Help! Mid-throttle Ocsillation on 5" Alien Full Kiss


New member
Hi everyone,

I'm in this hobby since 2 years.
Until now, I was focus on racing and have 4 drones on betaflight.
PID tuning and HD video was not very important for me.

I have recently build a drone based on Kiss more focus on freestyle.
I'm trying to tune the pid. It's the first time I try to modify the pid. I have read a lot of doc and watch many videos. But it's not a easy topic.
My other goal behind that is to have a nice/smooth hd footage.

Here is the details of the aircraft:
- Frame: Alien 5" slammed
- PDB: Impulce RC Mr Steele OSD/PDB
- FC: Kiss FC v2
- ESC: Kiss 32a (50v 220uf low esr capacitor on each esc)
- Motor: T-motor f40 pro v2 1750kv
- RX: Frsky R9MM
- VTX: TBS Unify pro32 hv
- camera: Foxeer Falkor
- hd camera: gopro session 4
- Lipo: Tattu 1050mah 95c / Tattu 1300mah 75c
- Props: gemfan windancer 5x4.3x3

I have mid throttle oscillations causing bad jello effect on hd footage.
These oscillations can not be seen on dvr but I can definitely hear it.
They are located between 36% and 45% throttle.

The FC runs at 1khz loop time, adaptive filter, dshot600. LPF and Notch are off.
If I set the LPF to High, there is almost no difference.
With default pids, motors are warm but not hot.

I have try the settings given by PsyBorg on another post:
Set Failsafe time to 0 seconds
Set P gains to R=4 P=6 Y=8.5 Set I gains to R=.04 P=.04 Y=.05 and set D gains to R=10 P=10 Y=0.
Set the TPA curve to be flat 0 til 55% then make a straight line to 100%
Set the TPA strength to .25 .2 .4

With these pids, oscillations are still there and the motors become very hot (it's summer and it's very hot outside. 35°C).
I have try different pid, without luck.

I'm out of idea on how to solve this.
If you have any ideas or experience on how to solve this, I will be glad to try.

Thank you.


New member
Just a quick update:
I raised I gains to R=.055 P=.063 Y=.055 because it was a bit loose to me.
I lowered P gain for yaw at 5,7 and raised D gain from 0 to 2,85.

Ocsillations are almost gone but the motors are still very hot.
If I activate notch filters, the motors run more cooler but it's change nothing to the oscillations.

I will try to play with the TPA curve to help the motors temperature.