My hexacoter pitch down when I taking off

Hi, I set up my hexacopter yesterday and when taking off the copter was pitched down so that the blade can hit the ground so I decided to abort the flight. Could you guys help me? and today I decided to recalibrate the copter could you review the log I think there’s something strange with the motor RCout log.

here’s my yesterday log
https://drive.google.com/file/d/1_CEAbp0--yW4Wbd6DNdrgDT_sgOykFMn/view?usp=share_link
https://drive.google.com/file/d/1rgWYWhcxsWSGVcu5ZvQEJUxvkXID_Fru/view?usp=share_link

And this is my to-day log
https://drive.google.com/file/d/1pxtfpNT_rPyN-GcOhQI23-xLWijCjtnz/view?usp=share_link

I only looked at the Today log. Is the drone tied down?

Have you done a motor test using mission planner?

Rule 1 : MissionPlanner motor test
Rule 2 : when you think you have got it right, see Rule 1

Strongly advised to have props off! Put a bit of tape on each motor shaft with some tail sticking out, so you can see the spin direction.

In the motor test, the “Letters” are in a different order to the motor “numbers”

  • A is always front right, so motor 5 in this diagram.
  • B is next around clockwise, so motor 1 in this diagram

…and so on around the circle.
Do the “all in sequence” for the final check.
image

yes I already tested the motors with motor testing in the mission planner

I’ve checked everything is correct

Go over Shawn’s notes because he provided a much more detailed answer than I did.

In the log I looked at the motors reached full speed but the drone hardly moved. So again I ask: is the drone tied down or are the props removed?

If the motor test works exactly as Shawn has described then you should be able to move on, and if it’s pitching or rolling we can look for other reasons. But history around here has us biased because 99% of the time this issue comes down to motor positioning.

If the drone is tied down then how the drone reacts when the motors are running is irrelevant. The PID loop will not react properly if the drone is not free to move as required and anything is possible, likely not what you want.

yes I removed the propellers and I test by changing copter attitude when I arm in pos hold mode the motors look alright

Use the motor test function in Mission Planner. Just moving the drone around may be satisfying but it is pointless.

OK, in Radio calibration, check the operation of the pitch stick and the green bars onscreen.

Copter/Ardupilot pitch is opposite to how you expect it to look onscreen.

  • Pull back stick (climb), green Pitch bar goes up to maximum PWM
  • Push forward stick (dive), green Pitch bar goes down to minimum PWM

You may have to reverse the operation in your transmitter.


I make a generic model I can just copy and rename when I need a new model, that way all those tricky settings are already done.

EDIT:
Also, level the whole frame of the copter across the tops of the motors in every direction (quite precisely too :slight_smile: ) and go to MissionPlanner / Mandatory / Accel
and click on Calibrate Level