(19-Mar-2023, 10:33 PM)EyeBotXander Wrote: Update to this problem: I am going to go out on a limb and call the issue SOLVED. I put in a new FC, specifically, the Speedybee F405 V3, and without changing anything else at all, the quad is awesome. I setup Betaflight 4.3.1 (because that is what it shipped with), and ran it on default PIDs and filters, and left the ESC settings, left the same motors, etc, etc, and now it is SMOOTH as butter, handles great, no death rolls (at least not after 5 packs). Feeling really great about where it is at right now. It was very windy today (steady wind >20mph, with gusts of 30), so no proximity or fancy stuff, but it was clear enough to test it out pretty well, try punching out, diving, cruising, racing, etc. No power issues, no wobble, only wonderfulness.

Only issue is the vtx, which is now wired through the FC instead of direct to vbat, and it is now not as good as it was before. Nothing else has changed. It was super solid before and I could fly the whole field on 400W, behind trees and bushes, but now I can't make it to the end of the field without breakup unless I go to 800W, so I have some investigating to do, (in addition to PID tuning later), but at least it is flying nice now. I am happy. The quad is better off now. That old F3 FC has been decommissioned.

Thank you everyone for your help!

Thank you for taking the time to document your experiences. I am having the same problem on my 5in quad build. I have been flying the drone for several months, and recently I encountered the infamous death dive. The motors continued to spin after the crash and I could not disarm the quad. It was a horrifying experience. The sound of the quad was terrible. I was flying low throttle in a straight line about 5 feet from the ground. Nothing out of the ordinary. I re-soldered a broken motor wire from the crash and tried to fly the quad again yesterday. I flew line of sight in case the problem occurred again. After about 5 seconds hovering the quad, the death dive began. The drone started flipping, crashed into the ground, and I was not able to disarm the drone. I had to step on the drone to break the props off to unplug the battery. The drone smelled extremely hot, and I will most likely need to replace the motors. I am most concerned about the quad not disarming. While the drone is armed, without props on, I am able to arm and disarm the drone. I read this thread and came to the conclusion that replacing the flight controller is the best solution. Based on the information I provided, do you agree this is a good idea? Do you have any idea why this issue would be caused?

This is my first posting on IntoFPV! Thanks for being so helpful everyone.