Help - F450 Quad with PixHawk 4 fell out of sky twice - dont know why?

Andy_Craig · February 13, 2018, 5:10pm

I have flown my drone twice and both times it has seemingly fallen out of the sky. I have tried to build it as balanced as I can, has a GoPro with brushless gimbal all set up, MinimOSD, FPV and all powered by 3 Cell 25C 5000mah battery. I think the first time it crashed it was a power failsafe but this time I have no idea.

I would really appreciate some help with the log since I really dont know what it is telling apart from the fact that it failed with a crash check-1.

link to log here
https://1drv.ms/u/s!AiWzH0-wbLRDudNDn-q5LSYl159mAA

Thanks in advannce of any help.

mboland · February 13, 2018, 9:15pm

Your copter is overweight/underpowered leaving very little head room to manoeuvre.

The tuning is over reacting, although this could be due to not enough power as well tuning.

And the battery is only just hanging in there.
I notice you do not have the current sensor hooked up.

sergbokh · February 13, 2018, 9:36pm

@mboland I agree with your points, but after all - what was the exact reason to crash?
Despite the copter is extremely underpowered but it flied for some time. But then Th.O goes zero. I don’t see a reason for that:

ltmarts · February 14, 2018, 2:55am

Your voltage jumps up dramatically at the same time as the throttle goes to max, then throttle drops out. I wonder if your speed controllers are set for LIPO batt and have a battery voltage failsafe enabled? This caused me several crashes because the esc battery failsafe would kick in before the FC failsafe, causing the motors to cut in flight. Changing to NIMH disables this.