something bad could be the carbon and how its cutted, all on roll sounds in this direction.
is the cut direction proofed? the carbon qualoty good?
do you feel much difference iff you ad some force by hand?

So today I tested these modifications with the 660mAh battery that I have been flying with since the beginning of testing:
- 100uF cap on 5V power rail, no improvement,
- I took off the battery strap, it was touching the bottom of the AIO, so I was worried about possible resonances transferred from the frame, I replaced it with adhesive tape, which I used to attach the battery to the frame so that the AIO only touches the frame through the gummies, no improvement,
- I was worried that the antenna was resonating, so I bent it and taped it firmly to the frame, no improvement,
- I significantly tightened the nuts on the screws that hold the AIO, no improvement,

Next, I tried the same thing with a 900mAh battery, which is a bit heavier. Propwash is even worse.

That's it for today, another two hours lost.

(24-Oct-2022, 01:52 PM)hugnosed_bat Wrote: something bad could be the carbon and how its cutted, all on roll sounds in this direction.
is the cut direction proofed?  the carbon qualoty good?
do you feel much difference iff you ad some force by hand?

I will inspect the frame later today evening ... But I didn't notice anything unusual before. The quality of the carbon is excellent.

The frame looks good, the direction of the fabric is fine, the bending strength of the arms is comparable.

Hey bud. I just saw your message, and I wish I'd seen this thread earlier. Your build looks great, and I'd be happy to help you get this thing flying perfectly. I have 3 of them built on the board you have right now, so our builds would be identical outside of the motors, so I'll start there.

Motors: Do you have bi-directional dshot and rpm filtering enabled? How many poles do you have configured? Most motors of that size have 12 poles, but the BH 1504.5 have 14 poles, so make sure that is configured correctly. 

Tune:

Make a backup of what you have (diff all) and save it somewhere. I found that there were a few changes needed from stock to make smaller builds fly a lot better. Copy and paste this in and see if this helps since this is the current tune I'm using:



Let me know if that helps or not. If not I'd love to get a copy of the blackbox log.

That was quick, I'm glad you're here.
Of course, bi-directional dshot is set, 12 poles. I will try your PIDs and settings tomorrow.

But, the fact that there is noise in gyro_scaled only on the Roll axis has nothing to do with how the PIDs are set. Do you have a gyro_scaled log somewhere where propwash was tested?

Did you see this post (#24) with blackbox logs? https://intofpv.com/t-3-5%E2%80%9D-scyth...#pid182019

(24-Oct-2022, 09:08 PM)MomoBrut Wrote: That was quick, I'm glad you're here.
Of course, bi-directional dshot is set, 12 poles. I will try your PIDs and settings tomorrow.

But, the fact that there is noise in gyro_scaled only on the Roll axis has nothing to do with how the PIDs are set. Do you have a gyro_scaled log somewhere where propwash was tested?

There is some resonance at about 500hz on the roll access, which you'd hit at about 30,000 RPM (500 RPS). The RPM filter handles this perfectly (since that's what it is designed to do) if its configured correctly. Having the wrong poles set would make it apply the filtering at the wrong frequency, so correcting that will hopefully solve your issue.

If it is around individual frequency (500 Hz), it can be filtered no problem, but my logs show broadband noise from 0 to 650 Hz, this can not be successfully filtered ...

(24-Oct-2022, 09:22 PM)MomoBrut Wrote: If it is around individual frequency (500 Hz), it can be filtered no problem, but my logs show broadband noise from 0 to 650 Hz, this can not be successfully filtered ...

Fix the motor pole configuration first and give it a try. The config I posted helps with low throttle stability and prop wash making the low-end feel a LOT more locked in (this applies to my previous 3"/3.5" builds as well). Give it a try.

By BBLogs I mean the raw file, not the diagrams. At this point I'd want to see a log after the changes.

Hmm, if you don't have the broadband noise there, the problem is mine, which is something I'd like to find out. And I know how motor noise looks like and I know how the rpm filter works. I don't need to explain that. Everything is clearly visible in that spectrum before and after rpm filtering and needs no further explanation... So, you have the broadband noise there or not? It is the one that is not dependent on rpm, it is constant over whole frequency range and independent on current rpm.

(24-Oct-2022, 09:25 PM)Recursion Wrote: Fix the motor pole configuration first and give it a try. The config I posted helps with low throttle stability and prop wash making the low-end feel a LOT more locked in (this applies to my previous 3"/3.5" builds as well). Give it a try.

By BBLogs I mean the raw file, not the diagrams. At this point I'd want to see a log after the changes.

There is nothing to fix about motor pole config, the Geprc GR1404 motor has 12 poles.

(24-Oct-2022, 09:33 PM)MomoBrut Wrote: Hmm, if you don't have the broadband noise there, the problem is mine, which is something I'd like to find out. And I know how motor noise looks like and I know how the rpm filter works. I don't need to explain that. Everything is clearly visible in that spectrum before and after rpm filtering and needs no further explanation... So, you have the broadband noise there or not? It is the one that is not dependent on rpm, it is constant over whole frequency range and independent on current rpm.

Pre-filtering there is noise on both the roll/pitch axis, which is on par with my 5" 6s Five33 Switchback using the same electronics (JHEMCU AIO and Naked Vista).

(24-Oct-2022, 09:38 PM)MomoBrut Wrote: There is nothing to fix about motor pole config, the Geprc GR1404 motor has 12 poles.

Very sorry. I'm not sure why I thought you had the BH1504.5 motors. Can you provide a blackbox log of a test flight I can take a look at?

Edit: Ahh it's because they look simular and Rob3ddd mentioned them in his post.

OK, it's very late here, hopefully it won't rain tomorrow and I'll try it.