Hi -

I am beginning to test a new 10" build. My maiden flight used the default Betaflight PID's. The quad was "wobbly" in Acro mode and very unstable in both Angle and Horizon modes. This was not surprising since the default PID's assume a 5" frame.

Before I begin the tuning process, I was wondering if anyone could suggest a default set of PID's that can be used for a 10" quad?

Build specifics
Frame - 450mm polycarbonate
FC - Kakute F7 stack with Tekko32 4in1 ESC
Motors - EMAX 2213-935kV
Props - Master Airscrew 10x4.5

The Betaflight settings are in the attached JSON file.

i would start with 30% increased pid values, i beleive you will need to increase them even more.
as its power to weight ratio is mich less than a usual 5inch, you will need mich higher values on your build.

(16-Aug-2020, 08:21 PM)hugnosed_bat Wrote: i would start with 30% increased pid values, i beleive you will need to increase them even more.
as its power to weight ratio is mich less than a usual 5inch, you will need mich higher values on your build.

Thanks for advice. I actually decided to try iNav for next flight. INav has a default configuration for 10" quads. Flight was better but there is still some wobble but it was possible to use all flight modes. This is a video of flight in Horizon mode with altitude hold.

(17-Aug-2020, 04:26 PM)navillus5 Wrote: Thanks for advice. I actually decided to try iNav for next flight.  INav has a default configuration for 10" quads. Flight was better but there is still some wobble but it was possible to use all flight modes. This is a video of flight in Horizon mode with altitude hold.

What version of iNAV has default configs for 10"? I have been looking at iNav 3 and it only goes up to 7"

In case anybody stumbles on this thread...
1. 9"/10" is not as forgiving as 5"
2. Betaflight defaults suck
3. Regardless how much $$$ you spent, your frame is likely not stiff enough. 7.5mm min. Anything less will be tuning nightmare. 
4. Uavtech preset is about: P70 I90 D90 FF170 https://theuavtech.com/presets/
5. For sure, lower Iterm Relax cutoff below 10. 5 is good.
6. Do NOT raise filters. If anything, might need 0.9x on sliders.
7. RPM filters is a must.
8. Make sure props are balanced. And frame screws tight. I can fly back 5" with broken prop tip or even half a blade. On 9/10" thats suicidal, and will bake motors/magnets in 200C+ 
9.  I only have this one 9/10", but from what I have seen, in general P/D ratio close to 1.0, and lower I term. 
Some people push PID to 60-70s, but I already see motors saturating in 30s. This depends a lot on prop and motor.
I have Avenger v2 2812 which is certainly SMALL for 9". With Xing2814 or 3015 can push PID much higher.