F-550 Naza + GPS Rapid Uncontrolled Ascent

b0nafide

Member
The Setup:

Stock DJI F-550 w/ Naza + GPS
10" DJI 1045 Props
3S, 3800 mAh, 50C continuos output battery
Turnigy 9XR
FrSky DJT Combo (V8FR-II Rx)
... No gimbal, no legs, no camera, no nothing else. (I'm not adding anything until I learn how to fly)

Gains: all at 100% (Default)

I have tested and re-tested all of my flight modes, failsafes and voltage settings in the Assistant software - everything is working as it should. I have further calibrated the compass and observed each of the failsafe work in my house while weighing the Hexa down.

I have flown my Hexa three times now and here is the result:

Flight one:
In my garage (15 ft ceilings)...Attitude mode... I attempted to get it to hover but once I began to hover the Hexa shot up to the ceiling and crashed down. ****ty deal - my bad. Probably shouldn't even try to fly it in an enclosed space.

Flight two:
Out in a field near my house. I powered everything on... placed the Hexa into Attitude mode then began to very slowly increase the throttle. Once I got the throttle to about 40% the Hexa shot up like a rocket. It went so high in the sky that I couldn't even see it. I have no idea how/why it went so high. I checked my remote and still my throttle was just above the center point (50%). I obviously lowered it to about 10% while I looked in the sky. It was seriously gone... I thought holy ****. This didn't just happen to me. I didn't just spend $1000 to watch this thing disappear into the sky! I engaged the failsafe switch and hoped for the best.
As I danced around in desperation, I kept looking to the sky. Eventually, I caught a view of my Hexa descending at a very slow rate. Even so often it would wobble a bit but I understand that this is normal behaviour when descending rapidly. Once it got low enough that I could figure out which way it was pointed, I disengaged the failsafe and lowered it down. Unfortunately it wasn't the smoothest landing (I broke the leg under motor #5) but I was just happy to see the Hexa again.

I took it home and tinkered with the settings.. I reconfirmed all of my flight modes, checked the throttle to make sure that it moved slowly and triple checked my failsafes again.

Flight three:
Prior to taking off, I attached a voltage sensor set at 3.8v per cell. I took off in GPS Mode very very slowly and actually got the Hexa to hover (it didn't take off until throttle was about 50%). I started rotating it and actually felt like I was in control then suddenly once it hit about 15 feet altitude.... ZIIIIIIP... up it goes again. As it was ascending, I could hear my voltage sensor beeping. It didn't go quiet as high as flight one but it was uncomfortably high enough for me. Once again, I'm starting to panic on the ground... I had no control over the Hexa. I couldn't move it forward or back and it didn't respond to any of my stick movements. I flicked it into failsafe and it started to drift away from my postion a bit. Then it began to decent very slowly. I flicked off the failsafe and tried to take control but no luck. It would not respond to my sticks. At this point, I think it was in voltage protection mode (set to auto land). Once it was on the ground, I practically bear hugged it because once again I thought it was a goner. The timer on my remote read 5:02 and all of my cells on my battery read 3.8v.

Note: All of my batteries were fully charged. Flights two and three were at 5:00pm (about an hour before sunset here) with mild wind. The temp is about +3-6C and it was a clear sky.



I'm a little bit lost being a newbie and I would sure appreciate any help you all could provide. I am loving this hobby but I'm both scared and giddy each time I put this thing in the air. Someone please help me figure this out!
 
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b0nafide

Member
I just did some bench testing of this issue by weighing down my Hexa and slowly raising the throttle.

Once the throttle reaches 55% the Motors increase in throttle speed by ten fold. They go from a low hum to a rapid Wooosh.

For reference, I've attached a Youtube demonstrating this:




Any ideas?

My Radio settings can be found here
 
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gtranquilla

RadioActive
1) Get it back to the bench and thoroughly prove all functions thru Naza Assistant and recalibrate. That program is a life saver for verifying your MR is responding to RC transmitter commands correctly without full on flight verification. And don't forget to complete the compass calibration etc.

2) Attitude mode attempts to manage your altitude for you by means of the onboard altimeter/barometer. But you can still override that with manual throttle control. And if you mess with yaw control while flying you will inadvertently bump your throttle up or down with very dramatic results!!!!
In any case Yaw trim is usually close to where it needs to be if you calibrated your joysticks on the bench with NAZA assistant correctly.

It is so much easier to fly once you get pitch and roll trimmed and get hovering under control. Then you can fine tune yaw..... then switch to GPS mode to lock it's 3D position down to one spot in the sky.

I spent many hours flying a Blade MQX before jumping to the F550 Naza.
Also I have a trainer box that I can connect to my RC transmitter which enables me to train others..... makes it very simple for learning. You should seek local assistance for learning. There are many MR flyers will to help new flyers and even the easy to fly F550 is a handful for a beginner!
 

b0nafide

Member
I'm confident that every function works like it should. The throttle is smooth in the Naza Assistant and there is no obvious reason why this sudden jump in throttle is occurring.

This has nothing to do with me being a rookie flyer - there is something fundamentally wrong here with either the programming, the Rx, or the Naza itself. I am not conducting any yaw or rolls while it is sitting on the ground as demonstrated in the video. This is exactly what happens when I fly... I get it to about 50% throttle and then boom! It's up 100 feet in the air for no good reason.
 

quad flyer

Member
From what you describe it sounds like there is an issue with the barometer in the naza which is used to control the altitude in both GPS & atti modes. in those two modes the throttle setting at 50% should give neutral altitude, i.e. maintain hight, throttle below 50% will decrease hight, above 50% will increase hight, this is different to normal or manual use of the throttle.
I would suggest trying manual mode to see if you have the same "motor run-away", if it fly's ok, it would point to the barometer.
You may have already read about how direct sunlight on the left-hand side of the naza can disrupt the barometer and can cause a very similar altitude fly-away. Some black tape on the side of the naza usually resolves that issue.
I hope this helps you find out what's causing the problems and you get flying again soon.
 


gtranquilla

RadioActive
The manual indicates that the maximum ascent rate while in Attitude or GPS mode is restricted to 6 meters per second..... if you perceive that it is climbing at a more rapid rate then you know that the Naza is not achieving GPS or Attitude mode but is operating in Manual mode. And in manual mode it can climb at a breakneck speed!

I'm confident that every function works like it should. The throttle is smooth in the Naza Assistant and there is no obvious reason why this sudden jump in throttle is occurring.

This has nothing to do with me being a rookie flyer - there is something fundamentally wrong here with either the programming, the Rx, or the Naza itself. I am not conducting any yaw or rolls while it is sitting on the ground as demonstrated in the video. This is exactly what happens when I fly... I get it to about 50% throttle and then boom! It's up 100 feet in the air for no good reason.
 


b0nafide

Member
I checked it in all modes. In GPS & Attitude Mode it does the run away thing. In manual mode it is smooth as butter - weird.

I don't think a little bit of tape is going to make a lick of difference when flying indoors.

Exp on the remote means: "Trim Inc: Trim Increments" which is set to "Exponential" (1 of 5 different selections). There has been no trim inputted.

I checked the curves - nothing.

I went into a diagnostics screen today and watched the throttle go from -100 to 100. This is identical to the way all of the other sticks work. There is no sudden jump which has now been proven in the manual mode. Again, I've further confirmed this in the Naza Assistant.

I further created a new model in my remote and only made adjustments to the first 4 channels (R, A, T, E)... tried to fly it in Atti mode, same thing.

I'm a little bit stumped here. If it wasn't for the GPS and my Failsafes, I would have had a fly-away during my first flight.
 

Ttelmah

Member
Have you considered that you may be getting radio interference when the power reaches a certain level?.
If this happens and the failsafe is correctly programmed, the copter will climb to about 65', as part of the RTH programming.
A problem with a BEC causing the receiver supply to go intermittent, or RF noise.

Best Wishes
 

OneStopRC

Dirty Little Hucker
I think your gains are too low,

Try 160, 160, 150, 160, 130, 130.

See how that works out. Please remember, these numbers are NOT my numbers but pulled from another unit with similar specs to yours. I do not take responsibility for any damages as a result from you trying these numbers.

But your gains are probably way too low to mean much to the Naza, and when you're at 50%, the Naza is trying to hover, then you crack it a little more and off she goes.

If all goes pair shaped, hit your fail-safe and let it land itself.

Now I take it you're flying in Atti or GPS right? You will find (if you try it) in Manual mode, these issues will go away.
 

quad flyer

Member
Since it fly's ok in manual mode but does the "fly-away" thing in atti & GPS mode, it would suggest the general setup & setting are ok (fine tuning of the gains excluded) and would point to a problem / issue with the barometer.
Try deanot's suggestion of increasing the gains to see if this improves things.
 

gtranquilla

RadioActive
Normal behaviour for the motors is to accelerate rapidly when your MR is tied down like that and the throttle is raised above 50%. Why? Because your throttle PI loop is anticipating an increase in altitude and when an increase it altitude does not occur, the PI requires the throttle to increase rapidly in a desperate attempt to get to where it is supposed to be which will never happen under these conditions.

Once again..... I remain convinced that your RC system is not configured correctly!!


I just did some bench testing of this issue by weighing down my Hexa and slowly raising the throttle.

Once the throttle reaches 55% the Motors increase in throttle speed by ten fold. They go from a low hum to a rapid Wooosh.

For reference, I've attached a Youtube demonstrating this:




Any ideas?

My Radio settings can be found here
 
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OneStopRC

Dirty Little Hucker
Just watching the video, I can tell you also, that is normal behavior. The reason as stated above, it does that because it is seeing no lift. Do the same without Atti or GPS mode and it will not do it.

Adjust your gains, take it outside and try again, with nothing on it this time.
 

b0nafide

Member
Guys, I see what your saying about the RC not being configured correctly. I agree... there has to be something not right in my control. I'm going to post on the remote's forums and see if someone can help me troubleshoot.

In the meantime... I don't think this is normal behavior. If my Hexa didn't rapidly shoot up 400+ feet in the air upon 50% throttle I'd agree with you but whether I have it weighed down inside or not. Its doing this same thing.

Also... a motor and an ESC burning up last night. So I'm down for the count right now.

I really appreciate all of the troubleshooting suggestions and help. Thanks and keep em coming!
 

OneStopRC

Dirty Little Hucker
Guys, I see what your saying about the RC not being configured correctly. I agree... there has to be something not right in my control. I'm going to post on the remote's forums and see if someone can help me troubleshoot.

In the meantime... I don't think this is normal behavior. If my Hexa didn't rapidly shoot up 400+ feet in the air upon 50% throttle I'd agree with you but whether I have it weighed down inside or not. Its doing this same thing.

Also... a motor and an ESC burning up last night. So I'm down for the count right now.

I really appreciate all of the troubleshooting suggestions and help. Thanks and keep em coming!

You have too much weight sitting on the 550, you need to adjust your gains.
 
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b0nafide

Member
Well guys.. it had to be a problem with my mixes.

I deleted all of my mixes and re-checked my wiring. I made all of my mixes from scratch (just empty channels to start with, no defaults).

I re-programmed it, bench tested it and everything seems to be in order. Although, I only bench tested without props there was no increase in the motor sound. So I think it is good to go. The problem had to be in my mixes...

I'll conduct a post analysis of it later once I get some time to see where the conflict was. I wrote all of my previous mixes down.


Anyways.. my new motor and ESC will be coming early this week. In the meantime, I'll make a video or two to demo had to properly setup my remote (Turnigy 9XR) to this Hexa.
 
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b0nafide

Member
Ugh... I'm not convinced that it's fixed.

What I have noticed is that once my throttle hits 55% or so.. it sounds like the motors goto their absolute max at that point. If I increase the throttle stick up (between 60% to 100%) there is no difference in the sound. So it basically hits 55% then automatically goes to 100%? This doesn't seem right. I get that the barometer isn't sensing any altitude gain so it increases the throttle even more to compensate.

Hum... can someone take the props off their Naza setup and do the same. See if it does the same thing in Atti and GPS?
 

tstrike

pendejo grande
I just tried it in atti on a hex and once it gets to about 55% there is no more ramping up of speed. It's a long shot but when you calibrated your sticks in naza assist, did you finish with your throttle arrow in the middle and green?
 

gtranquilla

RadioActive
Oh Brother Where Art Though!
I do not have the same type of RC system as yours so can't help you if there is a radio configuration issue. As far as the MR is concerned here is what I know.

My MR will smoothly go between 0 and 100% throttle when it is tied down and configured for manual mode and it will go from hover to 100% throttle instantly when I flip the RTH switch on. Can't tell you what happens in Attitude and GPS mode until I tie it down again..... will try as soon as I get a chance but not til later packing for a flight now.

It is imperative that the "U" pointer in the diagram below show up with a blue bar directly above when you flip your GPS-Atti_Manual switch back and forth between the three positions. If it does not and/or the blue bar shows up in the Failsafe boxes you will be perpetually in failsafe mode which means your motors will scream out-of-control toward 100% throttle until you reach the 30 meter altitude as required for RTH.

View attachment 10014


Ugh... I'm not convinced that it's fixed.

What I have noticed is that once my throttle hits 55% or so.. it sounds like the motors goto their absolute max at that point. If I increase the throttle stick up (between 60% to 100%) there is no difference in the sound. So it basically hits 55% then automatically goes to 100%? This doesn't seem right. I get that the barometer isn't sensing any altitude gain so it increases the throttle even more to compensate.

Hum... can someone take the props off their Naza setup and do the same. See if it does the same thing in Atti and GPS?
 

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