No confidence in my NAZA

[SamaraMedia]

Recently I've been experiencing a little problem when initializing my DJI F550 with NAZA controller. I have read many times about people having trouble getting all six motors to start up at the same time. Some have suggested raising the default "recommend" setting for motor start-up to a higher setting, which I've tried with mixed results, but I just have had a bad run on trying to launch my craft lately. Right now I can't seem to get all six motors to spin up together until I reach almost 1/2 throttle.

It all started after a crash while testing my PhotoHigher AV130 camera gimbal. Everything seemed fine the next time I went for a fly but then I tries using some new GemFan 11x4.5 wooden props and boosted my gains up a little to about 150, 150, 130. When I tried to takeoff the hexa began to shake violently and then one of the props spun off hitting the one next to it splintering them all up. Now I can rule out that I did not tighten all the prop nuts down but I'm almost 99% positive that was not the cause but one prop did release on it's own. since I found the nut and washer a couple days later after the snow melted.

I'm using NTM 28/36 motors, Turnigy 30A Plush ESC' with the red wire removed, Spekturm DX7S control with the AR7010 receiver, GensAce 5300mAh 4S battery (some times 2 batteries in parallel), GemFan 11x4.5 carbon/plastic props or GemFan 11x4.5 wood props. I'm using a Photohigher AV130 camera gimbal and carry a Sony HDR-CX580V video camera. Total flight weight with one battery is about 3160 kg or 3660 kg with 2 batteries.

I've attached a video showing my situation.

https://vimeo.com/57725553

Thanks for your input.

John

 

[Benjamin Kenobi]

We didn't see it fly! How does it fly? Behaviour on the ground will be odd in attitude or GPS as there's no movement to correct for and more vibration. A prop flying off is not the fault of the naza. It's pilot error (insert smiley here!).

Don't be scared of it! It's just a tool.

 

[Bowley]

Sure your ESC's are OK?

 

[SamaraMedia]

Bowley, last week I went through and re-calibrates the throttle range on each one. What I found this morning is that I mistakenly removed ALL the red wires from the ESC's so I replaced one and reconnected to the NAZA. I'm going to go through the TX re-calibration in the assistant software next. I will go through each of the ESC's to be sure they are all programmed properly.

Benjamin, maybe I will go through each of the ESC's to be sure they are all programmed properly.

Funny, after I reconnected one of the red wires on the ESC's this morning I fired it up and still had three motors not wanting to spin-up so figured what the heck and reached down to see if I could stop the motors from spinning using my finger. Sure enough, motors 1, 3 & 5 could be stopped with slight pressure placed on the barrel of the motor while motors 2, 4 & 6 were fully powered and I could not slow them down.

Just feels like something is not right so I haven't tried putting it back in the air because the last thing I need is a crash to possibly damage the AV130 or the F550. I've had it airborne before with confidence but right now I'm not so sure.

John

 

[SamaraMedia]

Just took it for a quick flight and everything seems to be normal once it gets in the air...
Changed my gains a little and will look into putting my video camera back on soon, hopefully everything works out...

John

 

[kloner]

naza has a built in bec in that light thing you plug the usb into

every one of them plush esc's has a bec in it. if it's not dissabled, your playing with shutting down an esc in flight from over heating or worse, fire. You can not run more than one bec on any circuit. they don't do well, especialy when there in the esc.

i have seen the esc behaviour your showing in the tbs simonK esc's with naza, they just suck on the ground, but once in the air they clean up

When you did throttle calibration, did you get a nice clear for sure confirmation beep? setting throttle ranges is tricky, move the stick too soon you miss it, move the stick to late, your in programing mode.

 

[SamaraMedia]

Kloner, I did get a clear confirmation beep when calibrating. As far as the bec's go, I have just one (motor one) plugged in using the red wire, all other esc's have the red wire pulled and taped back, is that correct connection?

Thanks,

john

 

[DucktileMedia]

To clarify what kloner said, cut that red wire on all your esc. Only use the naza pmu as your power to the rx. The bus is shared amongst all the pins +\-.

 

[kloner]

no red wires into the naza,,,,,, it is self powering everything from that thing with the light that flashes

 

[SamaraMedia]

That's the way I had it yesterday then for some reason I changed it to have one red wire going to the NAZA this morning. (That martini last night must have clouded my recollection of some previous thread ;0 ) I'll remove it and try again. At one time I had all the red wires connected from the esc's, some threads say it doesn't matter, some say leave just one, hard to find the right answers all the time.

Iris and kloner, thanks for clarifying setup, two of the many voices I follow here and trust!

John

 

[DucktileMedia]

To be honest I'm not sure why you can't have all of the plugged in on a non Dji controller. But since Dji has their own pmu it just makes sense to use that and take all the load off your esc' bec. But on my Hoverfly I do t know why you can't leave them all plugged up as they are not in series. Really it would seem it is a type of redundancy. Perhaps a ground loop issue? Either way I have had them all hooked up and it flew exactly the same. Hoverfly shows a picture of only 1 bec bring used yet when I asked them they said it shouldn't matter. A bunch of mixed messages with a lot of things on here.

 

[SamaraMedia]

So I removed all the red wires from the esc's as suggested and did a quick test flight. The only other change I made was put on some new GenFam 11x4.5 wood props since an earlier flight resulted in me nicking the tip of one of the props on landing when it tipped forward and spun into the pavement. The wood props replace the black carbon GenFam 11x4.5 that were on it earlier today. When I tried to lift off this time it was shaking a little on takeoff then gave a violent shake about 1 foot off the ground then settled down but still had a noticeable vibration going on so I landed it before I wasted away some more props today. The wood props weigh in at 18g while the black carbon were 13g per prop which amounts to 30g additional weight, not sure if that makes enough of a difference to change the gains or not but it sure as hell scares me when it gives that quick hard vibration. That's what happened a couple weeks back when it spit a prop off and crashed from 2 feet up and splintered three wood props which makes me leery to try getting this up higher before checking with you guys.

Anyone else experience anything similar to this when switching to wood props?

John

 

[SamaraMedia]

Today I tried something a little different. After reading many a motor spec sheet it seems the consensus is that if you use a 3s battery you can get away with a larger prop compared to using a 4s battery. I put a 3s 5000mAh on my F550 this morning and found that the violent vibration I was experiencing yesterday when trying to take off with the 4s 5300mAh battery was gone. Unfortunately what I also found is that the 3s doesn't have the balls to lift this craft off the ground effectively. End result, splintered two more 11x4 GemFan wood props when I landed and it pitched forward as I was disarming the motors.

At one point I felt I was taking one step forward and two steps back when trying to get these wood props to work but now I'm beginning to wonder how badly mismatched my motors, NTM 26-36 750kv, are with my prop and power choices. I've use the ecalc chart and felt things should have been ok, and when using plastic slow fly props things seem fine since I've used this setup for 6 month or so, but I'm considering reconstructing everything if I can't find a happy medium here.

Thoughts?

John

 

[RTRyder]

Today I tried something a little different. After reading many a motor spec sheet it seems the consensus is that if you use a 3s battery you can get away with a larger prop compared to using a 4s battery. I put a 3s 5000mAh on my F550 this morning and found that the violent vibration I was experiencing yesterday when trying to take off with the 4s 5300mAh battery was gone. Unfortunately what I also found is that the 3s doesn't have the balls to lift this craft off the ground effectively. End result, splintered two more 11x4 GemFan wood props when I landed and it pitched forward as I was disarming the motors.

At one point I felt I was taking one step forward and two steps back when trying to get these wood props to work but now I'm beginning to wonder how badly mismatched my motors, NTM 26-36 750kv, are with my prop and power choices. I've use the ecalc chart and felt things should have been ok, and when using plastic slow fly props things seem fine since I've used this setup for 6 month or so, but I'm considering reconstructing everything if I can't find a happy medium here.

Thoughts?

John

Everytime you make a change to the setup with a Naza flight controller you will need to adjust the gains, what works for one particular setup can be miles off with another. Another thing is did you balance the wood props before using them? It has been my experience that very few wooden props are balanced out of the package and can vary widely from one to another. With the motors you have and a 4S battery I would be using a 10 inch prop at most, more likely something in a 9 x 5 size.

FWIW, I find ecalc to be a very general guideline and not particularly accurate so take what it says as just that a general guideline and not an absolute perfect configuration.

Ken

 

[SamaraMedia]

Yeah, I balanced each prop, quite time consuming, which is what ticks me off the most is after spending all that time making sure they are balanced I can destroy them in less than 30 seconds with a slight miscalculation. I've used 10x4.5 props, can't remember is I tried the 9's, but the 10's didn't seem to give me much time in the air before the low voltage alert began to blink which frustrated me because when I would land and check the battery for usage it wasn't near the 20% mark so I could have probably got a few more minutes in flight. I just didn't feel comfortable flying with the warning signs flashing, although I've read many turn it LVW off in the assistant, you just need to be sure you have an accurate account of how long you can fly before draining that battery down to its limit and since I just recently purchased a voltage reader for the battery to get an accurate measurement I have been reluctant to do so. If I knew I could only get about 5 minutes from the batteries then I could go by the timer on my TX. It's all trail and error, so far a fair share of error.

I think I will try the 10's I have and give it another go although the wind is blowing pretty strong today, not a great day to be testing.

Thanks Ken.