Iflight DC3 flies like crap - is it just me?

[Dillwhacker]

I just bought an iFlight DC3 with on board DJI HD system, as all reports of it were that it flies like a dream..
Mine doesn't... It has a strange random twitch in the yaw direction.. look here..
https://www.youtube.com/watch?v=M29hCSEwfVo

The instability is yaw only, so I can only think its the yaw gyro at fault..
A problem with a motor, or prop, or ESC would result in wobbles in pitch / roll as well. so I think its a yaw only issue.
Betaflight shows the transmitter yaw signal looking perfect.

Any suggestions would be very welcome!
Taaa
Trev

[ched]

Double check motor bolts, FC soft mount may be too tight too loose, yaw P maybe too high, try half current value (make CLI backup first). All motors feel same? Check solder joints all look nice and shiny.
Have you looked at blackbox log, that might show gyro issue?

Really silly question but is yout tx OK? I once wore out a potentiometer on a gimbal and that got twitchy.
Just sort of guessing really, hoping that something may trigger an idea.

Good Luck and let us know hoe you get on.

[FPVSteve]

I once had a similar issue on my TBS Discovery - turned out that the servo lead for the yaw wasn't seated properly and the signal wire kept losing contact with the pins when the airframe was vibrating. It was seemingly random, but like yours it was more of a problem when I spooled up the motors.

But - are you using a single cable or individual motor wires? If SBUS then obviously that's not it

Horrible issue to have if it's inconsistent!

Do you think it could maybe be trying to RTH? i.e. rapid signal loss / regain?

[Dillwhacker]

Cheers chaps. OK...
Soft mounts look decent - slightly compressed but not squashed tight. I haven't fiddled with the PIDs yet, but will try. To me it doesn't look like a gain issue though, it looks like a random intermittent twitchy thing. Never done a black box log so will have to learn about that. Good point about the transmitter, it is a new but untested Taranis, but looking on Betaflight the bars seem to move smoothly from 1000 to 2000 uS.
It's SBUS Steve, so not the rudder servo wire. Not RTH cos there's no GPS !
This FC has two gyros and uses Betaflight to blend them together, so first plan is to try them individually and see if one is good and one is a duffer. Although they both look good on the configurator display.
To be continued...
Cheers.

[atomiclama]

If you have only a yaw twitch then I'd go with what you have already said.

Duff gyro. Get it replaced.

[Dillwhacker]

Yep, that's the plan, unless it flies sweet on the 1 out of 2 that seem to be fitted..
Will report progress....
Trev

[ched]

I seem to remember it's cli commands to switch gyros? That may have changed on newer BF.
Let us know how you get on.