Vibrations according to the Spectrum analyser (Spirit GTR defect?)

[Manni]

Hello,
I fly a SAB Kraken 580 with 6S with the Spirit GTR (Firmware 3.7.4). The helicopter is flying perfectly.

However, according to the spectrum analyser, the helicopter has increased vibrations, particularly on the x-axis. The cause is believed to be the tail rotor. All attempts to reduce the vibrations were unsuccessful. But I noticed, according to the Spectrum analyser, that the vibrations decrease significantly (= ‘OK’) when I press the servo plugs gently towards the Spirit GTR.

Does that mean the Spirit GTR is defect?

I would be very grateful for any advice.
Manny greetings

Manni

[ZeXx86]

Hello,

if you push the spirit unit then you are also dampening vibrations significantly, because your force is deamplifying a motion. In any case make sure that cables are not vibrating and holding well, not touching the unit from other side than connectors.

[senaka]

I have the same heli and "had" the same issue as yours - bad tail vibrations. I ultimately had to weigh every nut, bolt changed every bearing, shaft, tail blades ..... and found that the blade holders were not balanced (different weights) after balancing them, it's now OK. Also place the heli on some carpet during the tests and not on a hard floor.

[Manni]

Hello Senaka,
thank you for the tip. How did you compensate for the weight difference in the blade holders?

Many greetings

manni

[senaka]

Hi manni

I removed some material from the heavier one equally on both sides as attached. Slowly drill it out. I tried slow curing epoxy drops as weights but that kept on falling off. I’m not sure if I did correct thing. Potentially now it’s dynamically off balance. But the vibes are lower

[Manni]

Hello Senaka,
thanks for the tip. I'll check to see if I have the same problem and look for a solution.

Manny Greetings

Manni