Unstable take off. Hexacopter with X11 Plus

ArduCopter Copter 4.6
1

Hi guys.

i built a little big drone :slight_smile: i m using default parameters and initial tune parameters. Motors, props and platform are straight. i did acc and compass calibration well. i m using 2x gps with disabled compass. i m using only internal compass from FC. well balanced CG. total weight almost 80kg with batteries. Using Motor İnterlock for safety.

Motor pwm set to 1050-1950

Throttle range 1040-1950
Radio sticks centered.

Radio calibration, motor orientation, prop rotation, stick response done.

My setup;

Cuav x7+ pro

2x Neo 3x Gps

6x X11 Plus motors 43x14 props

Total 14s36p li-ion pack.

Here is the logs and take off video.

(tlog is long. you can check last %10 percent)

Drone doesn’t seem to be leveling itself, or it’s doing it very slowly. am i right?

2

To configure big heavy drones you need to follow checklist procedures to make sure you do not miss a step.
Is the ESC RPM telemetry configured correctly?

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3

i m not using esc rpm telemetry. Just connected via pwm.

4

This is not a hobby vehicle, this is an expensive professional vehicle.
The Manufacturer specs are PWM 1100-1940, correct that. And add ESC RPM telemetry.

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5

might not be a really good idea

also might not be a good idea

you should probably want to run magfit once it flies little better and then notch filters, quiktune/autotune

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6

On such big vehicles is irresponsible to not use something like AMC

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7

Manufacturer says 1100-1940. But when set pwm to 1100, motors not working. only working with 1050us.

İ will try AMC today. But do I absolutely need to use ESC Telemetry?

8

You plan to put payload on that copter, right?
You plan to not measure the Propulsion system in a trust stand, right?

If both answers are yes, you need ESC telemetry.

9

Correct it to 1100-1940 and then correct the MOT_ARM_SPIN parameter.

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10

Sure. i will do that. i will set offset parameters from Magfit too. After that, i will get parameters from AMC right?

11

AMC is very well documented. You need to read and follow the instructions it presents you.
This is an expensive machine, read the instructions carefully, and ask questions.

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12

if i calibrate external compass without mounting on drone, (i mean calibrate sperately from drone frame) is it work correctly? because drone is very large.

13

No it will not.
As AMC says: All components need to be assembled, except the propellers for steps 05-18

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14

drone has some interfering materials like soft iron and mounting imperfections so calibrating outside will not work.

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15

amc is step-based and it helps in everything from hw setup to final touches.
go step-by-step. only you may skip the initial steps of like imu calibration etc which you know are correct. do the other steps

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16

@amilcarlucas AMC saved me. What a beautiful helper. Thanks a lot man. Good job.

2nd take off successful. Here is the take off and log files. Based on herevit x11 template. İ will continue to tune tomorrow. I m waiting for your advices :smiling_face_with_sunglasses:

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17

You’re welcome. Glad it helped.

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18

i will test AltHold and loiter modes tomorrow. but its huge bird. so i don’t want to do anything wrong or leave anything incomplete. Can you give advice based on the logs for more stable takeoff?

Are there any parameters I need to change before applying autotune?

I can’t draw any conclusions from the logs. Could you do a simple analysis? ArduPilot has changed a lot since I last used it. i need some advice from Masters before next flight.

@dkemxr

19

You only posted a .bin file. You did not post yet the .zip with the AMC configuration files:

image
image661×433 100 KB

20

I don’t know where you are in the AMC but the attitude stability is very poor. It must feel very sluggish in flight. I highly doubt Auto Tune would run w/o failure to level errors in this condition.

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