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Old Jul 15, 2012, 02:42 PM
Fly, crash, rebuild.
United States, NY, Shelter Island
Joined May 2011
878 Posts
Tricopter Yaw servo wobble

Got the KK2 in my tricopter. I have a servo death wobble. Yaw Gains
A sloppy
PG: 20
Pl:20
Ig:20
Il: 10

Roll and pitch gains are locked in around 40/100.

High yaw gains make wobble worse.
I'm using a Turnigy TGY-53317M. $5-6 servo.... couple hundred flights on it, many crashes too. Could be the servo is shot. Worked well on KK1 V2.1 with KK1.6 FW, she was no problem.

Anyone else experience a servo wobble?

Yaw function is fine and pretty good. Board was easy to set up, flew in 15 min from taking KK1 off to hovering.
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Old Jul 15, 2012, 02:44 PM
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Joined Jun 2011
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Quote:
Originally Posted by Del-Dredd View Post
"Self-leveling. It uses acc tilt-angle measurement. Later I will try to add a full AHRS algorithm like the big boys use since it is better. (less delay)"

I did not say it was a coding problem either but ACC only has its limitations.

I would not like to try the Frisbee test for example.
I believe that has very little to do with crafts that have erratic flight behavior and wobbling issues.
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Old Jul 15, 2012, 02:49 PM
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Joined Mar 2012
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Any chance of finding out more information on tracking down a replacement lcd? I cracked mine on a failed flip. The board still works, but now I can't change any settings. I took out the lcd, but I don't see any markings to help identify it.
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Old Jul 15, 2012, 02:49 PM
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I originally was building a quad with the multiwii board in mind but it was just too much for a newb, so I said hell with it and got a KK2. On the multi wii it only uses 1 wire for the AIL RUD THR, so do I need to get new wires with all 3 wires to attatch to this board or will it work with only 1? Just trying to figure out the wiring on this thing. Thanks, Aaron
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Old Jul 15, 2012, 02:59 PM
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Quote:
Originally Posted by HappySundays View Post
Here you go. Easiest way to fix this problem...
Note also my LiPo measurement connection points.
While not entirely necessary, it is good practise to run a separate ground like shown.
I went and tried that on the KK2 I have mounted on a wing and while now the servos are active, all they do it twitch and the throttle twitches as well. Randomly speeding up and slowing down.
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Old Jul 15, 2012, 03:03 PM
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The Netherlands, UT, Soest
Joined Feb 2012
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Quote:
Originally Posted by bobepine View Post
That's not a KK board problem. It's a setup problem. So many things can be setup wrong that will cause such issues. The KK2 is working well for many, many users so deductive reasoning points to different things than the KK2 board as a cause for unwanted flight characteristics. If it was a coding problem, or lack of, then every pilot would have the same issues. Not only "some" pilots.

Best,
Chris

sorry, but i think you are wrong.
the KK2 just doesn't have the "self level" as other boards have. it does not "snap" back to level as other boards do.
it has nothing to do with the craft it's mounted on. it's the KK2.
i have a quad with FF, i took of the FF and put on the KK2. it's rock solid WITHOUT SELF LEVEL, but put self level on and it's a nightmare compared to the FF.
if it would be a hardware issue the quad would be badly behaving with the FF also. (or with multiwii or the rabbit i have, but it doesn't)

the pilots who have always only flown with KK and other gyro only boards have nothing as comparison to AL, so they don't have any troubles and think it's all ok.
the ones who fly with AL boards like FF/multiwii/rabbit/naza etc etc know how autolevel should behave, and they know the KK2 isn't great with AL. (yet)
Al is just to slow it only works if you have a multi that is very sluggish and slow to react to input. if you have a nimble multi AL is to slow.

i have spend very much time on tunning my KK5.5 board and i take that as a comparison for the KK2 without self level. in this case the KK2 blows everything away. it's that good! but autolevel of the KK2 compared to any other selfleveling board just isn't up to par. and it has nothing to do with the platform it's mounted on.



Quote:
Originally Posted by mudman_94 View Post
I originally was building a quad with the multiwii board in mind but it was just too much for a newb, so I said hell with it and got a KK2. On the multi wii it only uses 1 wire for the AIL RUD THR, so do I need to get new wires with all 3 wires to attatch to this board or will it work with only 1? Just trying to figure out the wiring on this thing. Thanks, Aaron
it will work with 1 channel with all three wires (signal, positive and negative) and the other three/four with signal only.
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Old Jul 15, 2012, 03:06 PM
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Near Aberystwyth - Wales
Joined Aug 2004
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Quote:
Originally Posted by mudman_94 View Post
I originally was building a quad with the multiwii board in mind but it was just too much for a newb, so I said hell with it and got a KK2. On the multi wii it only uses 1 wire for the AIL RUD THR, so do I need to get new wires with all 3 wires to attatch to this board or will it work with only 1? Just trying to figure out the wiring on this thing. Thanks, Aaron
Do you mean you were using CPPM ie just one wire for all the Rx to board information or you had a three wire for the Elevator connection and a single signal wire for each of the Ruddr, Aileron and Throttle.

If the later, that should work just as well on the KK2 I would have thought, you only need the one 3 wire lead to the Rx to supply power and a ground.

Dutch beat me to it.
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Old Jul 15, 2012, 04:41 PM
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Good deal, thanks for the help guys
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Old Jul 15, 2012, 04:42 PM
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Quote:
Originally Posted by chiloschista View Post
Just a few paper where to start from :

An improved method for accounting for acceleration in gyro roll-pitch drift computations

Measuring Tilt Dynamics of Multicopters

Or you could have at the UavDevBoard code repository and site project

Ric

P.s. : this is Bill Premerlani's work, with some other developers
Did you actually read any of the papers you linked?

The first one is for fixed wing aircraft and uses a GPS, the second one is about tilt dynamics and rotation rates. We are talking about the autolevel of the KK2 board using an accelerometer.





Quote:
Originally Posted by Del-Dredd View Post
"Self-leveling. It uses acc tilt-angle measurement. Later I will try to add a full AHRS algorithm like the big boys use since it is better. (less delay)"

I did not say it was a coding problem either but ACC only has its limitations.
Only looking at Autolevel as well not normal flying, loads of praise for that but numerous posts on unstable Autolevel.
If it is only setting up on Auto Level, maybe Rolf's new guide will help.

I would not like to try the Frisbee test for example as it is.
I agree, to stabilize a craft you first need to stop all rotations, that need gyros. Then you return it to level.
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Old Jul 15, 2012, 04:55 PM
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rcbif's Avatar
United States, OH, Medina
Joined Jun 2005
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Quote:
Originally Posted by shelterock View Post
Got the KK2 in my tricopter. I have a servo death wobble. Yaw Gains
A sloppy
PG: 20
Pl:20
Ig:20
Il: 10

Roll and pitch gains are locked in around 40/100.

High yaw gains make wobble worse.
I'm using a Turnigy TGY-53317M. $5-6 servo.... couple hundred flights on it, many crashes too. Could be the servo is shot. Worked well on KK1 V2.1 with KK1.6 FW, she was no problem.

Anyone else experience a servo wobble?

Yaw function is fine and pretty good. Board was easy to set up, flew in 15 min from taking KK1 off to hovering.
In my option and a few hours of messing with the yaw, it is a error in programing.

It makes my tricopter useless for aerial video as it puts tons of vibs in the frame.

Please post here so it stands out as a problem.
http://www.rcgroups.com/forums/showthread.php?t=1691880
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Old Jul 15, 2012, 05:16 PM
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Riverside, Ca
Joined Oct 2006
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I am trying to put the KK2 on a 4 channel fixed pitch heli. The rx test is correct and the motor works but can't get the servo's to move. in the mixer editor I have pitch,roll and yaw set to 100 and set to servo. Any idea's. thanks
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Old Jul 15, 2012, 05:18 PM
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United States, IN, Kokomo
Joined May 2008
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@ rcbif Ditch the cheap analog servo, that is the problem. Get a decent digital servo. I know that on many multiwii and 32 bit controllers they have a faster refresh rate. Some are even selectable i.e. OP Copter Control.
A person would think that if you have big plans for your aircraft that you would spend more than the bare minimum.
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Old Jul 15, 2012, 05:23 PM
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United States, OR, Portland
Joined Apr 2011
385 Posts
Quote:
Originally Posted by rcbif View Post
In my option and a few hours of messing with the yaw, it is a error in programing.

It makes my tricopter useless for aerial video as it puts tons of vibs in the frame.

Please post here so it stands out as a problem.
http://www.rcgroups.com/forums/showthread.php?t=1691880
Yeah you really need a high speed digital servo... At a minimum spend $20 for a good one. I have a $5 analog metal gear on my tri and had to really turn down the gains and tune it to get rid of the wobble... after that it flies just like the original kk. But after upgrading the servo I could bring the gains back up to stock settings and is nice. FYI, metal gear servos will induce more vibration than nylon gear.
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Old Jul 15, 2012, 06:20 PM
Team White Llama
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USA, IL, Mundelein
Joined Mar 2005
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Hello all. I am really diggin this new KK2 board. I never use autolevel, I want to be the pilot not a passenger. Here is a vid of my maiden los flight. Total setup time was a little more than 5 min. I went out it felt great so I ripped on it pretty hard.
Hobbyking KK 2.0 Maiden flight (6 min 1 sec)
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Old Jul 15, 2012, 06:33 PM
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Riverside, Ca
Joined Oct 2006
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Man good job. that is some kick a$$ flying.
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