Initial Parameter Setup

ArduCopter Copter 4.6
1

Hi everyone,

I have just completed my first Hexacopter build and I am preparing for the maiden flight. Since I am new to the ArduPilot ecosystem, I am following the documentation and using the ArduPilot Methodic Configurator to ensure a safe setup.

However, I am a bit confused about the values suggested in the Initial Parameter Setup. Here are my build specifications:
My Setup:

  • Frame: Hexacopter (S550)

  • Weight: ~2.5 kg (AUW)

  • Motors/Props: DJI 2212 920KV / 10x4.5 Props

  • Flight Controller: Pixhawk Cube Black

  • Battery: 4S Lipo 5200 mAh

    I entered the neccessary values into the methodic configurator and missionplanner , I noticed some significant changes in the filter parameters. The methodic configurator and the missionplanner set up the same values.

init-params
init-params1918Ă—1078 309 KB

But i can’t be sure of three parameters which are; ATC_RAT_YAW_FLTD, INS_ACCEL_FILTER and INS_GYRO_FILTER.

My Questions:

1) INS_GYRO_FILTER (42Hz vs 20Hz): The configurator suggests increasing INS_GYRO_FILTER from the default 20Hz to 42Hz. While I understand this reduces latency for smaller props, I’ve read on the forums that larger or mid-sized builds might suffer from oscillations at 42Hz, and the documentation often suggests staying at 20Hz for the first flight. For a 2.5kg Hexa with 10" props, is 42Hz safe for a maiden, or should I manually revert it to 20Hz?

2) Dependency on Gyro Filter: If I decide to keep INS_GYRO_FILTER at 20Hz for safety, do I also need to manually adjust the dependent parameters (like ATC_RAT_YAW_FLTD, ATC_RAT_RLL_FLTD, etc.)? Or is it okay to leave the derivative filters at the values calculated for the 42Hz setup? Because these parameters are adjusting with INS_GYRO_FILTER/2.

3) INS_ACCEL_FILTER (20Hz to 10Hz): The setup suggests lowering INS_ACCEL_FILTER from 20Hz to 10Hz. Being a beginner, I’m worried this might make the copter feel “sluggish” or affect the attitude control. Will this change cause any difficulties in controlling the drone during the first hover test?

4) ATC_RAT_YAW_FLTD being set to 0: I also noticed that ATC_RAT_YAW_FLTD is set to 0 by the configurator. I know that for Roll and Pitch, this filter is crucial to prevent D-term noise from heating up the motors. Is it normal for the Yaw axis to have this disabled (0) by default, or should it follow the same logic as the other axes?

I want to make sure my maiden flight is as stable as possible to avoid any early mishaps. Any advice from experienced builders would be greatly appreciated!

Thanks in advance!

2

Default PIDs are fine for 10", suggested initial parameters are safe. Cruicial is to setup RPM filtering with bidirectional dshot data.

3

It is very safe to use 42Hz.

Use the values from the initial parameter calculator.

No, that is safe. 10Hz is recommended for all vehicle sizes.

Keep it at 0 for the first flight.

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4

I entered the correct values, including the propeller diameter.
I already mentioned that there is no difference between AMC and MP.
Because of the reasons I mentioned above, I wanted to consult you because I was unsure about the values ​​at which the filters were set.

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