I've got a scratch built tricopter controlled my an APM 2.6. Until yesterday it was flying splendidly.
Yesterday started behavior that I can't sort out. The tricopter will lift off as expected in stabilize mode and begin to fly normally. Then, after several seconds, it'll pitch or roll wildly and shoot off in any direction while spinning wildly.
During this time I have no control over pitch, roll, or even throttle. Oddly, however, yaw works fine.
The only way to get the thing back to ground again is to flip to RTL mode then back into stabilize. This gives me about enough control to crash before any damage can be done to people or property.
I've reflashed the firmware, tested motors and speed controls and can't sort this issue out. If the problem was compass related I wouldn't think it would present itself in stabilize mode. The compass/nav receiver are mounted up and away from anything and I have no problem with 3D lock or compass heading.
I'm at a loss here. Any help is appreciated
What's interesting is that plugging it into mission planner in my house throw no GPS errors at all. Logs from my back yard are similar. I wonder what it is about the location of the bad flights that caused that.
Either way, I've now got two motors with bad bearings after the last crash, so new ones are on order. Once I'm mechanically sound again, I'll try flying again in a different area and see what happens.