Uncommanded pirouettes

[larghio]

Hi.

I have a few birds, and they all have spirits and fly pretty great.

I recently purchased a oxy4max kit and I am now tuning the spirit2.
It has kst 215 on cyclic and ms565 on tail
I have a 470LM with the same setup that flies great

Yesterday I got some scary weird behavior
With the tail gain on 38% piro consistency on 175 and revomix on 2. 3300rpm

when going full negativ to full stop I got several uncommanded clockwise pirouettes, that stopped when i clicked over to lower rpms. ie idle3 to idle 2
this was very scary and somewhat reprodusable. I tried reducing tail gain but problem persists.

The tail also kick out 90 degress clockwise when I land it too hard.

Any idees what could be wrong?
My 470lm with same hardware runs 40% gain, piro consistency 190 and revomix 4 on 3300rpm
and is pretty great

[larghio]

I recently changed from hobbywing 6a to a castle edge lite 75.

it passes the bec tester, but the logs show low voltage and reciever frame corruption

hmm

[TomazBernik]

Might be mechanical - tail belt slipping..

[larghio]

good tip, but in this case it turned out that it was the weak BEC in the castle ESC that made the reciever reboot due to brownout (not the fbl fortunately. thank you thomas)
As I want mah counting I installed an external bec and that solved the problem