Hi all! I've exhausted all other avenues of diagnosing this issue. 5" iFlight Nazgul, it's been in many crashes so the FC and ESC have been swapped out long ago. This has been a very annoying issue where when I throttle up, initially it would pitch slightly up and yaw slightly right. Thinking it was a gyro issue (MPU-6000) I replaced the gyro. Same outcome for test flight after that. I have since flashed Bluejay 0.19 from 0.20 as I never knew it had been pulled due to ESC-related issues that could happen. Now the issue has turned to a yaw left when throttling up (not directly after replacing gyro), but seemingly from going to Bluejay 0.19 and changing PWM to 48 from 24.

I'll attach a blackbox log below, but I have a lot of yaw noise coming through the gyro. Things I've tried:

• Set Betaflight settings to default.
  
• Set ESC settings to default, change versions from Bluejay 0.20 to 0.19.
  
• New props.
  
• Tightened arm screws slightly, none were loose.
  
• Loosened FC nuts, I mistakenly had a couple too tight.
  
• Re-routed camera wire away from gyro
  
• Verified it is NOT a camera mount issue.
  
• Change filtering settings
  
• Replaced MPU-6000 gyro
  
• Checked RC Command in blackbox log, no yaw input.
  

This only occurs during throttle up, whether it is blipped or the throttle is increased over time.

I do not have another ESC or gate driver ICs to replace on the ESC to quickly check if it's the issue.

Gyro roll (filtered)


Gyro yaw (filtered)


Blackbox log, attaching the file in the post wasn't working!
https://drive.google.com/file/d/1gjwp4QD...sp=sharing

You did not say what airmode you are flying. If you fly in Angle mode, the gyro comes into play. If you fly in Air or Acro mode, the gyro (I believe) is not in the picture.

Are you referring to tiny yaw twitching? I don't see any significant yaw movement in your log when you pump the throttle. There is some yaw oscillation/twitching, but it doesn't seem to be much. Is your FC mounted firmly and you have nuts holding the mounting screws tight to the bottom plate? You should be able to move the FC when you compress the gummies, but otherwise there should be barely any movement with shaking or twisting. If it is twitching you are seeing, then double check frame/arms are not delaminated or have damage and motors still running smoothly.

Also from your log, all your throttle pumps have the rear motors working slightly harder, not related to yaw but you might want to slide your battery forward a little for better CG.

(12-Jan-2024, 05:56 AM)mstc Wrote: Are you referring to tiny yaw twitching? I don't see any significant yaw movement in your log when you pump the throttle. There is some yaw oscillation/twitching, but it doesn't seem to be much.

This video shows blackbox log between 0:23 - 0:30.

Here's a side shot of the quad. Everything is solid.

Maybe you posted a different log as I did not see that movement at 23-30s. However if you look at 30-37s and show your RC Command yaw, you can see every time you raise your throttle you are adding yaw to the right (bold red in screenshot). This would be consistent with the type of behavior you are showing in the video, but in the other direction. 

If you are having trouble throttling up without applying some yaw, either try using the pinch or hybrid pitch method on the sticks (assuming of course that you are currently using the thumbing method to control the sticks), or you can try adding a small amount of deadband to the yaw axis which will cause any slight movement either side of the centre point to be ignored. You can use the yaw_deadband CLI setting to do that.

(13-Jan-2024, 01:25 AM)mstc Wrote: Maybe you posted a different log as I did not see that movement at 23-30s. However if you look at 30-37s and show your RC Command yaw, you can see every time you raise your throttle you are adding yaw to the right (bold red in screenshot). This would be consistent with the type of behavior you are showing in the video, but in the other direction. 



Man there's no way I'm this stupid. I swear I checked my logs for RC Command and it was always zero movement.. I'm wondering now if I fixed my previous problem (it would pitch up + yaw right slightly on throttle up, I 100% verified log to having no RC Command) replacing my gyro but betaflight somehow at some time reset every setting to defaults including my deadbands and I never caught it until after logging without realizing.

Tomorrow I'm going to do another test flight to see and will report back.

This was my very initial issue over the summer that I didn't fly most of the summer due to being unable to film with the GoPro due to stabilization having a lot of blurriness whenever I'd throttle up. I replaced my gyro (MPU-6000) and now I can't recall if it was still present or if that's when the yaw starting moving left albeit a lot more... Lol.

Is the quad in the video on acro mode? It almost seems like it's on angle mode and trying to self level

Woo! Must be an ESC issue after all. Went to do a test flight after installing BF 4.5 for motor RPM in logs and my first arm had a major yaw spin. Disarmed then re-armed and motor #2 was acting very funky. Seems like a phase is missing for that motor. Brought it inside to diagnose, removed props and tested each motor in motors tab of BF and found #2 to resume acting funky and then magic smoke! Couldn't figure out where it came from exactly but now no more magic smoke and I have a video to show what she's doing. Unsure if it's mosfet/gate driver or MCU for that motor.

Just reading through this thread and checking the videos, the first think I thought of, that's a motor issue.

Easy testing technic I have found flash Bluejay 96Mhz to your ESCs --  test again -- if motor or ESC for sure the issue will be worse, then flash Bluejay 24Mhz, then problem might even seem to have disappear, but your quad will fly like rubbish, and appear not to be tuneable. Method to find out if motor or ESC, swap 2 motors about, and test motors again if the problem has swapped position it's the motor, if the problem is in the same position it's the ESC.

I had this problem with a brand new build with new motors https://intofpv.com/t-ack80-attack-chick...otor-issue and I used this technic to work out what is going on.

Hopefully you will soon nail down the issues, and be flying a great quad.

Cheers

(17-Jan-2024, 06:41 AM)Cyberess Wrote: Just reading through this thread and checking the videos, the first think I thought of, that's a motor issue.

Easy testing technic I have found flash Bluejay 96Mhz to your ESCs --  test again -- if motor or ESC for sure the issue will be worse, then flash Bluejay 24Mhz, then problem might even seem to have disappear, but your quad will fly like rubbish, and appear not to be tuneable. Method to find out if motor or ESC, swap 2 motors about, and test motors again if the problem has swapped position it's the motor, if the problem is in the same position it's the ESC.

I had this problem with a brand new build with new motors https://intofpv.com/t-ack80-attack-chick...otor-issue and I used this technic to work out what is going on.

Hopefully you will soon nail down the issues, and be flying a great quad.

Cheers

Oh the MCU or Gate Driver committed unalive. Unsure the methods to diagnose an esc mcu / gate driver issue but 3 motors work fine except for one other. Going to re-order an ESC and keep this one as a backup. Probably going to order some MCUs and Gate Drivers for a cheap fix too.