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Vibration Analysis
https://www.spirit-system.com/phpBB3/viewtopic.php?f=20&t=4132		 Page 1 of 1
Author:  Jackson.Munich [ Tue 07. Jul 2020 20:59:04 ]
Post subject:  Vibration Analysis
I have use the SPIRIT 2 to do vibration analysis on the Trex450 with main and heck blades instralled (main rotor speed ca 2000rpm).
screenshots (over the WIFI-Link) are attached.

could someone tell me, what means this vibration?
what could happen?

is this too much vibration?
(in the manual, the analysis is done without main and heck blades.)

thanks a lot!

Attachments:
File comment: Z-Vibration : not ok?
z-vibration.jpg
z-vibration.jpg [ 125.19 KiB | Viewed 243 times ]
File comment: X-Vibration : acceptable?
x-vibration.jpg
x-vibration.jpg [ 126.12 KiB | Viewed 243 times ]
File comment: Y - Vibration : extremely bad? what may happen? SPIRIT 2 will lost control?
Y-vibration.jpg
Y-vibration.jpg [ 134.82 KiB | Viewed 243 times ]
Author:  Kluftinger [ Tue 07. Jul 2020 21:31:25 ]
Post subject:  Re: Vibration Analysis
Hi Jackson,

I usually measure the Y-axis since it showes the worse vibes (also in your case)
The data with blades and 0-pitch on the ground and hovering in the air are pretty much the same.
I use an extra channel and a switch on the tx to take a measurement, when I think everything is in the same condition as last time.

Up to a value of 50 the software says "OK", 51 to 99 is "Raised"
I startet doing vibe tests on a heli, that seem to have a weird acting spirit system.
The Y-axis showed 160 and the root cause was a swash plate (brand new!) with 0,4 mm to large bore relative to the shaft diameter.

So far I tested 7 more helis (360 up to 550 size)
3 of them where around 40-50, the other 4 where at 60-70 in average.
If the Y-axis is above 90, the mechanic has some serious problem.

If you do tests in steps of 50 rpm head speed, you can find the perfect rpm for your blades.
Author:  Jackson.Munich [ Thu 09. Jul 2020 23:07:32 ]
Post subject:  Re: Vibration Analysis
Hallo Kluftinger,
thanks for explaination. :D

case 1:
i hade done a test without the main and tail blades, (still with the flybar and the rotor blade holders), full throttle, main rotor speed ca. 3800rpm .
i got 130-160 extrem vibration.

something is wrong in the mechanics, right?

Case 2:
without blades, with out flybar, without main rotor head, only keep the swashplate, main rotor speed ca. 2600rpm
the vibration looks ok?
how about the tail vibration? too strong?
i have touch the tail rod, it vibration a little bit strong, just my feeling.

Attachments:
File comment: Y Vibration, without blades, with out flybar, without main rotor head, only keep the swashplate, main rotor speed ca. 2600rpm
y-axis vibration without blades and without rotor head, at2600rpm.png
y-axis vibration without blades and without rotor head, at2600rpm.png [ 49.83 KiB | Viewed 151 times ]
File comment: Y Vibration, without blades, with flybar, main rotor speed ca. 3800rpm
y-axis vibration without blades at 3800rpm.png
y-axis vibration without blades at 3800rpm.png [ 95.48 KiB | Viewed 151 times ]
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