Naze32 Cleanflight Crashing Three Minutes Into Flight

luketheduke

New member
Most modern ESCs will detect low voltage or voltage sag and cut power to the motors. It looks exactly like what I am seeing in this video. Modern ESCs sense the voltage drop and they bring the copter down "gently".

When testing my new Alien I was using old 4S 30C lipos. They were voltage sagging in seconds as the copter drew more current than the old 30C lipos could provide. It looked EXACTLY like your video. After a minute or two the copter would just sink to the ground and no increase in throttle would make a difference. Testing the lipo after showed a solid 4v + per cell.

Under load the voltage was dropping close to 3v per cell but after the motors shut down the lipo showed 4v per cell. The ESCs were detecting low voltage under load and bringing the copter down.

I suspect your issue is one of available current. 20A is not much power. I think your ESCs are detecting voltage drop due to current restrictions and setting you down gently to save the lipo the ESCs think they are connected to.

The power supply I am using has a built in ammeter, and when I fly, it registers always less than 10A nominally 5A. When running with a 3S 2200mah LIPO I still get the same problem. It may be due to PIDs so I have tunedit as best I can and will try more hovering soon. Thanks for all the help so far!
 

luketheduke

New member
Is it possible that the reason for the weird behavior is an ESC sync issue? In the wiring that came with my Naze32 Acro knockoff from EMAX, ground is only connected to one of the ESCs. Does anybody know if the ESCs in the FT power packs are opto isolated? That seems that it could be causing the problem, but correct me if I'm wrong as I'm just a lowly noob...
 

Snarls

Gravity Tester
Mentor
Is it possible that the reason for the weird behavior is an ESC sync issue? In the wiring that came with my Naze32 Acro knockoff from EMAX, ground is only connected to one of the ESCs. Does anybody know if the ESCs in the FT power packs are opto isolated? That seems that it could be causing the problem, but correct me if I'm wrong as I'm just a lowly noob...

I'm pretty sure it is not a sync issue because you would hear it right away, not later in flight. Look at your ESCs and see if they all have BECs, that is they all have the three wire servo lead coming out from them. You only want one BEC from one ESC to be connected to the flight controller, and this is the one this one that gets the ground. The other three ESCs you should only plug in the signal (yellow/white) wire into the flight controller. They don't need ground. So if you have all four BECs plugged in that could pose a problem.
 

luketheduke

New member
I tried flashing the board with Baseflight, and I still get the same error, except it only decreases the throttle, it doesn't affect the pitch/roll. Any ideas as to what could cause this?
 

pressalltheknobs

Posted a thousand or more times
It sounds like a failsafe is kicking in. There are several failsafe mechanisms that could kick in.

The RX. If this looses RF connection it will do something which depends on the RX you have. Default is often "hold" which will apparently do nothing. However on some Rxs it's no signal or, no signal on throttle and on others it is a programmed setting. Better Rx's let you choose.

The FC. Depending on the firmware and board, this can be set up to detect no pulses or a continuous low programmed setting and will de-power the motors (see https://github.com/cleanflight/cleanflight/blob/v1.11.0/docs/Rx.md)

The ESCs If these lose signal from the flight controller - generally no-pulses - then they can soft cut. They might be programmable for other options. (see http://abc-rc.pl/templates/images/files/995/1424029485-emax-blheli.pdf)

Another ESC failsafe like feature is thermal protection that can limit the motor power by some percentage or maximum.

So it's odd that this happens at around 3 minutes in but I can only guess that 3 mins is the time it takes for something to warm up to failing point that that is causing a failsafe to kick in.

Since it seems all motors de-power this would seem to point to the FC failsafe but it could be being triggered by the RX failsafe.

Another possibility is the FC loses power or resets and the ESCs all stop getting signals a the same time.

You could try changing the behavior of the failsafe on the FC and possibly that will indicate something. If you RX has a number of failsafe modes you could try different ones. If you haven't reflashed them according to the Emax manual, the default Emax blheli ESCs softcut when they lose signal. I haven't found the option in blheli so it may be different if you have re-flashed them.

Anyway...some thoughts to consider. Maybe helpful.
 

luketheduke

New member
It sounds like a failsafe is kicking in. There are several failsafe mechanisms that could kick in.

The RX. If this looses RF connection it will do something which depends on the RX you have. Default is often "hold" which will apparently do nothing. However on some Rxs it's no signal or, no signal on throttle and on others it is a programmed setting. Better Rx's let you choose.

The FC. Depending on the firmware and board, this can be set up to detect no pulses or a continuous low programmed setting and will de-power the motors (see https://github.com/cleanflight/cleanflight/blob/v1.11.0/docs/Rx.md)

The ESCs If these lose signal from the flight controller - generally no-pulses - then they can soft cut. They might be programmable for other options. (see http://abc-rc.pl/templates/images/files/995/1424029485-emax-blheli.pdf)

Another ESC failsafe like feature is thermal protection that can limit the motor power by some percentage or maximum.

So it's odd that this happens at around 3 minutes in but I can only guess that 3 mins is the time it takes for something to warm up to failing point that that is causing a failsafe to kick in.

Since it seems all motors de-power this would seem to point to the FC failsafe but it could be being triggered by the RX failsafe.

Another possibility is the FC loses power or resets and the ESCs all stop getting signals a the same time.

You could try changing the behavior of the failsafe on the FC and possibly that will indicate something. If you RX has a number of failsafe modes you could try different ones. If you haven't reflashed them according to the Emax manual, the default Emax blheli ESCs softcut when they lose signal. I haven't found the option in blheli so it may be different if you have re-flashed them.

Anyway...some thoughts to consider. Maybe helpful.

That seems possible, except that after the three minutes, I still have control. I can pitch and roll all I want, just the throttle gets so low that I can't get off the ground at full throttle. Any other ideas?
 

pressalltheknobs

Posted a thousand or more times
That seems possible, except that after the three minutes, I still have control. I can pitch and roll all I want, just the throttle gets so low that I can't get off the ground at full throttle. Any other ideas?

You would still have some control if the ESCs were in thermal protection mode. Seems unlikely that all the ESCs would all do that at once though - unless maybe if they are stacked together in a contained space. Not sure if EMAX blhelis even have that feature though.

You may still have some control in a soft cut lipo cut-off by the ESCs. This seems more likely to happen to all ESCs at the same time since the ESCs are all measuring the same voltage and the circuits are probably reasonably matched.

There maybe other failsafe modes where you still have some control.

If you have the Full Naze 32 rev6 you could try the blackbox and see if it provides any clues. If you have the acro version may need to get a logger - useful anyway. I haven't tried this. Just pointing it out. Here's an article...

http://blog.oscarliang.net/setup-blackbox-cleanflight/
 

luketheduke

New member
You would still have some control if the ESCs were in thermal protection mode. Seems unlikely that all the ESCs would all do that at once though - unless maybe if they are stacked together in a contained space. Not sure if EMAX blhelis even have that feature though.

You may still have some control in a soft cut lipo cut-off by the ESCs. This seems more likely to happen to all ESCs at the same time since the ESCs are all measuring the same voltage and the circuits are probably reasonably matched.

There maybe other failsafe modes where you still have some control.

If you have the Full Naze 32 rev6 you could try the blackbox and see if it provides any clues. If you have the acro version may need to get a logger - useful anyway. I haven't tried this. Just pointing it out. Here's an article...

http://blog.oscarliang.net/setup-blackbox-cleanflight/

I was thinking about trying this next, so we'll see how it goes.
 

PsyBorg

Wake up! Time to fly!
How are your soldering skills? If the power leads to the esc and or main battery connection are not properly tinned they could have air gaps causing resistance thus shunting current and may be tricking the ESCs into low voltage cutoff. Also.. after flight what is the comparison of Mah used vs MAH charged? Is it close? I have several Flourion batteries that gave crappy flight times and even now after 25 or more flights are only up to 7 min avg times. 2 of them started at 30 to 45 second flight times before battery alarm started yappin at me.
 
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luketheduke

New member
How are your soldering skills? If the power leads to the esc and or main battery connection are not properly tinned they could have air gaps causing resistance thus shunting current and may be tricking the ESCs into low voltage cutoff. Also.. after flight what is the comparison of Mah used vs MAH charged? Is it close? I have several Flourion batteries that gave crappy flight times and even now after 25 or more flights are only up to 7 min avg times. 2 of them started at 30 to 45 second flight times before battery alarm started yappin at me.

I soldered the wires with no problems I hope. I can only assume so as I have not had a) a motor die in flight or on the ground or b) I haven't heard the arming sequence on one of the ESCs in flight. As for the battery, the issue happens both on battery and on tether. I am using a 1500Mah 3S Lipo for HK and with the battery alarm installed, I get about 5 mins of flight time hovering.

Could the symptoms I am experiencing be caused by a faulty Naze32 board? I bought the board from Amazon, so it is viable to return it, but I don't want to unless I have probable cause...
 

PsyBorg

Wake up! Time to fly!
I would think the ESC's or motors would be a more logical problem then the FC. If you can get it off the ground in a reasonably stable hover Id troubleshoot from the motors back to the FC checking everything including wire connections.

One after thought remembering the Versa build video.... They had a warning regarding the ESC to motor bullet connections and the brass being exposed causing the potential to arc.. Is it possible you have two bullets exposed that may be leaching current to the Carbon fiber tube or possibly arcing between themselves??
 

luketheduke

New member
I watched that part of the video too and as a precautionary measure, added electrical tape around all the bullet connector joints. I recorded the motor outputs while flying in horizon and will have it uploaded to YT within 24 hrs.
 

raptor pilot

Junior Member
I think I'm having the same problem. Unlike yours, mine always happens at the beginning of the flight and is intermittent, having many successful flights in between. My blackbox graph isn't showing voltage in the screenshot, but I checked the log, and it never dipped. I've been trying to get video of it, but its intermittent so no luck capturing on video so far. You can see in my graph how the motors briefly glitch, then go to zero throttle before commanded to do so.
http://forum.flitetest.com/showthread.php?25201-Motors-glitching-then-shutting-down-in-flight
 
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luketheduke

New member
raptor pilot,
Your issue seems similar and I hope you get it resolved soon, as I could potentially benefit from it as well...

On a separate note: I uploaded a video to youtube of the screen in Cleanflight Configurator while I was flying. There seems to be large spikes at the end where one motor with cut out and the opposite motor will gun. Could this be part of the problem?
https://youtu.be/uxTRy9EvMM0
 

luketheduke

New member
I purchased a new Naze32 Rev 6 from the FT store and it works like a charm. Other than PIDs, it flies fine. No crashing three minutes into flight, YAY!!!
Thanks everybody for your help!
 

luketheduke

New member
Update 6-19-16:
Since this happened, I still get the issue just intermittently. I have no clue how to remedy it. Thanks to all the people on the forum and the FT Support for all the help they have provided.
Thanks,
Luketheduke
 

PsyBorg

Wake up! Time to fly!
raptor pilot,
Your issue seems similar and I hope you get it resolved soon, as I could potentially benefit from it as well...

On a separate note: I uploaded a video to youtube of the screen in Cleanflight Configurator while I was flying. There seems to be large spikes at the end where one motor with cut out and the opposite motor will gun. Could this be part of the problem?
https://youtu.be/uxTRy9EvMM0


I didn't see anything wrong with that flight. What I think is happening in that video is you were effectively hovering in and out of ground effect over that table and depending where you got in the prop wash you got varying degrees of reaction from the gyros and accelerometers trying to keep you level. Add to that the effects of your tether putting outside forces on it as well. Couple that with weak pid strengths and that looks exactly like that flight. My runner 250 was the same way when I started flying but hovering in my living room with the prop wash bouncing off furniture and the floor.

The bigger spikes at the end I think were a combination of the tether binding and different ground effect after getting behind the monitor.
 

Darkback2

New member
How quickly does the quad recover? So for example, you fly for three minutes and it falls out of the sky... how quickly can you fly for another 3 minutes?