ESC Problem, calibration or faulty ESC?

[BorisN]

Hi,

We're having problems with our quad, the motors don't run as we expect them to run. The first video shows a jerky flight, and the second one shows the left rear and right front motors misbehaving (Red legs seen as front). Anyone familiar with this problem? Should we recalibrate or look for mechanical failure in the ESC's?

[waltr]

1- looks like the min_throttle value is a bit too low. What is it set to?
2- Once it lifts off there is an oscillation. This can be:
a. Prop and/or motors out of balance. Check and balance the props and motors.
b. The Roll & Pitch 'P' or 'I' PID values may be too high. Once the props/motors are balanced then decrease 'P' then 'I'.
This is just tuning the PIDs.
3- The copter is also still in the ground effect prop wash. It needs to be at least 2 meters high to get out of the prop wash.

Other than that everything looks ok.

[BorisN]

Thanks, we've worked on the problem and found that the left rear motor gets a lower input signal all the time, and decreases even more over time. For example on full throttle it gets 1800 in GUI then within a second or two falls back to 1400-1200.

Furthermore, when checking the AUX inputs and their mapped functions the FC seems to randomly select Angle mode even when there is no AUX bound to the mode. Have you ever experienced this?

[waltr]

I haven't seen that issue but:
What FC board are you using?
Which Firmware did you install?
No one can guess of what the Angle mode issue is without this info.

If the copter is NOT IN THE AIR then the motor speeds will NOT be steady.
Read thew MultiWii WIKI, beginner's troubleshooting.