Extreme Vibrations Readings in a 30cc Plane

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davehour
Posts: 134
Joined: Sat 30. Aug 2014 0:03:16

Hi,

I’m getting extreme vibrations in my 30cc Extra300LP. The readings are extreme in the elevator and aileron axis’, but higher in the rudder axis. Nevertheless, I activated rescue and didn’t see the gyro going crazy at idle or full throttle. As far as the vibrations of the model, I can tell they are normal.

One thing I noticed was the readings were about the same when engine was at idle or full throttle.

The Spirit is mounted in the recommended place per previous thread:

viewtopic.php?f=35&t=3031.

That place feels solid. I see no other good place to mount the unit other than the motor box which would be impractical for wiring reasons, plus being close to engine carb spills.

Attached are pictures of the readings and where the unit is mounted.

Thanks,

David
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davehour
Posts: 134
Joined: Sat 30. Aug 2014 0:03:16

Pictures
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ZeXx86
Site Admin
Posts: 12782
Joined: Mon 29. Apr 2013 16:06:44
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Hello,

with a gasser models it is relatively common.
But it is interesting that there are 3 spikes. This could mean that there are resonant frequencies. Or are there some gears? I guess that not.
Spirit System developer
davehour
Posts: 134
Joined: Sat 30. Aug 2014 0:03:16

Hi Tomás,

Am I ok to go?

No gears, just a wood prop.

Appreciate your support.

David
threeDfreak
Posts: 48
Joined: Mon 30. Oct 2017 19:18:22

it have a massive impact where you mount your Spirit. You must mount it as close as possible to the engine. Even if it cause new wiring. Also you must mount it as hard as possible to the plane. It should not "wiggle" arround. Do not use 2 or 3 pads over each other to mount you Spirit.

When you mount it at the middle of the plane far away from the engine you will have massive vibrations. When you mount direct next to the engine and on a hard surface you will see that everything is good.

That was my solution for the vibration problems on my Extra 330e.
davehour
Posts: 134
Joined: Sat 30. Aug 2014 0:03:16

threeDfreak wrote:it have a massive impact where you mount your Spirit. You must mount it as close as possible to the engine. Even if it cause new wiring. Also you must mount it as hard as possible to the plane. It should not "wiggle" arround. Do not use 2 or 3 pads over each other to mount you Spirit.

When you mount it at the middle of the plane far away from the engine you will have massive vibrations. When you mount direct next to the engine and on a hard surface you will see that everything is good.

That was my solution for the vibration problems on my Extra 330e.



Mounting the Spirit Pro there would be the ideal location in terms of a hard surface, but would also be an impractical mounting location for a gasser because of the fuel, heat and spark/ignition noise that can affect the electronics.

In your case, your plane is electric.
crackedcanopy
Posts: 13
Joined: Sat 20. Jun 2015 3:32:50

I have the same dilemma. I have the Spirit 2 mounted as shown - yet to fire her up so I don't know what the vibs are like.

current_position.jpg


I am wondering about moving it to here:

new_position.jpg


I would leave the RX where it is (Jeti EX link) but I don't know if extending the distance between FBL and RX is a good idea.

Suggestions welcomed. I had a JETI assist RX in a similar plane and that didn't go well due to vibs. I am hoping the Spirit 2 is more resiliant.
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