I have built an FPV drone using 7-inch propellers.
The motor-to-motor distance is 380mm, which is slightly larger than typical 7-inch FPV drones.
With the payload attached, the total weight is approximately 1kg (excluding the battery).
The frame is designed with 7mm arms and 3mm plates.
The arms are firmly secured and show no signs of flex or twist.
The flight controller is a custom DIY board based on the F405, and its stability has been thoroughly validated through testing.
The motor wires are connected to the ESCs with some slack to allow for movement, and the FC is mounted using soft dampers to reduce vibrations.
From a hardware standpoint, everything seems to be well set up.
I conducted a short flight test lasting about one minute.
Initially, I performed several throttle sweeps to raise and lower altitude.
Then I moved on to aggressive pitch, roll, and yaw inputs for a braking test.
After the flight, the motors were warm but not excessively hot — I could still touch them without discomfort. I estimate the temperature was around 40°C.
Upon reviewing the flight logs, I noticed that most vibration levels remain below 20, which appears acceptable.
However, I observed significant vibrations specifically during throttle changes, particularly when the altitude is changing.
I suspect this could be due to prop wash — though I am open to other explanations.
The current relevant parameters are as follows:
PILOT_SPEED_DN= 250PILOT_SPEED_UP= 300PILOT_ACCEL_Z= 250PSC_JERK_Z= 5MOT_SPIN_MIN= 0.08
I have tried increasing the MOT_SPIN_MIN value, but it did not seem to make a difference.
I also slightly reduced the ATC_RAT_P values for roll and pitch, but that did not help either.
I would greatly appreciate any suggestions on what else I could try to reduce the vibrations during throttle transitions.
Thank you very much.
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