Servers by jDrones

Random motor behavior causes crash

I have attached the log file from a crash I experienced last week. If anyone can look at it and maybe gain some insight into what is happening I would be very grateful. (arm and crash happened between 11:45:30 and 11:45:50)

I armed the copter and spun it up without realizing anything was wrong. Once it got a few feet off the ground it suddenly flipped upside down and crashed. I have noticed reviewing the logs that motors 1,3,5 and motors 2,4,6 seems to be at very different values even though all I had done was increased the throttle. I tested this more after the crash and have noticed that if I leave the copter sitting on the ground with ~0.5 throttle, the motors initially spin at the same speed and then over time different motors speed way up and slow way down. My only question now is why is this happening?

Looking at the output spread of motors it definitely looks like a wrong motor order, direction, or props.

I would also point out you still have the default parameters which won’t be a good thing with a larger hex.
I am assuming from the 6S used that you are running something like 15” props.

Have a good read of the tuning page here and recheck you’re motors, directions, and props.

I did find out that my motor order was incorrect.

Is it safe to reorder the motor outputs in software instead of rewiring them? The only reason I ask is that the current wiring is done in two groups of 3 motors so it will take a decent amount of work to rewire.

I did not wire up this quadcopter myself, and it seems strange to me that it flew fine once and now it seems my motors are not in the correct order.

You just have to move the signal output connectors around on the carrier board. Or am I missing some difficulty with that?

So the person who wired the copter used two servo extensions (3 wires each) for the signal wires, which means they are grouped into groups of threes so I can’t individually reorder them.

Ah, I see. Sure you can re-order in firmware. I have done that on a F4 FC with a 4in1 ESC because the physical location of the solder pads didn’t line up with the motor positions as per the proper motor order. Just use Motor Test and re-arrange them.

I did this and got the copter back flying. Now just to finish with some tuning and I should be good to go!

Thanks!

Servers by jDrones