Gimbal jitters, how to fix?

[dockman]

So looking for some input on my gimbal and the jitter in the pitch I cant seem to get rid of. 

I have tried many different settings with no luck getting rid of the jitter so I am thinking it might be a mechanical problem.  The jitter only seems to be in the pitch and only occurs while flying and seems worse when it is windy.  The only way I can duplicate the jitter on the ground is by lightly tapping the bottom of the camera on the pitch axis.  Soooo, my idea is that it might be the gimbal motors are not strong enough to hold the camera steady in the turbulance that the wind creates. 

Can a jitter be contributed to an underpowered motor?  Regardless of the power setting I use it continues to have the problem. 

[steve fh]

Hi.

I had a issue similar issue on my TCtimer gimbal which turned out to be a duff motor.

You can test the motor by disconnecting the motor from the camera mount and then powering up the gimbal. When you then move the IMU the motor should then rotate smoothly as it tries to level the camera.

My duff motor stepped or cogged when tested as above.

I could also be a slight balance issue.

[The.Quadfather]

dockman, which software are you using ?

the jitter could be too little power, but alternatively it could be that the P or D setting is too high

[dockman]

2.40b7 alexmos.

I have tried everything between 80 and 180 for power with higher power making a negligible difference.

I have however had a though about the PIDs, with a lower P the resolution is lower for the corrections leaving more distance between each notch if that makes sense.  When tapping the gimbal there was a minute amount of movement in the motor which is what I am assuming is where the jitter comes from.  Earlier today I turned up the P pretty high which increases resolution and that wiggle room was made almost nonexistent.  I retuned the other settings and put the power up to 120 and now when I tap it you can barely notice any jitter.  I will have to do a flight test to confirm this has worked but it is looking good so far.

(update) Did a quick test in the back garden, jitters are still there just a lot smaller.  Will upload a short clip to show what is going on.

[dockman]

If you watch closely you can see the occasional jitter/shake, unfortunatly youtubes video processing makes it a tad harder to see but it can be spotted here and there through the clip.

https://www.youtube.com/watch?v=jTSEHYypar0&feature=youtu.be

[Oakie]

when camera is out of gimbal does the gimble still do it?

[The.Quadfather]

If you watch closely you can see the occasional jitter/shake, unfortunatly youtubes video processing makes it a tad harder to see but it can be spotted here and there through the clip.

yeah, see what you mean @ ~00:35, does it only occasionally   

[dockman]

Gets worse when it is windy out, a lot worse, pretty much constant jitter. 

Camera is about 450g and the motors are 4108';s which should be plenty for that weight.  But it is as if there is a dead zone between poles with a tiny amount of wiggle room.  I swapped the pitch and roll motors around to see if it was a bad motor but still does the same, so unless both motors are junk it should be good.  I will see if I can record the wiggle room with my mobius and toss up the video.

What is really annoying is I can get the gimbal buttery smooth indoors moving it by hand, but as soon as it is in the air the jitters start.  If it was a hand held gimbal it would be fine, just dont like wind for some reason.

(update)Might be hard to see as it was a little close for the mobius to focus, but here is a video of me trying to demonstrate what I am talking about.

https://www.youtube.com/watch?v=vkMY06xt9u8&feature=youtu.be