I've tried everything on here but it still wobbles and flips on takeoff.

Hi all,

So this is the first time I've sought help on here since I got my first APM (2.5 latest firmware).  I've managed to make it this far with all the good info here and in the wiki.  Here's my kit, followed by my problem.

Stock Gaui 330X-S

Spektrum 2.4Ghz Rx and DX6i Tx

So, I had the above taking off and hovering no problem with the stock ESC's (see here for make up of parts)

The ESC's that come with the quad are reputed as being of low quality so I decided to replace them with something a bit better to see if I could make it fly a bit smoother.  These replacement ESC's come widely recommended, so I got some.

Cut a long story short, I cut all the connectors off my old ESC's, soldered them all to the new ESC's and rebuilt my quad with the new ESC's.  Eventually figured out how to calibrate them (which I did manually) and I'm confident this has been done correctly (as I did it several times before locating the instructions and doing it properly).

My problem is, quad wobbles and flips immediately after leaving the ground.  I've ran through all the troubleshooting steps in the wiki numerous times yet I'm still experiencing the same problem.  The only thing I can't get working in the test is the motor CLI test:

Have you run the Motors command in the CLI Setup to ensure that all the motors are hooked up right, turning the right way and the pusher/puller props are on the right motors and oriented the right way?

The motor CLI test simply does not work for me, it just doesn't spin the motors as per instructions.  I have no idea why and I promise you I have quadruple checked that I have set everything up correctly.

  • All sensors tested and working
  • Radio Calibrated - all end points on 100%
  • Quad levelled
  • Props and motor in correct orientation, I can see which way they're going when they start/stop spinning from full speed
  • APM orientation fine (using 'x')

Here's the weirdest thing.  If I give the quad even just a little throttle then take my hands completely off the Tx, it'll sit there on the ground, all props spinning but they will very slowly speed up to the point where the quad will take off on it's own if I don't drop the throttle.

Another test I did was to hold the quad while giving it a little throttle.  It seems to work exactly how it should when I do this in that it will correctly compensate if I tilt it in a given direction.  If I only lightly held it, it tended to start wobbling.

I've tried everything that seems to be listed on the forums/wiki but am at a loss.  Could it be that I need to do some tuning of PID's before I can even get it to take off properly?  I didn't need to touch a

thing with the stock ESC's to get it hovering ok.

Please see my quick video of it increasing the throttle by itself and the flipping.

Flip Vid

Sorry about the "War and Peace" entry.  Any suggestions/questions are more than welcome.

Thanks.

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Now that is all out of order, and I think you should read it yourself.....But there is a lot of talk about using the  VERY clean power, and all of the problems it can cause.

I wonder If maybe just one of your ESC's was noisy, corrupting all of them. Id say you should go back and try just plugging in each on seperatley and seeing how it flys, But you cut the cable (which I can relate to) in fact that probably was the problem....

However if you want to set this thing up for the most power, (and the cleanest) I would pull of the JP1, and run a BEC to the input side, and either use your current configuration for the output side, or use another BEC.

I mention this because if you look at a quality BEC It's got all kinds of power filtering, whereas on a ESC the built in BEC is soldered on the same board as electronics that are putting out allot of noise. Plus when we use cheap ESC's, were also using a cheap power source.....and the BEC portion on an ESC is more of an afterthought.

Obviously plenty of people are running fine without worrying about any of this....but it just seams like were relying on the cheapest part to run the whole thing. A chain is only as strong and all of that.

When I had the ESC's that you are using, everything was fine exept the camera gimble solenoid was twitchy. Taking off jumper 1 and adding a BEC fixed the problem. So on my new setup.

I'm going to use one of the Blue series I just bought for the output, and my $6 BEC from HK powering the input.

(Id be flying it now, but I burnt one of my ESC'c and I forgot to order extras...... LMAO)

Oh and for what it's worth, diydrones built there system using only on of the ESC's power:

Now this is a mixture of experience and ALLOT of Speculation on my part, so I would be interested to hear your thoughts on this..

Those esc do not seem to have much adjustment you can select cutoff voltage and brake on/off but from what I see they have the  throttle response fixed and do not calibrate to input range.

Are these really recomended?

 

Personally I had started with the non programmable little brother of these ($5.99) but now that I know a little more Ive moved to the Blue Series / Mystery Series ESC.

I recommended them once to somebody, which I regret, But to answer your question I havn't seen them widely recommended myself. In fact from what Ive heard.....without the flash mod there not very good, and the BEC inside them is paticulary noisy.

There is a thread about the flash and from what I have heard it will give them all the right settings and what not, which makes them a viable option. It's one of those things that when your new you thing you can cheap out on...

Wow that tool will make it much more easy to flash.

I use only simonk  flashed  esc  because I  found it the only way to get rock solid stability.

But the stock esc should not flip.   When a copter flips or is really unstable trying to take off it has always been for me

1) Sensor orentation was wrong  for X or + mode 

2 ) Motor order was wrong

3)  ESC  had lost calibration

4)  Radio channel was wrong

 

Somewhere I have seen where people have had a bad one of those ESCs  where the throttle was out of wack and it is fixed so you have to change it out.

 

If you can throttle up just a bit and  and cause it to move forward , back , right , left  ok then it sound like it is mostly good  if it is out of wack and sensors are not correct the slight contoll movement gets amplified and you get the violent flip

 

 

Yes, I definatley think that double checking to make sure each motor is assigned in the right order, the props are in the correct push/pull config, etc.

Starting from a fresh flash resetting everything to defaults and going from there isn't a bad idea either.

Oh and making sure that all the props are at least roughly balanced would be a good idea as well.

John, what ESC's are you using, and did you go a "before and after" with the flash?

Everything I Keep hearing about is people who were plagued by wobbles  they can never get rid of, and flashing them with this firmware solves it like a magic wand. So hearing from someone who has actually done it would be much appreciated.

Oh and about putting your quad on the ground and spinning it up to a just before takeoff speed.....and then having it slowly takeoff on it's own could be caused by certain modes.

In fact that would make perfect sense. 

I would double check that your in stabilize when the quad is fired up (which would be super easy if you have telemetry)

It should not arm if other than  Acro or Stabilize but  yes I did mean say  to say check that it is in stabalize

Some have said that they take off in acro mode and switch to Stab mode.

I can see this due to the fact that the Stab mode gets the accel  involved in causing correction that leads to  more viloent moves if someting is off  including way out pids

Will not sure about before/ after.  I setup with stock and the tried first and then  flashed yes , night and day . In my mind trying to compensate for the non linearity and delay with "PID tunning"  is not very satisfactory just my 2c.  I use the HK F30 flashed , they have the flash signals in a nice row on the edge you can just  peal back a bit of hs.

 

I was thinking maybe loiter.....

Hi,
I'm having exact same problem with my arducopter.After I changed ESCs and Battery. It started wobbling like crazy and when I try to fly it, at some point it flips. A couple of times i managed to elevate it to 1 meters and tried auto-landing, and it worked.

Everything is okay, sensors, radio, board heading, prop rotation, red wires cut.

I cant get motors to spin in CLI Test/Motors too.

http://www.youtube.com/watch?v=Wcjm-07PsWg

http://diydrones.com/forum/topics/arducopter-3-0-1-wobbles-and-flip...

The fact that your motors come slowly up to speed suggests that the ESCs are set to "soft-start." You need to program them for instant-response. Some ESCs (e.g. Castle) come with gadgets that can be used to set this; others have to be flashed via a more complicated process.

My ESCs are HK Blueseries 40a Mystery SBEC.

They are programmable but unfortunately i didn't order any it will take 2-3 weeks for me to get them :/ I'm good at electronics maybe i can flash them with onboard connection or something. I better search on that.

The international warehouse has programming instructions here:

http://www.hobbyking.com/hobbyking/store/uploads/696063666X137641X4...

At least I believe that these are your ESC's.

 

-Mike

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