Gimbal shaking

[bulesz]

Heyho,

I am stacked with my board, it';s a RCTimer Martinez board with Alexmos 2.2b on it.
https://www.youtube.com/watch?v=vz60QXBqj1Y

I can';t imagine what could be wrong because I did the acc and gyro calib, the indicators show the right roll and pitch axis, when I move the roll and pitch they moving to the right direction.

When powering up it is shaking mad and don';t want to level....

Any idea would be nice!

At the end of the video you can see my basic settings.

Many thanks,
B

EDIT: tried with 12V, was the same...

[The.Quadfather]

is the IMU orientation correct ?
you probably have, but just checking!

do the motors respond correctly when not mounted on the gimbal ?

[bulesz]

Heyho,

Thanks for your reply!

The IMU orientation is correct (triple checked), thanks for the hint, I will try the motors alone, not mounted...

Cheerz,
B

[bulesz]

I just tried the motors unmounted, unfortunately I have got the same shaking result.

[graeme647]

I was doig exactly this for the first time last night (till about 4am!)...

Mine was the pitch axis which was going crazy, turned out I needed to change my Z to -Z as it thought it was upside down but looks like you';ve done that already on your X.

Anyway, after I';d finally got it sorted I started messing with PIDs, the one thing I noticed is that I could keep my pitch I at 0.4 for maximum response but my roll I couldnt be above 0.15 otherwise it reacted similar to yours, try dropping that down some, maybe start really low and and see if theres any impact.

As it';s changing direction it appears to be trying to over compensate.  I think I was pretty lucky, I seemed to set everything else up ok on first pass and it still took me 4 hrs on my first attempt, not perfect yet but I have control inputs from my TX working and it levels pretty well.

[bulesz]

Thanks for the reply, I have tried it with 0,1 I and it was the same shaking. Maybe the board is corrupted...

[graeme647]

Right then, I';ve tried to replicate the effect you';re getting, the only way I can do it is via IMU orientation, if I flip my axis the board tries to self correct but in the wrong way, compounding the error and confusing the board.

I know you';ve tried it 48 times already but apart from a corrupt board its the only thing I can imagine!

[bulesz]

Thanks mate for the input. How can I know the axis are wrong? I';m asking because if I';m moving the IMU, the ROLL and PITCH indicator is doing what it should (I mean the moving direction and speed is the same as I movint (rotating) the IMU.

?

[graeme647]

Sounds correct then, I';m a bit stumped, my tests just came to and end for the moment too as for some reason my gimbal just puffed one of my lipo cells, not sure how safe these balance connectors are, may wire direct instead.

The only other thing I can suggest is remove main power from the controller board and run from USB only, hold the gimbal level and steady then run the CALIB.ACC, just hold it till the lights stop flashing and the pitch and roll indicators go level on screen, then move the gimbal gently in each axis to ensure it shows smooth and steady on the screen, also make sure if the quad is facing you that the roll axis movement on screen is the opposite of the physical movement (as its facing you it should be reversed)...

Sorry, scraping the barrel here and don';t mean to insult your intelligence but the amount of times I';ve kicked myself over something so damn simple after looking at it for hours is unreal! 

[bulesz]

Nevermind bro...just came back from a test flight, I had modified the PIDs a bit, lowerig the RATE ROLL P with 0.1...and I was wondering whatta heck was going on the quad was wobbling like hell...ehhe...my stupidity...I was "lowering" the P from 0.1 to 0.9.. it should be 0.09 OK, I';m to tired because of this fkkin gimbal...So I know what have you mentioned...need to triple check, and just for sure check again... :)

I have tried the ONLY USB method and it shown a correct behavior of the indicator horizons.

After that plugged to the main power (4S). I have recognized another symptom:

The ROLL motor is shaking and rotating with the RCTimer motor, and rotating smoothly with the Tiger GB 2208 motor.
The PITCH is shaking only with both motors, I have put the same PID and power settings to both the ROLL and PITCH for the debugging.
I have attached the basic setting page.

so could we say is it the board then? 

[graeme647]

Just another thought, I';m guessing that during the earlier trials you didnt have any inputs from the flight controller or receiver attached?  Just to ensure there was nothing weird there.

I';m still a bit hesitant to think its the board but it certainly could be, you can pick a cheap one up on ebay for around £10, this is the one I';m using 251462095883

[bulesz]

Thaks for the ebay link, I was thnking about the same board, but it take ages to get here, so I have ordered a BGC 2.0 from a local guy.

No, nothing from the radio or FC was connected to it.

[Brian]

I';m having the same problems, the gimbal is spazzing out big time, all the time. I have the goodluckbuy one. Also the roll motor is nice and warm, sort of warm enough to melt steel and embarrass the sun!

Brian

[Gav]

Hard mount the IMU. Sorry not read all the posts maybe been suggested already?   Don';t mount with double sided foam.