I’ve been having a great time recently on my second version of a prone foil board with built in foil assist. It has been running brilliantly up until a bit of a nightmare today.
I initially noticed intermittent signal failure between the Maytech remote and the receiver despite the remote having good signal. I decided to paddle in to see what was happening and as I did, I looked down at my hatch as a mini explosion of black smoke occurred.
The Flycolor xcross hv3 160a esc is toast. The live presoldered wire is completely detached, as are the signal wires. In addition a small chip on my matek UBEC is fried.
Would people on here mind speculating what might have been the cause?
I did use a different battery pack today. Same configuration though (12s2p with p45b molicel cells) as I have been using previously.
I’m keen to try to get to the bottom of this and then work on ways to try to prevent it and get back out there enjoying myself.
Interesting, i think i saw some other user doubting the matek becs here (@Jesserosco ?)
To know better what actually happened you’d need to show exactly what broke both on the esc and in the bec with high resolution pictures showing the PCB:s
It’s beginning to add up with the popped flycolors, could there be a design flaw or something as easy as a short through the cooling pad to heatsink?
I think @hangloose replaced those on his flycolors to get better packaging. Maybe there was something visible?
Not really, we’d need clear enough pics to read the component numbers and follow the broken pcb traces, and some detailed descriptions what is damaged.
On the matek seems simple, for the esc it seems one of the capacitors have popped but i don’t think this can desolder the battery line. Are there any traces of the battery leads being shorted to each other somehow?
You might as well separate the esc parts and clean it to get a better look what has happened, if there are popped mosfets and other components under the heatsink.
This looks a bit sketchy, might not be related to the issues but easily checked. Even a momentary contact between the motor phases can damage the esc, and one of the phases also looks too tightly bent and could be broken.
I have zero evidence to substantiate my claim of the BEC to be at fault, but I have had issues with RX connectivity and destroying my RX boards. I asked @ludwig_bre about leaving the RX unplugged until after plugging in the battery to avoid voltage spikes and he said it was a good idea. I bought a couple of the beefier mateksys BEC’s, but haven’t tried them yet.
Maybe adding a small capacitor to the BEC could help?
This bigger mateksys bec apparently has a TVS ( Transient Voltage Suppressor) diode and the micro BEC doesn’t so the bigger one seems to have better protection.
Hi James, did you take a screenshot of your XCross settings ? Just wondering if you were running the current limit function. There was some talk/theorising about the current limit function causing spikes that could possibly heighten the risk of bec failure. No idea whether that’s the case, just wondering what your settings were. Thanks
To me it’s pretty obvious a high voltage spike popped both the eac and the bec. The only way the caps pop is over voltage or burn out with too much current.
I’ve popped both an HV bec (turnigy) and cap on an APD 120 simultaneously as I released the throttle. It seems that sometimes after running full throttle and release you can get a voltage spike.
I had been using this board and set up for 5 sessions prior to this. All around 1.5 hrs long. All with reasonable periods of e foiling in between waves. It had been brilliant. I also have 2 other set ups with the hv3 esc (in the box mounted on top) that have been flawless up until now.
The problem at throttle release is likely to be loss of control of the rotor position. One thing that might help is to set a longer ramp down time for the throttle (if that is possible in the blheli program).
While desoldering cables from the battery pins of this ESC, I heard what sounded like a spark - first from one pin, then from the other. This occurred with an ESC that had never been connected or used. I didn’t short the pins during the desoldering process.
Has anyone else experienced something similar? I’m curious if this is a common occurrence or if I should be concerned.
Regarding BEC - had LX8015 burned. Added capacitor on the input. As of now ok.
I’m going to replace my broken one with the bigger one just to be sure.