Weird sound from a scorpion sii 4035 motor

modyy hesham

New member
We are testing this configuration :
Scorpion sii 4035_380kv
12*8 apc propeller
4 pack in series 3s 2200 mah lipo battery each = 12s
Scorpion Tribunus 12-130A ESC
I tested it more than 10 times with no problem but after that every time we hit 60% throttle or higher (more than 35 amps) the motor make a noise and we didn't know what is the reason for it.
We have the system (motor/esc/propeller ) but untested (new) so we assumed it was a motor problem so we changed the motor with the untested one but we hear the same noise so it wasn't the motor so we tested the new motor with the new esc and we hear the same noise also.(yes we hear the voice with the first test of the new configuration)
We tried every possible configuration but every one make the noise (we thought that we damaged the motor or the esc but we tested the new ones that never been used)
Is that a battery problem?!
Anyone has an answer or faced something like that?!
I uploaded the video of the test on youtube this is the link of it :

Thanks in advance


Site Moderator
Staff member
Hard to tell from the video, is it possible the sound is coming from the prop flexing? Might try a carbon fiber prop.