Help with iFlight nazgul5 V2 death roll?

[itsniklavs]

Hey, so i just got the iflight nazgul5 v2 4S BNF quad. Set it up, tried flying it for a few seconds and it just started literally spinning and dipped mid air.
I couldnt understand what had happened so i tried googling it and looking on youtube and everything, i found out that this is called a "death roll" when the motors "desync" i guess(??)
Thank god a friend of mine was filming my first flight - mov: quad troubleshooting.mov if you zoom in super close it looks like it starts rolling mid air but i cant seem to understand which side/which motor is to blame. But when i take off the props and power it up at home, the motors seem to work perfectly fine when i increase/decrease the throttle.

Oh and a general question - should the motors\flight controller/VTX get hot when a battery has been plugged in even when its standing still for some time (5-10 min) or e.g. the motors are spinning with no propellers on?

ANY help will be greatly appreciated since im kinda new to this hobby and theres A LOT to learn Smile

p.s. if there are any settings/info i should check/post here please feel free to tell me! Trying to learn as much as i can.

Thanks!

 

[Chris_A]

I have the 6s version so I'll help the best I can. Was this the maiden flight? Have you set it up in Betaflight? You're probably going to need to show us the CLI dump (diff) file so we can see everything. That was a hard hit ol' girl took when she came down. The VTX gets hot, yes, so I generally don't keep the battery plugged in for too long when she's on the bench unless I have a fan running.

 

[itsniklavs]

I have the 6s version so I'll help the best I can. Was this the maiden flight? Have you set it up in Betaflight? You're probably going to need to show us the CLI dump (diff) file so we can see everything. That was a hard hit ol' girl took when she came down. The VTX gets hot, yes, so I generally don't keep the battery plugged in for too long when she's on the bench unless I have a fan running.

Hey, thank you for the quick response!
Yes this was the first time i tried flying it, as for setting up betaflight, i have no idea what should i be looking at specifically because i read that it has been pre set up already from the factory, of course i checked out a few settings and stuff but everything looked fine to me, since im very new to all of this i try not to mess around with anything i dont know about.

Heres the "diff all" and "dump" files - txt

As for the hit, i hope it didnt affect anything, it did look a bit bad tho, but nothing broke when i inspected it.
Thanks about the battery info, will take notes

As for the blackbox, idk if this helps, but i had never ever touched it and yesterday i just went and exported everything thats on it - bbl
It gave me 77 different flight logs, the rest of them are little 1-5 second tests of me just not knowing what i do and doing some stick movement with no propellers and on my desk so please ignore those, as for the crash that im looking for I assume its the last log on the list since that is the longest flight i have got there. But just to be sure, is there any way of telling on what date/time each log has been created? I noticed that the 8mb blackbox was full when i exported, so maybe it has never even recorder the crash. If im able to find the date/time of it i can perfectly find the one i need, since there are maybe a few like 9 or 18 second logs im really not sure which one is the right one.

If there are no options on checking the date of recording, are you able to see which flight it may have been just by looking at it + the video i have provided? Im pretty sure its the last log (29sec long), but again i dont really know since i dont understand the blackbox files and they are all just lines and curves and stuff to me

Huge thanks for everything and anything!

 

[mrmund]

Welcome to the forum.
I'm not sure if Iflight sends that quad with airmode turned on. Some manufacturers don't and you'll definitely want it activated.

 

[itsniklavs]

Welcome to the forum.
I'm not sure if Iflight sends that quad with airmode turned on. Some manufacturers don't and you'll definitely want it activated.

Hi, im not sure but i think it is already activated on as needed. How can i check if its on or off?

 

[mrmund]

In the configuration tab

 

[mrmund]

Also you will want to make sure that your arming angle is set to 180degrees so you'll be able to flip is back over if you crash

 

[Chris_A]

Welcome to the forum.
I'm not sure if Iflight sends that quad with airmode turned on. Some manufacturers don't and you'll definitely want it activated.

It's activated.

 

[itsniklavs]

In the configuration tab

I have done that, it came with that setting ON by default. But idk if it has anything to do with the crash tho

 

[mrmund]

I was thinking maybe it wasn't on and that could have contributed to the crash.
I'm watching to see what the wizards on here think happened

 

[droneguy]

This issue is a desync when the ESC has an issue talking to the motor based on noise or magnetic interference and is an issue on some quads. The ESC gets messed up and causes one of the motors to go full power or the FC asked for full power to correct the desync and you end up with a spiral of death. If you have a blackbox log you will see one motor gets full power request while the others remain normal.
The simplest solution is to reduce your startup power on your ESCs from BLHeli. Load BlHeli and connect a battery to the quad (remove props), connect the USB and hit load data. Reduce the "startup power" from 0.5 to 0.25 or my preference 0.125. The hit write setup and go fly! Your desync issue should be gone for good.

 

[droneguy]

Welcome to the forum.
I'm not sure if Iflight sends that quad with airmode turned on. Some manufacturers don't and you'll definitely want it activated.

Airmode or lack of air mode will not do this. Airmode basically allows the FC to give more authority over the PID loop at low throttle. This is necessary to perform flips and tricks when you cut the throttle and float. This is required for your stick controls to have an effect when your throttle is at idle or near idle. Normally the stick commands result in the motors slowing or speeding up from their current throttle position. It is a relative change from the current motor speed. When you are at idle, there is no "lower" relative motor speed and your sticks wouldn't work properly. Your PID lood still tries to correct effects from wind, etc. Airmode temporarily keeps the motor idle speed higher so you still have "room" for your stick inputs changes to still have an effect over the relative motor speed.

 

[Chris_A]

The simplest solution is to reduce your startup power on your ESCs from BLHeli. Load BlHeli and connect a battery to the quad (remove props), connect the USB and hit load data. Reduce the "startup power" from 0.5 to 0.25 or my preference 0.125.

He's already set at .25 but .125 might be better.

 

[droneguy]

Yes, I use 0.125 on any quad with desync issues and it usually solves the problem.

 

[droneguy]

He's already set at .25 but .125 might be better.

The Betaflight parameters for airmode start throttle are 25% but I'm talking ESC startup power. Similar but different animal. The Startup Power option changes the degree of power reduction applied. Lower setting means less power reduction increasing the sartup power and increasing the ability of the ESC to determine the RPM of the motor since the magnetic field is larger with more power. Desync issues can often be attributed to Startup Power or Rampup Power (in BlHeli 32) or Demag compensation. Since startup Power limits the acceleration of the motor by limiting the maximum PWM duty cycle allowed based on the current running RPMs, the lower the rpms then the max power that is allowed to give to the motor is reduced. Most of the time reducing Startup Power is a bandaid for a large issue however. Since this was your first flight with a BNF, I would typically rule out many crash induced scenarios. You can also increase your Demag compensation (basically error correction for bad read data) but at the cost of potentially a little power and acceleration as it's performing more error correction. As I indicated, there may be a bigger issue at hand here, but try lowering your startup power to begin with.

I know it's a bit confusing, but hopefully I sort of explained it well enough.

 

[itsniklavs]

The Betaflight parameters for airmode start throttle are 25% but I'm talking ESC startup power. Similar but different animal. The Startup Power option changes the degree of power reduction applied. Lower setting means less power reduction increasing the sartup power and increasing the ability of the ESC to determine the RPM of the motor since the magnetic field is larger with more power. Desync issues can often be attributed to Startup Power or Rampup Power (in BlHeli 32) or Demag compensation. Since startup Power limits the acceleration of the motor by limiting the maximum PWM duty cycle allowed based on the current running RPMs, the lower the rpms then the max power that is allowed to give to the motor is reduced. Most of the time reducing Startup Power is a bandaid for a large issue however. Since this was your first flight with a BNF, I would typically rule out many crash induced scenarios. You can also increase your Demag compensation (basically error correction for bad read data) but at the cost of potentially a little power and acceleration as it's performing more error correction. As I indicated, there may be a bigger issue at hand here, but try lowering your startup power to begin with.

I know it's a bit confusing, but hopefully I sort of explained it well enough.

Huge thank you! I just put it a bit lower and hopefully that never happens. As for demag, my current settings are on Low, should i try using that still or like change it if it ever keeps happening again?
Will update if necessary, thank you and everyone that made some input in this