vibration help on my fusion 50

[elvina gate]

im having very bad vibration on my fusion 50, im running 2150 rpm, 12t pinion and 129 main gear, drive gear ratio 1:10.75:4.58, running on 12s 2x 3300, log 91 and 92 are vibration log, log 88 is playback log, help is appreciated, thanks

[georgi UK]

=] hi, yes it's tail RPM's. output shaft bent comes to mind? can't open the playback log, sorry!

[elvina gate]

i check the tail shaft, it was not bend, try to align everything on the tail, still getting vibration

[Tomstoy2]

Just checking here, have you first tried moving the 720 to a different location and different mounting foams to get the lowest vib reading possible, first?
If not, do that first, then once that is done you can start troubleshooting the vibs. Otherwise it's defeatest.

[georgi UK]

=] ok, need to ask if the vibe is new because of a re-build or something?? in 3D its showing a revolving tail axis that is not running centred or true.

if the units position was good before we need to locate the issue as the cure. run the vibe logging by removing parts as you go to eliminate the cause on the deck, blades off being the most important.

[elvina gate]

the vibe is new, the heli has been rebuild, i change all the main bearings, but not on the tai, the tail shaft is new, the unit was mount at the same position before i rebuild the heli and i have no vibration problem that time, im suspecting it was my tail blade that causing the vibration, im using the new fusono plastic tail blade,

i uploaded vibration log and playback log

[elvina gate]

i just try a quick test with no main blades and tail blades

[snowball75]

Based on that log and your previous tests, it's your tail blades. Are they balanced? Do you have another set of tail blades you can try. You're getting there.

[Luvmyhelis]

Either that or the holes in the grips are machined poorly. In essence, if one grip is drilled a few thousandth off center or out farther and the other is drilled in towards the hub closer. This was a huge issue I had to track down with several pairs of my grips here recently. But for sure I would take a super close look at your tail blades first. Also, you need to still pull the grip assembly and do a balance test on them by using the center hub hole and sliding them on a smaller or thinner horizontal shaft. When you tap on them they have to set exactly level when they settle down. I am still seeing a spike there without the blades. And you say your shaft is straight so this is all it can be.

[georgi UK]

=] for me its mechanical, a blade fix would surprise me here? can you run with the tail hub removed and view the output shaft, is there any movement in it?? touch it as its running, how does it feel?

[elvina gate]

The output shaft is new, i just tried to roll it on the glass it seems straight, one thing is when the heli is on the air you can hear the vibration noise, it seems its coming from tail blade bec. Its plastic and soft, as i see the spike on the log without the blade, im gonna change the output shaft and the all the bearings on the tail

[georgi UK]

=] the shaft may be good?, it could be the bearings allowing it to move is what I'm seeing, but the shaft is out and yes you will hear it!

[elvina gate]

i had a quick flight today , i only change the tail blade , no vibration warning, but i still seeing some spike, i dnt know if it was the tail or coming from another place, i uploaded the log, help on reading this log needed

thanks georgi and to the other guys that helpme resolve this vibe, i have all the tail parts, so probably i gonna change what ever i need to change on the tail

[georgi UK]

=] yes it's the same vibe on a lesser scale than the original one posted, blades have helped here but there is still a need to strip the tail and inspect its parts.

previous logs were showing the same pattern at different magnitudes, blades on blades off =


the last log is showing this same vibe composition =



its going well, so keep at it!