Understanding Flight Logs

New to the sport, and recently had a crash for unknown reason(s). I downloaded the logs from Mission Planner and tried to make out the logs, but having a hard time trying to understand the large amount of data.

Would anyone here be so kindly to help me understand what might have contributed to my crash. I can post the logs when requested.

Thanks in advance.



Post a log.

Perfect! Thank you so much. At work, but as soon as I get a chance to post I will.

Also basically describe the copter, and what you observed - that can make it a bit easier too.

Here’s the logs.

Its a 700mm quad copter with 15.5" props. From one second to the other it just dropped from about 8 feet. I wasn’t doing anything specific.

Thrust loss on Motor 2. Could be Motor, ESC or a broken prop.

Not sure what you are doing with the 2 notch filters, they are not configured correctly. Disable the 2nd one and set the 1st one with a Freg of 60Hz, BW at 30Hz and read up on the filter to set the throttle reference.

Thanks for reviewing the logs! After the crash, I assessed the the craft and it didn’t sustain any real damage. The battery tray did get yanked out and after reattaching, I plugged it back in and was able to arm it.

What would be the best way to test the motor and ECS? The prop on motor 2 is good shape as well.

@dkemxr Do you have any recommendations on best way to test the motor and ESC?

MissionPlanner motor test.
Turn the prop over so it’s pushing down, set the percentage and time.
Only test that motor (or one at a time).
If you get this wrong the MP motor test can be very dangerous - best to take all other props off.

What is the brand and model of ESC and motor ?

Thanks for the info testing the motors.

I have flycolor BL-32 30A ESC’s and Garrt 480KV motors.

It’s unusual for a BLHELI ESC to lose sync, so there might be a overheating or connection problem.

Check that you have these settings in the ESCs using the BLHELI32 Suite, particularly

  • Low RPM Power Protect = OFF
  • Motor Timing = Auto

You might need to use another flight controller or Arduino to set them since you dont have DSHOT set up on this Cube.

With the Cube Orange it is relatively easy to set up DSHOT using the Aux connectors and get the BLEHLI data via a serial port. This would give RPM, temperature and voltage data for each ESC.
Or use the bi-directional DSHOT firmware and just get the RPM data without sacrificing a serial port.
Let us know if you want some help.

Definitely set this

You have 2 notch filters set up too, but not configured correctly.
Change these:
(EDIT, Dave said some this already)

There’s probably more we can help with, so start a new thread for your tuning and further discussions in that regard.

@xfacta thanks for the info! Your help would be greatly appreciated with the ESC and tuning. I will start a new thread tomorrow after I make the prescribed changes.

Getting back to the motor issue, the motor # 2 is bad after testing and comparing with the others.

I found some Tmotors as a possible replacement and would like your expertise please. Do you think I can use TMotor Antigravity MN4004 KV300 and a replacement? Thinking of doing all four. I hear great things, but not sure if they will work for the size of my drone.

Thanks in advance.


Going from a 480kV motor to a 300kV motor with the same prop may not work. Plug everything into eCalc and see. It’s the best Insurance against “shit, I bought the wrong motors” :slight_smile: And like everything T-Motor they are expensive.

Gotcha! Is the rule of thumb, lower KV bigger the prop.? I will have to plug in the spec when I get home.

TMotors and not cheap for sure, but I feel I went cheap and got motor #2 go bad after a handful of flights.

Yes, generally. But it’s really a combination with Battery power, prop size and weight.

Do you have any motor brand you recommend?

Getting a bit of topic here.

Perhaps best to start a new thread.
(I guess you will get various answers to that question as it depends on various factors, I.e.: cost, efficiency, power requirements, size,…)