Hello guys i'll keep it short,

I didn't really want to make this post but i can't figure it out on my own. I have a 5inch which i'm using mainly as a winter drone but it had annoying vibrations, they do seem throttle depend. I decided I would try to get rid of them so i got new props, still there.
Before tuning i decided why not use the latest betaflight, and so updated from 4 to 4.2. Flashed my blheli_s esc's to JazzMaverick for rpm filtering. Set up rpm filtering using Bardwell's guide, Oscar and Voodoo's (https://www.#deletethis#youtube.com/watc...ring-setup).
Set up 4.2 via, Bardwell "must change this" video (https://www.#deletethis#youtube.com/watch?v=rhfOVJMxY7E). Then i followed the beginning of his 4.2 tuning vid (https://www.#deletethis#youtube.com/watc...Zts&t=692s). Went through Ronin's tuning guide, looked through uav tech's tuning guide but I don't hear anyone taking about vibrations.

To sum up basically, flashed bf 4.2, added rpm filters left Gyro RPM Filter default. Changed dynamic notch filter and did rest of the configuration then decided to start from there. Tweaked filters tested pids changes but can't seem to make the vibrations diminish. Using mamba f405 stack, 4s, 2450kv motors, 350g no battery and i don't use a gopro.


This is the video, dump (profile 1) and bb log and vid (only of the first fligth because i fell back to it):
  diffall.txt (Size: 2.99 KB / Downloads: 97) https://we.tl/t-rfDRvEUSWg

I have footage from before and vibrations were also there but not as bad.

Any other suggestions on what to try is very much appreciated

what do you mean by vibrations?
if oscilations:
https://intofpv.com/t-pid-tuning-cheatsheet

(27-Jan-2021, 02:21 AM)hugnosed_bat Wrote: what do you mean by vibrations?
if oscilations:
https://intofpv.com/t-pid-tuning-cheatsheet

Thanks for your answer


I'm not sure if it falls under oscillations, looking at the bb I can see that the gyro follows the setpoint not too badly. On the dvr video, it is clearly visible though :https://we.tl/t-rfDRvEUSWg
I saw that thread but its from 3 years ago, do those tips still apply?

Your P is way too low. See the I term moving around during hard moves? It shouldn't move around that much unless it is super windy or you bonked a tree branch. The relatively slow oscillations in the video is not P term induced but I term induced. Your P is not enough so I term takes over. And actually your gyro is not tracking setpoint well as it overshoots in a lot of places - that is I term not being able to catch up. This is because the I term was never meant to do P's job so it doesn't correct properly and you see those overshoots. In contrast P term induced oscillations are much higher frequency shudder than the wobbly sort in your video.

I'd try bumping up your P to 1.5x your D and start from there moving up +5 on pitch and roll P until the slow oscillations go away.

Once you got the oscillations taken care of, bump up your pitch and roll feed forward to 150 and you will really see some good gyro tracking with overshoots only at the exit of the move.

It does look like oscillations but is it actually the quad or just the camera flapping around.

What sort of camera mounts do you use and do you have a soft mounted FC.

Maybe a few pictures would help as well as oscillations/vibrations can also be mechanical

(27-Jan-2021, 02:59 AM)the.ronin Wrote: Your P is way too low.  See the I term moving around during hard moves?  It shouldn't move around that much unless it is super windy or you bonked a tree branch.  The relatively slow oscillations in the video is not P term induced but I term induced.  Your P is not enough so I term takes over.  And actually your gyro is not tracking setpoint well as it overshoots in a lot of places - that is I term not being able to catch up.  This is because the I term was never meant to do P's job so it doesn't correct properly and you see those overshoots.  In contrast P term induced oscillations are much higher frequency shudder than the wobbly sort in your video.

I'd try bumping up your P to 1.5x your D and start from there moving up +5 on pitch and roll P until the slow oscillations go away.

Once you got the oscillations taken care of, bump up your pitch and roll feed forward to 150 and you will really see some good gyro tracking with overshoots only at the exit of the move.

Thanks for your response!

Hmm, now that you say that, you'r right. The gyro for the roll is all over the place on closer inspection.
I will retry with your recommended adjustments tomorrow, thanks.


Am i correct in asuming that what is happening is that because of the low I term, it is never able to catch up the setpoint, and as such keeps oscilating to get there? Is something it something like this but happening constantly?


Looking back sometimes the tracking is horrendous

I do have a question though, when i do those adjustements, is still a good idea to keep using the sliders or should i just change the values manually myself?

While i have you here, i would also obviously thank you Ronin for your guide Very nice work

(27-Jan-2021, 03:04 AM)UrbanJungle1966 Wrote: It does look like oscillations but is it actually the quad or just the camera flapping around.

What sort of camera mounts do you use and do you have a soft mounted FC.

Maybe a few pictures would help as well as oscillations/vibrations can also be mechanical

Pretty sure it's the quad as the oscillations (as i can now call them ) have differed slightly from version to version and between setup. The camera is mounted with a plastic bracket to a metal piece linked to the frame, i doubt it would be the camera it feels pretty sturdy from the outside. FC is soft mounted using nylon standoffs then rubber o rings. I will gladly post a few pictures but i must warn you, it was lost for a few months and has seen better days. It really is earning the name Lawnmower.

No, because of your low *P* term, your I term is taking over. Whether or not that I term is too high is hard to tell since your P term is too low. Thanks for the feedback! Pages 7-8 show what I term looks like under a proper P/D with hard moves and when bouncing against the ground. That should really illustrate the point of I term's job.

[edit] I'd just change the values by yourself instead of using the sliders.