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

Posted: Wed 03. Jun 2026 17:05:51
by 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

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

Posted: Mon 08. Jun 2026 13:26:56
by 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.

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

Posted: Tue 09. Jun 2026 16:57:28
by 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) :shock: after balancing them, it's now OK. Also place the heli on some carpet during the tests and not on a hard floor.

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

Posted: Wed 10. Jun 2026 8:59:13
by Manni
Hello Senaka,
thank you for the tip. How did you compensate for the weight difference in the blade holders?

Many greetings

manni

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

Posted: Wed 10. Jun 2026 15:39:47
by 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

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

Posted: Wed 10. Jun 2026 15:55:43
by 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