I have an issue with the hexacopter that I can't seem to cure and I was hoping somebody here could help me out. After completing the 680pro build I test flew the hex twice without incident, each of the two flights lasting about 15-16 minutes. Landed and immediately checked all ESCs and motors for heat cause I was aware this was a good indicator for electrical issues. On my 3rd flight I got a little cocky and flew a few hundred feet out over a field, that flight resulted in an end over end crash. I wasn't sure what caused it but looking at the damage I thought perhaps the soldering failed on the board where I connected the battery leads. I ordered a power module the next day along with carbon fiber tubes to replace the two arms that broke as a result of the crash.
I rebuilt the hexacopter from the ground up to insure I had good solder joints on everything. The build went well, confidence was high at completion so I plugged her in and flew around the back yard, I thought I was ready for the field again. I balanced batteries, got the field kit together and headed out. After I plugged in my battery pack, armed the Pixhawk and began to spin up the motors, ESC under motor 5 puffed smoke and burst into flames. The fire destroyed the ESC, burnt to a crisp. I wasn't sure about the motor but I replaced it anyhow since it sits right above the ESC on the 680pro setup.
Unsure what to do I blogged for the answers. The majority of people suggested the obvious; check and make sure positive was connected to positive, negative to negative, they were. Some folks suggested I had a bad ESC so I changed that (obviously had to anyway since the old one was incinerated) along with a new motor. I wasn't really sure either was the cause, but went along with it anyway. I knew my soldering was good cause I had triple checked. Also, I had flown it in a quick back yard test flight so if the connections were wrong it would have caught fire then. I didn't believe the ESC was bad because it had flown before, never showing signs of heat. Was it the motor?
After rebuilding the hexacopter I finally was ready to test fly again. First flight I got off the ground level but had no yaw control so I set it back down after a 30 second flight and took it inside to check PIDs, etc. On my 2nd flight the yaw control was there but she went over sideways on take off so I power cycled it to reboot the Pixhawk thinking it needed to be refreshed. When I plugged the battery back in, armed, spun up the motors, I once again saw a puff of smoke from motor 5, however this time I was quick enough to unplug the battery before the whole thing went up in flames. I had plugged in the battery a few times on the bench during the rebuild, plugged it into my computer for calibration, spun motors with and without props and never felt heat from any of the electronic speed controllers or motors. Then all of a sudden dead 5s dead again in somewhat similar fashion to the first time. Now that it's back on the bench I notice that the negative lead to my battery pack is blackened, cause or result? When I plug the battery in motor 5 glitches and spins irregularly. All other motors are fine. I'm afraid to keep it plugged in for more than a few seconds because I don't want to spend another $50 on a new ESC AND motor.
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Can anyone please offer me any input as to what the root of this issue might be? I'm running a Pixhawk flight management system on the 680pro with Multistar Elite 4006 740kv, Turnigy Plush 30A ESC and a NanoTech 4s 6000mah LiPo battery.
Any and all help would be greatly appreciated!
Cheers
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