Gimble shake

John235 · Mar 2, 2019

Problem?
Gimble shake on takeoff. At Auto takeoff with precision landing the gimble shakes as AC ascends and for a few seconds after it begins to hover. Yesterday I also got a gimble shake warning. The shake then stops and does not seem to return during the flight. At least I have not gotten any other warnings or had it affect fpv or recording. Wondering if I need to adjust vertical gain. Perhaps shake is caused by over correcting vertically after rapid jerk of takeoff. Note below that I have low noise props with other gains adjusted.

Was unit in a crash?
No

What have you tried so far?
Nothing - was planning to test adjusting vertical gain and Auto takeoff, but waiting for good weather to spend in multiple takeoff tests.

What device are you using ( iphone , ipad, Samsung , etc)?
Ellipsis tablet

What firmware are you running ( aircraft, remote controller)?
Not sure. Could it affect this issue? If so, I will get it.

What Go app version are you using?
At the time, go 4 version 11, now have version 14, but have not flown since that update

Any modification? (if so what)
No

Did you change anything or install any apps? (if so what)
Yes. MPP low noise props (gold tips) installed. Gains on all but vertical set to 89. Vertical left at 100.

Do you have a video or pictures of the problem? (if so post link)
no

brett8883 · Mar 3, 2019

John235 said:
Problem?
Gimble shake on takeoff. At Auto takeoff with precision landing the gimble shakes as AC ascends and for a few seconds after it begins to hover. Yesterday I also got a gimble shake warning. The shake then stops and does not seem to return during the flight. At least I have not gotten any other warnings or had it affect fpv or recording. Wondering if I need to adjust vertical gain. Perhaps shake is caused by over correcting vertically after rapid jerk of takeoff. Note below that I have low noise props with other gains adjusted.

Was unit in a crash?
No

What have you tried so far?
Nothing - was planning to test adjusting vertical gain and Auto takeoff, but waiting for good weather to spend in multiple takeoff tests.

What device are you using ( iphone , ipad, Samsung , etc)?
Ellipsis tablet

What firmware are you running ( aircraft, remote controller)?
Not sure. Could it affect this issue? If so, I will get it.

What Go app version are you using?
At the time, go 4 version 11, now have version 14, but have not flown since that update

Any modification? (if so what)
No

Did you change anything or install any apps? (if so what)
Yes. MPP low noise props (gold tips) installed. Gains on all but vertical set to 89. Vertical left at 100.

Do you have a video or pictures of the problem? (if so post link)
no

You have your gains backwards everything should be 100 except vertical which you can adjust down to 90 IF there’s an issue with having it at 100. There really shouldn’t be though.

Vertical gain is better discribed as “throttle gain” and it’s what is directly affected by the additional thrust of the MPP props. You could actually up your yaw gain to 110 if it’s difficult to get a smooth panning motion. Since the props are spinning at a lower speed they don’t have as much angular momentum therefore needs more gain not less.

John235 · Mar 3, 2019

From a previous threads, "What happened here?" And "Mavic Pro Gimble Freak Out"

I used this video,

This video helped me solve the shake, my original problem, I thought completely. However, this current shake at takeoff leads me to think that I did not go far enough. I am thinking the sudden jerk of an Auto takeoff may be throwing the gimble into a vertical over compensation oscillation.

John235 · Mar 9, 2019

Follow up on this problem:
Got to fly for the first time in many days. When I went to the gains, I found values of 87/87/89/100. I had set the 3 lateral gains to 89, after having tried 87, so I thought at first I had simply goofed. However, I discovered something strange. After setting the lateral gains all to 89 again, closing and then reopening the gain settings, the values were 87/89/89/100. As I watched, the first value changed to 88. It occurred to me it may take some time to "take." Next, I rest to 89/89/89/100 yet again, closed the window, waited a moment, then reopened the window to find the values had this time, held. Lesson: check your gain changes to make sure the in fact take effect.

Then, I worked on the vertical gain, and found that a value of 98 worked and removed the takeoff gimble shake. I will watch over upcoming flights to see if conditions such as wind gusts may cause the shake to manifest, and adjust accordingly.

Values used at present for my MPP gold tip quiet props:. 89/89/89/98.

Thanks to all for your tips.

elmosfire · Mar 10, 2019

John235 said:
Follow up on this problem:
Got to fly for the first time in many days. When I went to the gains, I found values of 87/87/89/100. I had set the 3 lateral gains to 89, after having tried 87, so I thought at first I had simply goofed. However, I discovered something strange. After setting the lateral gains all to 89 again, closing and then reopening the gain settings, the values were 87/89/89/100. As I watched, the first value changed to 88. It occurred to me it may take some time to "take." Next, I rest to 89/89/89/100 yet again, closed the window, waited a moment, then reopened the window to find the values had this time, held. Lesson: check your gain changes to make sure the in fact take effect.

Then, I worked on the vertical gain, and found that a value of 98 worked and removed the takeoff gimble shake. I will watch over upcoming flights to see if conditions such as wind gusts may cause the shake to manifest, and adjust accordingly.

Values used at present for my MPP gold tip quiet props:. 89/89/89/98.

Thanks to all for your tips.