I am building a tri arrangement vtol. ECALC predicted maximum 19A per motor with the given prop and battery arrangement so I used some 35A cloud phoenix blheli32 ESCs.
A bench test impressively confirmed the max current as 19A using a PWM servo tester.
Today I tried the first ‘gross error check’ hover test. After about 30seconds hover a front motor stopped and it fell about 1ft without damage. One ESC was dead but came alive after a power cycle. I checked the logs and there was a maximum combined current of 40A with an average of 31A. I checked all connections and tried again. Same again except it was the other motor.
I checked blheli settings and stupidly removed the current limit (as it was not possible to go over 19A on the bench).
Flew for a 3rd time. This time both front motors stopped at the same time but the frame did not get damaged. This time one ESC smelled of burning and had melted one of the 3 motor solder joints. These 2 front ESCs are not not working properly. The front 2 motors are more heavily loaded than the tail motor but not by much.
So question.
Can an FC using DSHOT 600 cause the ESC to use more current than with a servo tester on PWM? Sorry didnt make a note of the blheli settings yet.
Motor is a MT4008-12 with a SF 14x4.7 prop (just for this hover test) on a 4s Liion.
Any ideas? Im thinking a timing issue fight with dshot and blheli settings.
1 post - 1 participant
