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Multicopter => Multi Copter => Topic started by: Coyote on April 22, 2014, 10:09:12 PM

Title: Yaw problem
Post by: Coyote on April 22, 2014, 10:09:12 PM
Hi guys, I have a problem ........... :(

I`m not sure if its motor related, ESC or flight controller so can`t decide which section to put it in but its a multicopter so this section will do :)

My Hex, that's been flying perfectly for over a year has now developed an annoying problem. It starts at random times Yawing to the right, some times a little and a small amount of stick input stops it, sometimes a lot and even full opposite stick only just holds it. Sometimes my stick input seems to have no effect on the yaw at all when its started this "drift"

This is wrecking my videos ! :(

Now, what will it be ? Will it be the Naza ? Will it be a motor beginning to seize maybe, or an ESC ? The motors spin freely, the bearings seem fine spinning in my hand, all props tight.

To be honest I`m really not sure and with 6 of everything its like looking for a needle in a haystack :(

Has anyone experienced the same and any idea ? 
Title: Re: Yaw problem
Post by: FPVSteve on April 22, 2014, 10:20:29 PM
Gusts of wind?
Title: Re: Yaw problem
Post by: Coyote on April 22, 2014, 10:24:11 PM
Hi Steve, the winds not ever a problem with the Hex, and it if you leave the stick centered keeps yawing around more and more
Title: Re: Yaw problem
Post by: iPeel on April 22, 2014, 10:24:29 PM
A lot of unscrewing and screwing, but you could try rotating all motors one position then see if it starts yawing in the opposite direction?
Title: Re: Yaw problem
Post by: FPVSteve on April 22, 2014, 10:39:36 PM
Do you have all the props going the right way? I realise this is like teaching a granny to suck eggs!
Title: Re: Yaw problem
Post by: Coyote on April 22, 2014, 10:47:20 PM
Hehehe :) Yeah mate, double checked just in case I was experiencing a blonde moment :)
Title: Re: Yaw problem
Post by: Dizzy on April 22, 2014, 11:07:48 PM
Coyote it may not be related but with my nasa quad last year when she crashed it was a yaw that caused it to start with :(

but i had experienced the same thing with mine where it flew fine but sometimes started to yaw and could hold it to start with, with the stick found no reason all props tight etc. In one flight i had full stick plus trim to land checked it over nothing i could see,  and flew again perfect  :(

It happened twice more but still never found the cause, So if you do find out why i,m interested as i am about to push the button on another naza  :+ for my hex 

dizzy :) 
Title: Re: Yaw problem
Post by: ClippedWing on April 25, 2014, 11:45:25 PM
I think its a ESC problem Ian!

You should buy new ESC's that are Opto stabilized!  :)
Title: Re: Yaw problem
Post by: marcin on April 26, 2014, 02:20:57 AM
Try and repeat sticks calibration in NAZA Ian ?..
Title: Re: Yaw problem
Post by: Coyote on April 27, 2014, 08:05:29 PM
I sat an tried a few things :

1) Swapped output 3 of Naza to output 2

This was to see if the problem shifted to motor no.2 and it was a Naza problem. It didnt so Naza was ruled out, it was something on the no.3 leg, either wiring, ESC or Motor.

2) Re-soldered the connections at both Motor and ESC end to eliminate wiring

Problem still was there so rules that out

3) Swapped motor 3 with motor 4

If the problem shifted to motor 4 then it was a motor fault, if it stayed at motor 3 then its an ESC fault. It stayed at motor 3. So I have a faulty ESC on number 3 and as it turned out number 6 if the stuttering was anything to go by when using the Naza Motor Test function.

With the motors swapped over I took it out to see if this was the case, and i it was a lazy motor the yaw would now be in the opposite direction now.

Well it didn't quite go like that :(

With a fresh new flash of the latest Naza, Basic and Advanced IMU calibrated, Mag calibrated, I brought the throttle up to 50% and the Hex spooled up and proceeded to flip over backwards. A reboot later and it did exactly the same thing again.

Bugger :(

My way of fixing this is a little drastic, but the ESC`s were not the greatest, I knew this when I bought them, but after over a year of fault free running I left them as is. I have now decided and bought the newer N-Fet Opto-Isolated generation and I`m going to swap them all.

I have also got some Tiger motors from Hase2 coming that I had previously tried and were impressed with.

Why change the motors ?

Well pancake motors are know to not work well with SimonK flashed ESC`s. Add to this I can not replace my motors like for like because they are not made in orange anymore, so I either have a daft looking Hex or swap all 6. Much easier to go with standard size low pole count motors that work with SimonK brilliantly and have better quality kit in it all round.
Title: Re: Yaw problem
Post by: krikey on April 27, 2014, 08:54:36 PM
Not sure if this helps, as my issue was KK2 related, but after a time of around 40 seconds, my quad started to roll over in one direction so aileron was required to adjust it. The more i stayed in the air the more it would roll to the right. If I landed, waited and then took off again it was fine for around 30 seconds and then the same.

I swapped around ESCs, motors and everything but the only thing that stopped it was a new KK2. I think my issue was down to a faulty/slow Gyro. Could a faulty gyro for yaw also cause the same?

Edit: is there such a thing as a gyro for Yaw coming to think about it. Or could it be a badly calibrated compass?
Title: Re: Yaw problem
Post by: Brod on April 27, 2014, 09:02:10 PM
when I used to fly naza,mine did similar,slight yaw to the right every so often.what cured mine everytime was recalibrating all the escs throttle end points,all done together of course..strange but never had that since I went Kk2.
Title: Re: Yaw problem
Post by: Dizzy on April 27, 2014, 11:50:24 PM
Quote from: Brod on April 27, 2014, 09:02:10 PM
when I used to fly naza,mine did similar,slight yaw to the right every so often.what cured mine everytime was recalibrating all the escs throttle end points,all done together of course..strange but never had that since I went Kk2.
thanks for that tip Brod :D

dizzy :)