At a total loss, need help

[Blacksails]

Finished up my Droidworx AD8 HLE with wkm today.

I did the following:

Set all throttle ranges on esc's
Made sure IMU was pointing forwards
Made sure that GPS compass was pointing forwards and also calibrated it
Balanced the props/motors
Made sure that all motors and props were spinning the correct way
I also measured the x,y and z axis points as close as humanly possible and sorted the CG.
Had all my basic gains set to 200% and my attitude gains set to 80% as I read these were ideal starting points for a bigger ship.

Everything was responding as it should and all looked to be good so I took it to the field. I had perfect lights (GPS, attitude and manual), set her to attitude mode, armed it and the motors spun up. I eased up the throttle and the motors began to rev up and down by themselves, I left the throttle stick where it was and the revving continued for a few seconds and then it flung itself into the air incredibly fast. It was yawing (happend too fast, not sure whether it was left or right), I paniced and lowered the throttle (definately NOT below 10%) and the motors stopped all together and it dropped from about 10 feet completely destroying the landing gear.

I really dont have a clue what could be wrong. In my eyes the setup was perfect. Is a vertical gain of 200% far too high? and why the yawing?

Incredibly frustrating! I've scrimped and saved for this kit and it destroyed itself withing 5 or 6 seconds.
I've built many micro and standard sized multi wii powered tris quads etc and have never had a problem like this. I expected FC that you dont have to assemble yourself to be slightly simpler to get into the air.

 

[robvree]

Oh man, so sorry to hear this. I'm sure with the amount of knowledge on these forums you will figure it out.

I'll throw out some of my thoughts and ideas:

- What was the WKM LED showing you? Was it blinking yellow, then pausing, then blinking again? Or was it a steady blinking yellow?

- Even if you did move the throttle below 10%, the motors won't cut off for 5 seconds so I doubt that was the reason the motors stopped. Are you sure they actually stopped before it hit the ground?

- Did you do any bench testing with the props off? Did the motors run smooth?

- How was your battery? Was it charged completely? Did you have voltage protection turned on in the WKM? If so, did you have it set to the correct cell battery and calibrate it to your battery?

- You mentioned you set all the throttle ranges of the ESC's. Did you do each one individually without the WKM involved?


I sure hope you figure this out.

 

[Blacksails]

Hi Robvree

Thanks for the help matey.

Not sure on the LED, it was blinking yellow, then pausing, then blinking I think....

The motors definately cut off completely. I do have it set to Immediately rather than intelligent cut off, but the throttle was above 10%

Bench testing all the motors appeared to be running smooth and at the same speed. Wobbling the copter produced the responses you would expect to keep it level.

Batterys are brand new 5s 5500mah and were charged

Each ESC was plugged directly into the reciever and each one was set individually. I started with the TX throttle stick at max, powered the esc, waited for the bleeps and then reduced the throttle to 0. I then had the confirmed setting bleep.

As it flung up into the air it remained level, which at least tells me that it was stabilising, but the yaw was quite severe.

I now have to find a UK supplier who has stock of the gear rail tubes and gear rail mounting brackets, every single on is knackered. They seem to be designed to sacrifice themselves in the event of a crash, which worked as there was no damage to the actual copter except for a few props.

Cheers

 

[Blacksails]

Just done another bench test without props.

If I set the motors going and then leave the throttle low the motors seem to hunt up and down for 4-5 seconds before finally settling down. This is what they did on the flight before it fired off up into the air. Is this meant to happen? is it just the WKM getting used to its current altitude?

Also, it doesnt matter how many times i calibrate in the assistant software, my tx sticks are never exactly center, they're always just slightly off. Could this have caused the Yawing that I saw?

Cheers guys.

 

[redridinghood]

Did you set the mode switch and failsafe corectly?
Sometimes if you set the trim to barely turn blue, in assistant soft. the craft goes in and out of failsafe.
Also what brand esc motors you use?

 

[Blacksails]

The switches have been set properly, at each setting the arrow is dead in the middle of either GPS, MANUAL or ATTITUDE.

My entire setup is as follows:

Motors are Torxpower 3536 (tiger motor rebrands I think)
ESC's are Hobbywing 40A funfly/pentiums.
RX is EZUHF
TX is FUTABA T9CP with EZUHF module
10x4.5 props
DW AD8 HLE frame
Photohigher AV200
Lipos are GensAce 5500MaH 18.5v 25C

The GPS/Compas is positioned out on one of the arms and quickly gets full lock.

 

[meme]

Hi Blacksails,

i`ve encounterd the same problem today: Copter goes up without any command from stick, no reaction on R,A,E, than he cuts the motor at about 3-6 feets. Had this Problem 3 times today.
I`ve had some green Light blinking on the LED wich means an Error in IMU Connection, did you had that too? Also i have that problem since i have setted Fail-safe yesterday evening, sitting here and trying to figure out.... My Luck, the DJI 550 is incredible stable, only 2 broken props...


meme

 

[Blacksails]

No, I didn't have any green error L.E.D lights and I haven't even touched the fail safe yet. Frustrated!

 

[srbell]

I thought the green led meant you're in IOC mode?

 

[meme]

I thought the green led meant you're in IOC mode?

@ srbell, i had 3 green and 1 red flash in GPS Mode, according to Manual it's Error in IMU Communication
@ Blacksails: I've took a couple hours off today and did a few changes: Moved the IMU from Center of Bottom Plate to the Back and wired all new and tightly, fixing everything with Cable Ties. So the IMU is distant as far as possible from the GPS.
Added M3 double Foam Tape to the whole Plate of the IMU, not only a strip like before. Had some hovering in my garden then without any problem then, for now.

-meme

 

[Blacksails]

Ok guys, so what is the throttle response supposed to feel like in attitude mode?
I'm about ready to try again and have lowered my vertical gain to 150%, I've heard this slows the climb/descend rate. I'm used to your standard multi wii/ rc heli response.

Does the dji usually jump into the air and then settle and hold altitude? Last time it was off the deck before half throttle and climbing, which is when I cut the throttle.....I'm thinking I may have panicked and cut the throttle before it settled itself?

I've reset the cut off to intelligent mode to see if that helps, but my worry is that if it all goes wrong again then the throttle won't cut for 5 seconds meaning if it won't descend it'll be falling from a much higher altitude

Also, I reset my esc throttle ranges again, and the bleeps that occur (which I believe indicates the number of cells) were reading differently. Some read it as 3, some 4, and some correctly 5. Is this a problem? I don't think it should be but just checking. All the esc's are set the nimh low cut off

Cheers

 

[meme]

Ok guys, so what is the throttle response supposed to feel like in attitude mode?
I'm about ready to try again and have lowered my vertical gain to 150%, I've heard this slows the climb/descend rate. I'm used to your standard multi wii/ rc heli response.

Does the dji usually jump into the air and then settle and hold altitude? Last time it was off the deck before half throttle and climbing, which is when I cut the throttle.....I'm thinking I may have panicked and cut the throttle before it settled itself?

I've reset the cut off to intelligent mode to see if that helps, but my worry is that if it all goes wrong again then the throttle won't cut for 5 seconds meaning if it won't descend it'll be falling from a much higher altitude

Also, I reset my esc throttle ranges again, and the bleeps that occur (which I believe indicates the number of cells) were reading differently. Some read it as 3, some 4, and some correctly 5. Is this a problem? I don't think it should be but just checking. All the esc's are set the nimh low cut off

Cheers

Hi Blacksails, when that happend, have you flown in Intelligent Modus? Motors don`t have to cut in intelligent modus, anyway.
Did you felt any response from the other Sticks? (R,A,E)
I think we are dealing with quite the same problem here. That happend to me yesterday Night: http://www.youtube.com/watch?v=4Hhzr1bfpaE I was not at the sticks at all after arming.
In my case it`s a bit strange, cause i had some great flight in the Noon without problems.

 

[quadcopters]

Meme , 3 lights flash green and then 1 red means it as just defined home lock , and 1 red will mean it is on the way to finding satellites .

Alex your vertical gain sounds high , try about 120 ish .

Geoff

 

[meme]

Meme , 3 lights flash green and then 1 red means it as just defined home lock , and 1 red will mean it is on the way to finding satellites .

Alex your vertical gain sounds high , try about 120 ish .

Geoff

Hi Geoff, i have no Home/Course Lock setted for now, 3green/1red Leds blinked 3-4 times than switched to normal blue Led (GPS) again.

 

[Blacksails]

Hi Geoff,

Thanks for the super fast delivery of my new landing gear. Got it built up just.

I'll knock the vertical down to 120.

My other gains are 250 for pitch, 250 for roll and 200 for yaw. Sound ok?

Meme, I definately have control of roll pitch yaw etc

Cheers

 

[Blacksails]

Ok so tethered the beast down and tried another flight. She's tethered so that she cant fly higher than 3 feet. All controls respond as you would expect when shes on the deck, if i power up the motors everything works (aileron control tilits her, elevator tilts her and rudder spins her) but as soon as she lifts off of the ground the rudder does nothing and she will NOT descend unless you perform csc to cut the throttle. If she hadn't been tethered today i have a feeling i would have lost her.

Really need some help as i just cant figure this one out

Cheers

 

[Blacksails]

Also she yaws like crazy whilst airbourne which no stick input will fix.
Lights were perfect, solid yellow flashes for attitude.

 

[Shoryuken]

Hi Geoff, i have no Home/Course Lock setted for now, 3green/1red Leds blinked 3-4 times than switched to normal blue Led (GPS) again.

If you have not ticked the IOC in software, do you get IMU lost/error warning when green LED blinked?

 

[quadcopters]

Alex would you be able to have a drive to my place so I can have a look at things for you ?
Might be something and nothing but at least if I get to look at it then hopefully we can get you airbourne .
200 for Yaw sounds high to me personally , I am normally at around 120 for most my builds on Yaw

I also think some pics might help , show some of the centre plate with electrics and then some with the GPS module and how everything is laid out .
Are all the motors definitely going the direction they should be and you have it as the right OCTO in configuration settings . There is OCTO X and Octo +

Regards your esc's what settings have you got them at ? Are they all making the start up beeps together and in tune with each other ?


Geoff

 

[Blacksails]

Hi Geoff,

Thank you very much for the offer to take a look at it personally but i've managed to fix it. Appreciated.

Feel like a complete idiot. I was extremely OCD about labelling my ESC wires so that I knew which motor each esc wire went to. I was so paranoid about this that I did it 3 times during the build. It turns out that this paranoia was my downfall. I had labelled 3 of the esc's wrong, throwing all of them out in regards to where they were plugged in. If I had trusted myself the first time round and not decided to over worry about them then the chances are I wouldn't have had that expensive crash. Oh well, lesson learned the hard way. Feeling a complete and utter twonk.

Thankyou for the help guys and sorry for wasting your time with my idiocy

She flys beautifully now! First flight she was holding steady as a rock in GPS mode and responds really nicely in attitude. In the next week or so I will be setting up the pmu and sorting the failsafe out.

Thanks to all of you!

Cheers