HELP! Brushless gimbal vibrates & noise when tilting down. See video!

[ed.ge]

Hi

I balanced everything and the gimbal works GREAT. Very smooth video and all. The moment I tilt more than 45 degrees down the jitter happens + noise. Board is alexmos v 2.2

See videos!

PID is
14 0.1 10

Powered with 4s. It's the gotheli VX gimbal.


Any ideas how to solve this?
It does work without camera...

jitter
https://vimeo.com/84534308

i think it is well balanced?? (forget the first 3 seconds, I hit the gimbal)
https://vimeo.com/84534252

PS: Can I power the gimbal with 4s and still connect it at the same time via USB to my computer? Never dared to

 

[stanleyy]

according to video http://vimeo.com/84534252 it is not very well balanced. I can leave my gimbal in any position and it doesn't move at all. Yours is not holding position which is visible in the video.
Please check balancing on ALL THREE AXES. Many people forget to balance the camera along the vertical axis (Z axis). Gimbal then does "kind of" work, but as soon as you pitch it down, it starts to shake due to unbalanced vertical axis.

And yes, you can power the gimbal from your lipo while it is connected to USB.

 

[wm1]

according to video http://vimeo.com/84534252 it is not very well balanced. I can leave my gimbal in any position and it doesn't move at all. Yours is not holding position which is visible in the video.
Please check balancing on ALL THREE AXES. Many people forget to balance the camera along the vertical axis (Z axis). Gimbal then does "kind of" work, but as soon as you pitch it down, it starts to shake due to unbalanced vertical axis.

And yes, you can power the gimbal from your lipo while it is connected to USB.

I don't think you can tell how well balanced it is if you ignore the first three seconds as he says. From the remainder the tilt looks like it might be ok.

 

[wm1]

Hi

I balanced everything and the gimbal works GREAT. Very smooth video and all. The moment I tilt more than 45 degrees down the jitter happens + noise. Board is alexmos v 2.2

See videos!

PID is
14 0.1 10

Powered with 4s. It's the gotheli VX gimbal.


Any ideas how to solve this?
It does work without camera...

jitter
https://vimeo.com/84534308

i think it is well balanced?? (forget the first 3 seconds, I hit the gimbal)
https://vimeo.com/84534252

PS: Can I power the gimbal with 4s and still connect it at the same time via USB to my computer? Never dared to

I have the same gimbal with the V1 board. I powered mine up for the first time yesterday and it is exactly the same as yours with the noise and high frequency vibe. It does it when you tilt but it is actually the ROLL motor, if you unplug ROLL motor the tilt does not vibe (perhaps you could confirm if yours is the same).

I'm working on the problem and will let you know when I cure it, if in the meantime you cure yours could you let me know.

Do not power the board with USB alone if you have the motors conected, the USB supply is not enough and it will activate the trip the board. I always power my board with the main lipo as I think even with the 3 motors unplugged the 3rd. axis board can still be a bit much for the usb supply.

 

[stanleyy]

I don't think you can tell how well balanced it is if you ignore the first three seconds as he says. From the remainder the tilt looks like it might be ok.

he is constantly adjusting it.. it is not well balanced. And the crazy roll shake when it is pitched down is caused by incorrect balance on vertical axis. I have seen that many times in the past on my gimbals.
He has to adjust the position of camera up or down to find the correct COG.

 

[wm1]

he is constantly adjusting it.. it is not well balanced. And the crazy roll shake when it is pitched down is caused by incorrect balance on vertical axis. I have seen that many times in the past on my gimbals.
He has to adjust the position of camera up or down to find the correct COG.

It looks like he is putting into a position and letting go, if it stays there, which it looks like it does then it's ok. It's hard to show on a video because of the gogging effect of the magnets in the motors but when you are doing it yourself you get a feel for it.

Anyway, mine is perfectly balanced in all axis and it does the same.

 

[stanleyy]

It looks like he is putting into a position and letting go, if it stays there, which it looks like it does then it's ok. It's hard to show on a video because of the gogging effect of the magnets in the motors but when you are doing it yourself you get a feel for it.

Anyway, mine is perfectly balanced in all axis and it does the same.

I have been using 8 different gimbals at home, 5 of them for NEX cameras. And they all showed the same symptoms when the pitch was not balanced properly. There is no magic in it - as long as it is perfectly balanced, it will work. No matter how the gimbal looks like - it will work. It took me a few months to realize that it is always (!) my fault when the gimbal doesn't work properly. I was "sure" that the gimbal is balanced.. and it wasn't of course.
It is not a cogging problem - I used various motors in my gimbals (3506, 3508, 4008), versions with both 14 and 24 poles, made by TMotor, GBM and LD-Power. I could always tune the gimbal to perfection: wherever I left it, it stayed there. There was nothing like that type of movement I could see the video above. Look at the second 11 - this is WRONG. It stays completely off level on roll axis when the camera is pitched down.

 

[wm1]

I have been using 8 different gimbals at home, 5 of them for NEX cameras. And they all showed the same symptoms when the pitch was not balanced properly. There is no magic in it - as long as it is perfectly balanced, it will work. No matter how the gimbal looks like - it will work. It took me a few months to realize that it is always (!) my fault when the gimbal doesn't work properly. I was "sure" that the gimbal is balanced.. and it wasn't of course.
It is not a cogging problem - I used various motors in my gimbals (3506, 3508, 4008), versions with both 14 and 24 poles, made by TMotor, GBM and LD-Power. I could always tune the gimbal to perfection: wherever I left it, it stayed there. There was nothing like that type of movement I could see the video above. Look at the second 11 - this is WRONG. It stays completely off level on roll axis when the camera is pitched down.

You can't say "as long as it is perfectly balanced, it will work", mine is perfectly balanced and it still vibrates. Well I'm not going to argue about it, life's too short and so is that video to really judge if it is balanced adequately or not.

Anyway, you have a Z15 because you wasted enought time on other crap - so I guess you never got them working.

 

[wm1]

Looks like there is no cure for the wobbles/vibrations when you tilt the 3 axis alexmos gimbal down beyond 35 to 40 degrees when in 'fixed' mode, which is how it would need to be if used for filming from a UAV. The only I believe is to wait for the NEW Alexmos 3-Axis stabilised controller to appear. Or of course you can buy a Z15 at an extortionate price.

See this thread for info:http://forum.basecamelectronics.com/index.php?p=/discussion/560/yaw-roll-combination-oscillation