Hi guyz,
I am building a quad with the specs..

HK quad control board with stock + config......(from RCHobbyAddict)
4 x 1400kv motors (0.8 kg thrust)
4 x 30 amps esc.
frame is custom built.

Well the problem with my quad is its continuously yawing  

the basic problem to look for yaw is to look at angle the motor shaft has with the other end motor...and I checked that...its parallel to the other opposite motor shaft. But still my quad yaws.

I tried to adjust the trim the yaw stick on the transmitter...but it starts to yaw in other direction...either direction...it yaws    

I have noticed a slight difference in the speed of the motors when I give abt 10% - 20% throttle.

So i was thinking the of testing the motors and esc for errors.
Already dry tested the motors with multimeter and winding seems to be okay...but dont know how to test the esc...(note: esc and motors are running and arming ...need to test if there is variation in speed on same signal value or constant signal.)

Need help from the pros...completely newbie here...its my first quad build.



(If I posted in the wrong section...plz correct it....sorry)

Reverse yaw gyro and then try. Also put some dual rates and expos on rudder and then try to stabilize it.

trim yaw pot of board and yaw stic of radio and check prop band and corect cg of quad 

I have the same problem man... cant find the problem i just continues to yaw.. I was working fine until one of my board (place where you mount electronic) broke in a hard landing. Then i substituted that with Carbon Fiber plates but ever since then i am not able to get a good fly it just yaws.. Its so damn frustrating tried yaw pot, trim but nothing helps.. 

You are using CW and CCW props, right? Try to center the yaw channel of your Tx.

So it started after a crash, and you changed the platform on which the controller sits, right ?  In that case, the first things to look at are :

1. the mounting of the board. How well is it damped from vibrations ?

2. other damage in the hard landing that affects motors/props. Have you tried interchanging the motors ?

 

about props Offcourse yea man they are CW and CCW.. "Center the yaw channel of ur tx" u mean trim???


Yes anwar, i have changed the platform.
1. hmm you seen the soft box in which HK boards comes in?? i have used that.. also i have used that to how the hk board to the platform

2. Nothing else was damaged in the hard landing apart from the platform breakage.. never tried interchanging the motors shall i try that??

check here reply #21 i have added images.

@spitfire....yaw gyro seems to be right...bcoz
I moved the quad CW and front and back motors are speeding up...
...is that right?

Good that some one brought this up! I had the same problem but was intermittent. First time it was due to not having the throttle range setup. Once it was done, then all the motors spooled up evenly and got stable yaw. With out this, after trimming out the issue, when the battery charge changes,  then the problem reappears. Then it was the orientation of the board in comparison to the mount board. I had to point the arrows dead center between two motors (in x config) to tame the yaw. I am still looking for the soft spot (both hardware as well as trim). Would love to hear from the experts