Moror rotation speed unexpected behaviour on test bench

[cramredan1]

I'm experiencing a very strange behaviour that prevents me going further on the field.
Maybe I'm wrong, but iNav users will for sure put me back on track!

I swapped a KakuteH7/Ardupilot board with an Mateksys/iNav board on a small 3" Cinewhoop quad.

I notice a big difference between their behaviours on the bench (without any props) at arming time and increasing throttle.

• On my KakuteH7/Ardupilot, all motors are spinning the same speed until they reach the hover point at around 1400µs throttle. This seems correct to me and the drone flies well.

• On the Mateksys/iNav quad, motors speed start to engage at high rates and unevenly from 1100 to 1400µs, and then to 2000µs (max input range).

I suspect something weird, but cannot figure-out what's going wrong with this configuration.

Should anyone on this thread have a clue, you're more than welcome to suggest any idea.

Marc

Below are some accompanying captures of the culprit (taken without props on the bench)

Throttle at arming

Increasing throttle from 1100 to 1400µs

Reaching full throttle (2000µs)

[sensei-hacker]

What flight mode are you in?

What you described is consistent with the following scenario:

User puts a quad on the bench

Quad is angle mode

The quad, bench, and floor level is such that motor #3 happens to be the highest, being 1mm higher than motor #2 and 2mm higher than motor #2.

Since it's in Angle mode with the sticks centered, it tries to level out. Motors 1,2 and 4 spin, trying to lift those sides of the aircraft.

Bottom line - to test the motors, use the motor sliders in the Outputs tab. Don't try to flight testing without flying - that path leads to madness.

[cramredan1]

You where right Sensei... I was starting-up in Angle mode... I understand now.
Following your adivse, already tested the motors sliders. Rotation/Speed seems ok.
Going on the field...