Hello gentlemen,
I just built a new Quadplane and the plane can take off smoothly. First take off in QSTABILIZE, then QHOVER, then QLOITER and the plane can hover stable for a few minutes, but then suddently it flip over toward right and crashed…I never had this kind of problem in all my Quadplanes before.
I have checked again the video and the log carefully, and found that the plane start to flip toward right front (M1 Motor) as if it was loosing power (thrust), but it actually M1 was rotating. According to the log, value of RCout of M1 (Motor 1) is suddently increased much higher, and at the same time the current also increase much higher, while RCout of M3 (Motor 3) is decreasing much lower.
Firstly I suspect that Motor 1 or ESC 1 failed, but when I rearming the Quadplane just after crash, everything was normal. Both motor 1 and ESC 1 are running normal, No strange sound or other abnormal condition. All motor can rotate normal, same as before the crash.
So I still don’t understand what is root cause of this problem…I need help to analyse the log further to solve this problem. Maybe @tridge , @Allister , @geofrancis or other experts could take a look the log.
Thank you very much.
FC : Matek H743 using Arduplane FW 4.2.2
ESC : BL helli based, rating 40A
AUW is 5 kg
Motor is 2814 kv900, with prop.13x6.5
Battery is 4S and works normal after the crash.
I suspect your either overheating your motors or escs, 13 inch props are massive on 900kv 2814 motors on 4s, they should be running 9 inch props they are basically the same motors as you would find on a dji phantom or f450.
Hi @geofrancis ,
Thank you for your quick response, however I did check all motors and ESC just after the crash and they are not hot , just warm a bit. For your info I did Thrust-Power test each motor, ESC and the 13" propellers for a few minutes from 0% to 100% signal to make sure that my power system is good . And the important thing is, I did check temperature of each motor and ESC at 100% signal, and all are ok, no over heating problem. The maximum thrust during my test is about 2200 gram at 100%, while during hover the load of each motor is only 1250 gr, that just about 57% . Furtherrmore, if there is overheating, then all motors will be overheating, but the fact is not like that, all motors are just warm, like normal . If you take a look on the video, it is very clear that the plane is flip toward M1 (motor 1), while other motors are normal. This is something that I don’t undersstand. Anyway, thank you for your response. Any comments from the log??
the problem is you are not running any ESC telemetry so we have no way of knowing if it was a motor, propeller, esc or power problem, all we know is motor 1 lost thrust.
going by the current spikes the propellers are far too big, your spiking to over 80 amps. I think the ESC has just lost sync due to the abnormal loads on the motor.
when motor manufactureres give you a propeller range, that range is dependent on voltage and weight, they rate it for a 13 inch prop only on 3s and only on machines up to about 1kg. on 4s the motors spin much faster and need smaller propellers or the current consumption will start getting out of hand causing motors to desync or overheat.
I think if you drop your propellers down to 10 or 11 inches your problem should go away.
I’m going to agree with @geofrancis. Motor 1 suffered a loss of thrust. The 80 amp peak occurred just just before the thrust loss, so if everything works when you tested it afterwards it’s possible the ESC got too hot shut down, or there was some other kind of fault related to the high current.
@Allister@geofrancis
I think I realize that very high curent is the main problem, so solution is to change the power system so that the current is much lower than previous condition. Thank you very much for your help to analyse my problem…
Tony
