Belov on the rigidity of the arm mounting. This kind of looks like an X-class frame so check-out how TBS does it with the Source X Frame.
Thank you. The distance between the bolts sticked with frame is 20mm x 15mm and bolts are near to the arms. As we did drop test and check the rigidity by physical inspection. It is rigid and no resonance created. But even though it is rigid but what making the tuning to give the poor gains.
I did a hovering flight ,analysed and applied filters then followed instructions. Did autotune at roll axis the angle i got is 3.4 where as in pitch axis 7.2. Filter worked well in pitch axis but not in roll. I will try to do one more autotune on roll axis and check whether it gives good value or not.