DJI F450 - Naza V2 GPS - Noob question

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sonic393

Member
I installed and configured the F450 according to all of the tutorials available online (web/youtube) and I am sure I didn't make any errors. Now since I didn't make my maiden flight yet, I wanted to hear from some pro's what the correct steps are to do your first flight.

I do have a strange thing that I wanted to ask.

I put my F450 down on the ground, activate my transmitter first (Futaba T8J) and then connect the power to the F450. I've read the best way to start is to go with Atti mode, so I flick the switch to Atti mode. I then power on the motors by holding the 2 sticks together, no problems there...

But then, still in Atti mode, when I move my throttle stick upwards, nothing happens until i get to about center and the motors start spinning very fast, yet not fast enough to lift it. This seems very strange behaviour to me, because when the quad is in the air, to lower it, you need to lower the power to a little below mid (I think?) but when I do this still on the ground, the motors just jump to idle. If this would be happening in mid-air, it would just drop out of the sky I assume...

When I then flick the switch to manual mode, the throttle stick acts normally, I can ease in the throttle like it's supposed to act. At this point I'm not willing to make the first flight until someone can clear this behaviour up.

Could this behaviour be some GPS error, or that I don't have enough GPS signals or...

In the Naza assistant software, all stick calibration is done and working like it should. GPS calibration is also done, IOC also works when I flick the switch, the failsafe is also set radio & software)

Any help would be much appreciated!
 

Benjamin Kenobi

Benjamin Kenobi

Easy? You call that easy?
Hey mate,

All normal! The motors only reach idle speed under 50% throttle in ATTI and GPS. It's a safety feature to stop you flipping on the ground if you give stick inputs. All will be well in flight! :tennis:
 

S

sonic393

Member
So to do my first flight, I set it to Atti mode, move the throttle up to the point where the motors start spinning fast, and then slowly add more power until it lifts of?

Again, sorry for these beginner questions, but it's better to ask twice than to crash once :) This equipment is far out of the "toy price range" :)
 

Benjamin Kenobi

Benjamin Kenobi

Easy? You call that easy?
No need to apologise! I needed new underwear after my first flight!

Yes, you've got it, slowly increase throttle above 50% and it should take off. I personally use GPS mode, it works really well and is pretty impressive.

You sure the controls move the correct way in the assistant program?............just checking!
 

S

sonic393

Member
Benjamin Kenobi said:
No need to apologise! I needed new underwear after my first flight!
Click to expand...

Ok I will have a fresh pair lying around :)


Benjamin Kenobi said:
You sure the controls move the correct way in the assistant program?............just checking!
Click to expand...

Yes, All controls have been checked multiple times, to the point of having OCD :) Compared the movements of the sticks to what it's supposed to do on youtube videos, so I'm rather sure I did that part correct. But yes, better to check now :)

Another question: three red blinks (inside the house) makes me assume when I view at the "led code chart" that I don't have enough GPS signal? What color scheme should the led have when it's safe to start flying? (outside of course)
 

Benjamin Kenobi

Benjamin Kenobi

Easy? You call that easy?
Yeah, expect three flashing red LEDs inside. Outside wait for the red to go away, you'll need to be in a reasonably open place. Do the compass calibration once the RED LEDs have stopped. Then you're ready to go!
 



S

sonic393

Member
Benjamin Kenobi said:
Let us know how the flight goes!
Click to expand...

I will :) Is there a special switch on my radio to make it stop raining outside so I can go fly? :) It always raining when you don't want it to...

Another question: Is it better for me as a beginner to start with the default props, I currently mounted Graupner 9 * 5 E-props.. I've read they are much better than the stock ones, so I installed them allready...
 

Benjamin Kenobi

Benjamin Kenobi

Easy? You call that easy?
I use the Graupner 9x5 also. Great props and smooth. Why not just start with the best eh? They feel very brittle so probably won't survive a crash too well, so just don't crash. There's no reason to crash on these GPS rigs.

Good luck!
 

S

sonic393

Member
Another question, regarding the question that started this post... Is there some kind of info about this new behaviour in a DJI manual of some sorts? I can't seem to find any more info about this, or I'm no good at finding things :)
 

Benjamin Kenobi

Benjamin Kenobi

Easy? You call that easy?
I can't see it in the manual either but when some new firmware came out last summer a number of people mentioned it.
 

S

sonic393

Member
Dit my first flight this evening.. agian had to wait for the rain to stop...

Only tried atti mode for now, but had good GPS reception (no red light) so it wouldn't be a problem, but hey, baby steps :)


It's going to take some getting used to, most of all knowing when the front of the quad is pointing towards you, that you need to reverse the movements (or switch to home/course lock, but I thought that only worked in GPS mode)

I do have a question for users (or anybody really) with a similar setup a mine (F450 with 9*5 graupners and a 3S 3300mah Gens ace) what the best gain settings are. Is it "dangerous" to set the gain values trough the X1 knob and slowly adjust them in flight, or is it better to change them in the assistant, test and then change them again and so on...

Maybe somebody allready did this test and has some good starting values? The quad did look rather stable but did float (a bit) in all directions, maybe this is because i only tried atti mode?

I do also have the 4 landing legs available, but did not attach them yet. Do i need to recalibrate anything after attaching them or has this nothing to do with some center of gravity change?



A lot of questions....


PS: did not need a fresh pair of pants, but it came close :nevreness:
 

Benjamin Kenobi

Benjamin Kenobi

Easy? You call that easy?
It's fine to start adjusting gains with the knob. That's how I did it in the beginning. Adjust until you are happy with how it performs. Start at 100% and work your way up. Just remember not to adjust the knob again until you have looked in the assistant and can see how much you've adjusted it by for the next time.
 

S

sonic393

Member
Did a battery test flight today (more than one of course :) )

To be exact so others can compare:

- Stock DJI F450 with naza m V2 & gps
- zenmuse control unit installed (nothing else, no gimbal mount or gimbal) I allready added the control unit because it had to be soldered on.
- Graupner 9*5 props
- Futaba 8 channel reciever (traditional connections, not sbus)

Weight: 833 grams

- Gens Ace 3S 3300 mah battery, advertised as being 297 grams, but weighs 284grams.

Weight total : 1118 grams


Flight time with a fully charged battery: 13.5 minutes. I flew until the red light starts blinking, landed immediately and connected the battery to the charger to check battery volage: 11,1 (devided by 3 gives exactly 3,7 wich is perfect according to the all famous 80% rule...

Recharged the battery and put 3205mah(I think, I'm not exactly sure of that number but it's really close to that) back in... I'm hoping to get a 4S 4000mah or something in that region, maybe a 4S 3300mah to compare how a 3S does against a 4S with same mah...

When my money has grown back on my tree in the garden, I will buy myself a gopro.

Weight of the gopro is about 74 grams, tha gimbal with all the attachments is around 150 grams, dji landing gear around 70 grams (I spraypainted them black, looks far better to me but adds a couple of grams weight).

So with gopro/gimbal mounted this will be around 1420 grams give or take... Normally enough room to spare for a video downlink...
 
Last edited by a moderator:

Benjamin Kenobi

Benjamin Kenobi

Easy? You call that easy?
Hey mate, just saw your reply pop up.

Important! 80% rule is 80% of the mah of the pack. If you're using a 3300mah pack and put back in 3205mah then you took that lipo down to 3%! You should put back in 2640mah for 80%.

Also, don't rely on the red flashing light (low voltage warning). Instead, fly for say 5 minutes and see how many mah you put back in. Slowly increase your flight times till you are putting back in 2600mah, that's your maximum flight time. Forward flight uses more power than hovering, naturally. I have my timer set so I have at least one minute to get home and land.

Cool?
 

S

sonic393

Member
But all of the times, when I landed i had at least 3,5v / 3,7v in each cell left (cold) , so that's good right? Or does the voltage / mah have nothing to do with each other?

As I said I wasn't sure any more about the amount I put back in, I will check it again next flight :)
 




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