Naza Lite - could intelligent cut-off mode kill the motors in air when descending?

[JacobGH]

I've got a DJI F450 with a Naza M Lite controller. The controller is currently set in "Intelligent" cut off mode, meaning that, when landed, you can shut off the motors by pushing the throttle below 10% and then waiting three seconds. I just wanted to know if the same behavior would happen in the air? Let's say I send the machine way up high, then I decided to descend quickly by dropping the throttle to zero. If I do that for three seconds, will the motors shut off mid air, thus sending my quad tumbling, uncontrollably to the ground? Or does it know that it's not on the ground because of the altimeter and keep the motors idling and waiting for me to turn up the power again?

If this dangerous situation can, indeed, happen, then how do I avoid it? Would switching to "immediately" cut off mode in the Naza Assistant prevent this from happening?

 

[FlyGirl]

True but 3 seconds is a long time if you accidentally drop below 10% and even if they did stop midair you have 5 seconds to restart them by simply going back above 10%.

 

[Benjamin Kenobi]

I've got a DJI F450 with a Naza M Lite controller. The controller is currently set in "Intelligent" cut off mode, meaning that, when landed, you can shut off the motors by pushing the throttle below 10% and then waiting three seconds. I just wanted to know if the same behavior would happen in the air? Let's say I send the machine way up high, then I decided to descend quickly by dropping the throttle to zero. If I do that for three seconds, will the motors shut off mid air, thus sending my quad tumbling, uncontrollably to the ground? Or does it know that it's not on the ground because of the altimeter and keep the motors idling and waiting for me to turn up the power again?

If this dangerous situation can, indeed, happen, then how do I avoid it? Would switching to "immediately" cut off mode in the Naza Assistant prevent this from happening?

Yes, it could happen. If you set it to immediate then you wouldn't have the three seconds at all, it would instantly drop! All you have to do is not drop the throttle below 10%, simples. :nevreness:

I have mine set to immediate for safety reasons, if it crashes I want to be able to kill the throttle quickly and easily without having to do a CSC.

 

[RobBurn]

I've got a DJI F450 with a Naza M Lite controller. The controller is currently set in "Intelligent" cut off mode, meaning that, when landed, you can shut off the motors by pushing the throttle below 10% and then waiting three seconds. I just wanted to know if the same behavior would happen in the air? Let's say I send the machine way up high, then I decided to descend quickly by dropping the throttle to zero. If I do that for three seconds, will the motors shut off mid air, thus sending my quad tumbling, uncontrollably to the ground? Or does it know that it's not on the ground because of the altimeter and keep the motors idling and waiting for me to turn up the power again?

If this dangerous situation can, indeed, happen, then how do I avoid it? Would switching to "immediately" cut off mode in the Naza Assistant prevent this from happening?

you will find out quickly that you will never want to descend that fast, i think 1-2m/s is my limit, ive done 3m/s and it can begin to wobble a bit (depends on wind) and its not comfortable to me and that is id guess 30% throttle. The only reason i can see trying to descend so quickly is your pushing your battery limit and "dang" i need to land!

 

[JacobGH]

Alright. I'll just be careful. I've definitely dropped the throttle to zero for a second or two before, and then pushed it back up to make sure the motors don't die on me. I end up doing this weird pulsing motion where I repeatedly push it down...pause...then up...down...pause...then up... to avoid staying in the cutoff zone.

 

[darwin-t]

 

[darwin-t]

If it is airborne, holding the throttle will NOT shut off motors if intelligent motor cutoff is used. I have held the throttle at zero for extended periods when bringing my FC40 (which uses a different version of NAZA, but they work the same way) from high altitudes.

 

[RobBurn]

If it is airborne, holding the throttle will NOT shut off motors if intelligent motor cutoff is used. I have held the throttle at zero for extended periods when bringing my FC40 (which uses a different version of NAZA, but they work the same way) from high altitudes.

I think one needs to be careful because i think depending on the MR and weight with zero throttle you can lose stability quickly and easily trip the 70 degree angle to shut off the motors.

My question to you is you mention you do this with your fc40, does this have a camera setup? You must have this perfectly balanced to basically perform a freefall at zero throttle?

I ask because i have a hex that is loaded just under the allowance and if i hit 3 m/s coming down it is not stable imho and im not at 10% or under throttle. i can imagine a gust of wind hitting it while its in a basic free fall and it tilts or flips and its over.

 

[darwin-t]

After thinking this over, I believe that I have NOT held zero throttle except once. One time my FC40 auto landed and I know the low battery alarm had not triggered. It landed in tall weeds and it took me 2 hours to find it. I should have Flytrex data and video from it, if I can find it.

As for balance, the FC40 has the camera in the front, well away from the center of gravity. Many people end up putting a GoPro or even a gimbal with a GoPro up there. This puts the quad seriously out of balance, but other than it moving forward when taking off, it doesn't seem to make much difference.

I don't do a freefall! I was saying that I thought I cut the throttle all of the way down to descend quickly. I honestly don't know if I do that or not, other than the one time it auto landed.

I move laterally at full speed as I descend, too, to avoid the prop wash. I seldom come straight down