HELP! weird "flip of death" type issue

ctFlyer

New member
I built a quad and it fly's amazing... almost.
sMy quad freaks out when I give it sharp stick commands on the roll or pitch axis. It will do a flip of death style flipout, every time I give it sharp commands such as a flip or roll. My motor idle speed is at 5, and I don't think this is a desync, because different motors will do different things each time. From my understanding of the blackbox logs, the two motors that should spin up to start the flip or roll do, but they go to full power, and then all the motors will shut off completely for a bit ignoring all giro input and RC Command, then spin back up by themselves and stoping the flip or roll. It happens in any direction, always the same way i initiate the flip or roll.

My setup:
Betaflight F4 running 3.2.4
Armattan 30A esc's running d-shot 600
Mr.Steele motors.
8k/8k
Dynamic notch filtering on
Antigravity mode on.
(let me know if you need more info)

blackbox logs (google drive link)
check the second log for a good example of the flips, but most of them have it too.

https://drive.google.com/open?id=1WUmrEfaWEepZxlyv3_wVugcx-PXxgpzi

Any help is greatly appreciated,
Carter
 

PsyBorg

Wake up! Time to fly!
Too many details are lacking mate.

Did you go thru and properly tune the quad or did you cookie cutter the build and jump right to turning filters on and copying others set ups?
What pids are you using? What rates? What have you done to isolate the flight controller? Did you set up Air mode? Are you using throttle cut? What % processor usage do you have with all these fancy things turned on running 8k / 8k timings?
 

French

Construire Voler S'écraser Répéter
No offense Bill, but I think we can offer some suggestions of things to try based on the info provided. A BF F4 can certainly handle 8K/8K.

If it’s doing a flip of death / one corner of the quad drops out, I’d check to make sure you don’t have a short between the motor wires and the frame. The easiest way to check is to put a digital multi meter in continuity mode, then put one lead on a motor screw and use the other one to test each motor wire on the ESCs.

If it’s “flipping out” and uncontrollably shooting into the air, you may want to check and see if you have any DMA conflicts in the CLI. I used to fly an Omnibus F4 board with dshot and blackbox, which would cause a flipping out issue.
See post 22 - http://forum.flitetest.com/showthre...w-5-quot-build&p=345473&viewfull=1#post345473
 
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ctFlyer

New member
Thanks for the responses guys:)
I have built a few quads before, so I feel like I have everything soldered correctly and what not. I did tune this quad properly, however it was a bit hard because every-time I wanted to do a sharp move to check for bounce back, it would flip out of the air. I have custom rates, but that should't affect the death rolls. I also have custom filters on, but it will do death rolls regardless of what the filter settings are at. I just checked for shorts in the frame, and did not find any. The weird part is that I can fly fine, as long as i'm flying smooth(Ledrib style) but as soon as I do a quick flip or roll, the quad flips out of control for a bit (5 flips ish), then catches its self. I am running airmode on. and have stock betaflight 3.2.4 pids, with D term boosted 5 on pitch and roll. if you would like, i can post a CLI Dump.
Don't forget to checkout my blackbox logs if you have not already.
Thanks,
Carter
 

cranialrectosis

Faster than a speeding face plant!
Mentor
I have seen this question before and IMO this could be vibe on the board or too high a P gain.

Any chance you can try soft mounting the FC or cutting your P gains by 50% (one or the other) and let us know if either works?
 

ctFlyer

New member
I have seen this question before and IMO this could be vibe on the board or too high a P gain.

Any chance you can try soft mounting the FC or cutting your P gains by 50% (one or the other) and let us know if either works?

The flight controller and motors are already soft mounted
 

makattack

Winter is coming
Moderator
Mentor
+1 on the P gains being too high, but that's just a huge guess based on the limited information we have.
 

cranialrectosis

Faster than a speeding face plant!
Mentor
If you are already soft mounted, just try cutting the P gains by 50% across the board. See if that helps.
 

ctFlyer

New member
No luck with cutting p gains, I kinda fixed it by disabling the accelerometer and dropping my rates way down, but that's not a permanent fix
 

PsyBorg

Wake up! Time to fly!
That points more to a vibration issue to me. I would check for bent motor shafts, missing magnets in motors, maybe check the mounting points for the FC make sure maybe a standoff has not broken, Make sure all the arm bolts are tight or all the bolts in the quad for that matter. Make sure your video camera is secure and not vibrating or bouncing on the frame, same with antenna mountings.
 

ctFlyer

New member
Yeah, I thought about that, but black box shows no abnormal vibrations, and the quad flies fine, as long as I'm not doing sharp moves
 

PsyBorg

Wake up! Time to fly!
Well that exhausts any ideas I have to help. maybe someone else has other ideas. Good luck figuring this out mate.
 

makattack

Winter is coming
Moderator
Mentor
What's your failsafe setting? I wonder if by doing the extreme maneuvers, the RX is losing connection with your TX. What RF/radio system are you using? Does it have RSSI telemetry back to your TX?
 

ctFlyer

New member
I'm using a flysky i6 and I have rssi in my goggles, and I have not seen any drop in rssi. I have stock betaflight failsafe settings too
 

KBTalon17

RotorBoyFPV
Im having the same problem with one of my new racers, except it only goes out of control when I do a front or back flip. the weird thing is it acts like its losing connection but then I can usually regain control.
 

ctFlyer

New member
Yeah, it sounds like we are having very similar issues, I've made some progress by disabling the accelerometer and turning my rates down, but it's not a permanent fix. Let me know if you figure out how to fix it.