Nice! I would be a little spooked if one of mine suddenly cut power. Did you find the problem? That was a nasty crash!
My best guess is it was a bad motor. There's a chance some debris got in there and took the insulation off of the windings which caused them to Arc. Never know for sure.
Watched your last video. That motor looked bad! I would send those motors back to the manufacturer. It looks like the windings got too hot, expanded until they touched and fused together. There is not much room between those windings. When copper gets too hot it will expand exponentially. The only fix I can think of is using MG Chemicals epoxy coating in between all the windings to prevent them from touching or allowing any dust from getting in.
That makes total sense. Both failures happened towards the end of their flights, about 15 minutes in. Last two fights after the repair, I have taking their temperatures with a handheld device. The readings have been all within about 5 degrees of each other in the high 70s to low 80s which is resemble, so who knows.
Where those windings are so close together, they could be ionizing the air between them. That burnt motor fused it's windings by overheating or ionization. A burnt disconnect plug on the motor lead would raise some red flags that something is not normal. Those banana plugs are big and should be able to handle any Lipo load. The epoxy coating is the only thing I can think of if you use those motors and seal off between the windings completely. You do have a real head scratcher. The largest I fly is a 250 and lower. I don't have much of a desire for anything bigger for now.
That burnt banana plug was on a different motor. Only a small portion of it was making contact with the female counterpart. It was a factory banana plug. the one I put on is built differently. It is an after-market job. All of these parts on the Iron Man 650 were off of a quadcopter frame I custom built from scratch that turned off at about 200 ft luckily, it landed on it's landing gear and there was minimal damage on the deck, almost none miraculously.
That is amazing how it landed from 200 feet! I have only had one crash where I had a landing on the legs but it was just a few feet off the ground. I lost control while flying too close to a parked vehicle. Back when I was learning to fly I crashed every time I flew but with a fan induction mini quad. I feel for you. You invested a lot of time and money into your 650 Tarot Ironman to have motor issues knocking it out of the sky. I know I will be paying more attention to my motors from your post here.
