Hi @Stefan-Amundarain ,
Thank you for uploading the video with the detailed demonstration.
What I see from the video is that the initial "sinusoidal" spin-up works (almost) every time, but the ESC fails to transition to regular non-sinusoidal control mode. There are typically two reasons for this:
a bad motor / wiring / connection or one of the ESC Mosfets is not working properly. In some failures, the sinusoidal spin-up is still able to rotate the motor, but during the transition to normal operating mode, there are some checks to ensure proper motor behavior and if those checks fail, the ESC stops (and then restarts since you are commanding it to spin). The behavior i am seeing is very similar to this.
sometimes if you have spin-up time too fast (and spin-up power too low), the ESC will lose sync with the motor during sinusoidal spin-up. I would suggest trying to (you can do both changes at once):
increase the spin-up time (double it from what you have now)
increase the spin-up power by 20% (if it is 100 (which is 10% power), set it to 120, so it will be 12% power).
also double check that the motor kV is set correctly, because it is used during sinusoidal spin-up for back-emf compensation.
I would also suggest swapping out the motor for an identical new motor, so you can eliminate the motor being an issue. You can also check the motor winding resistance to make sure all 3 possible pair-wise resistance measurements have the same resistance.
Finally, if all of these steps fail, please try to use another ESC channel to see if it is a dead ESC channel (which should be unlikely).
Please try these out and let me know what you find!
Alex