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Tricopter Yaw Problem

#1
Hey guys

First post on the flitetest forum and actually any forum. I just rebuilt my tricopter and have found that when i begin to throttle up the yaw automatically begins to tilt and fix its self into one position until i have throttled all the way down. As soon as i lift of the ground it begins to spiral and i can't do anything about it. I don't know whats causing this or whats wrong :( I got the KK Board as my controller and havent had too many issues since i've had it.

I'm not too sure if this has been mentioned anywhere else on the forum, if so please guide me there :)

Any answers are appreciated!

ps. heres a video i took of what i meant: http://www.youtube.com/watch?v=iVQ6WebVxFk
 

Burg

Never catch a multirotor
#2
How strange .. did you reset the transmitter when setting up the channel ?
Looks like there is still some mixing left between throttle and rudder.
Did you exchange the servo alraedy ?
Did you flash the board (= reset) ?
 
#3
Yeah i have reset the transmitter, couple times actually. Maybe ill update tomorrow when i get my new controller (Spektrum DX8).
How would you get rid of the mixing... I'm clueless.
I've been through about 5 different servos, i had one good one that was standard sized and quite old but it worked better than any of my new ones. Shame it stripped when it crashed... i'm yet to flash the board, i'm not too sure how to yet.
 

Burg

Never catch a multirotor
#4
When you reset the channel on the Dx6i, the mixing is deleted too.
Did you try to move the motor further away from the servo ?
Perhaps the motor creates a magnetic field towards the servo or something.
Servo wire is influenced over the esc ?
Maybe a bad receiver ?
.. I dont know.

Wait untill you get the Dx8 and then see what happens.

For flashing the board try this :
http://www.rcexplorer.se/Educational/HKKK/HKKK.html
+
http://www.hobbyking.com/hobbyking/store/__21321__USBasp_AVR_Programming_Device_for_ATMEL_proccessors.html
 
#6
I saw your video and it looks normal to me. My tricopter does the same thing. i think the kk board is tilting that rotor to counter the torque of the motors. with mine, the motor stays tilted like that until I take off then it straightens out once in the air. The kk board doesnt know what kind of torque will be created when you spool up your motors. once in the air and the copter starts to rotate if its tilted too much should straiten out. if its not, i would suggest turning down the yaw pot resistor setting. I am on my first tricopter too so take my advice with a grain of salt because i may not know what i am talking about. sounds good though.

hope this helps
conrad
 

dezertdog

Senior Member
#7
This is exactly what my tricopter looks like during lift off. The gyros calibrate the moment you give throttle, over compensate on yaw and then correct once airborne.

What happens when you actually get airborne is the real question. Does it UFO (i.e. start to spin in a circle)? I've read of people using the XX firmware and getting a yaw gyro reversal scenario like this:


Most of us use KapteinKuK 1.6, which the guy in this video says solved the reversal issue.
 

genious

Junior Member
#8
I've found that when the throttle is all the way down on the KK board the yaw motor is moved away from the "center" position that the board uses for flight. When you add even a tiny amount of throttle the yaw servo will quickly jump to the "center" position.

The way I get round this (which may or may not be correct) is to adjust the yaw mounting with a little bit of throttle applied.

* Take the props off
* Add a tiny bit of throttle with the transmitter
* Servo moves after throttle is applied
* Adjust servo horn so tail motor is straight up
* Tighten everything up, bung the props on
* Fly!

Once this is done I find everything is OK 'til I next have a crash - which is more to do with my YAW mechanicals than the KK board!
 

abourdaa

Junior Member
#9
I am new to flight boards and digital TX & RX, my experience with RC is all Analog with jewel TX RX, i bought everything from the build for the bat bone and bought the bat bone, got it all together and I have this same issue.
I centered the servo when powered on, and centered the motor. When powered and armed the motor is perfectly leveled, when throttle is added the servo picks a random direction and begins to tilt that way and starts to spin wildly, I have attempted to throttle up quickly and get into the air and not matter how varied i attempt to launch i experience the same issue. I've followed countless identical how to's on setting up the KK2. I drove 200 miles in two days traveling to different local so called experts on multi rotors, I even bought different servos and even bought a newer and ridiculously overpriced $65 KK2.11.5 from these liars at a placed called UAVRC. They then told me they don't know how to work on a tri copter, I've be come extremely frustrated with the whole experience. Can someone point me in the right direction on how to solve this problem. I would very much appreciate it.