Kingkong 90GT Review, OSD, Modifications, and Tips
I flew my 90GT for about a week and found this to be a terrific quad. While initially flying it indoors, I found that it was underpowered and the stock PID's were pretty sloppy. Admittedly, I upgraded it to Betaflight 3.1.7 (from 3.0.1) and applied the same stock PIDS before flying it for the first time. It became a much better flier once I started increasing the PIDs. But, without a Minim OSD, tuning this becomes tedious.
The stock props with the prop guards installed were less sensitive to PID tuning. At one point, I had the P's over 70 without much change. If you crash hard enough to bend the prop guards enough for the props to hit anything, they will shatter very easily.
I took off the prop guards and switched to DYS 2030 props. This change improved the performance incredibly. I had to decrease the PIDs a lot in this setup.
Here is my tune so far. This still has a little roll oscillation when pulling out of dives or fast turns at low throttle.
NO PROP GUARDS & DYS 2030 props
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set gyro_lowpass_type = PT1
set gyro_lowpass = 90
set gyro_notch1_hz = 0
set gyro_notch1_cut = 300
set gyro_notch2_hz = 0
set gyro_notch2_cut = 100
...
set d_lowpass_type = PT1
... MY PIDs don't work super well. I have been trying to get a good tune. Now that I have it flying again, I'll see what I can do to get some good PIDs up here.
set p_pitch = 54
set i_pitch = 49
set d_pitch = 58
set p_roll = 52
set i_roll = 49
set d_roll = 58
set p_yaw = 70
set i_yaw = 45
set d_yaw = 20
...
set rc_rate = 100
set rc_rate_yaw = 100
set rc_expo = 25
set rc_yaw_expo = 25
set thr_mid = 50
set thr_expo = 0
set roll_srate = 80
set pitch_srate = 80
set yaw_srate = 80
Unfortunately, once I got the OSD installed, I had a crash indoors without prop guards and bent a motor shaft before I could get a tune that I was satisfied with. I will tell you that the Minim OSD draws a lot of power and cuts the flight time to about 3 minutes. But, it is a great tool for tuning. Once I find a tun I like, I am going to remove the OSD for better flight times.
Oscar Laing's Minim OSD Tutorial: https://oscarliang.com/minimosd-micro...