High RPM's vibration on Logo 500se

[fasthonda450r]

In idle up 2 at 1250 RPM's my Logo 500se vibrates. The machine flys fine at 2000 rpm's, but at hight rpm's the bottom of the tail fin vibrates with a harmonic noise? I've replaced every shaft and bearing.
Would gear mesh or bad main blades cause a bad vibration? Bad enough to cause the belt to lossen? Any ideas would be appreciated..

Thanks

"Do you think it's the spark plug??"

[Bullfrog98]

What does the vibe analyser on the V-bar say?

Also if you are running carbon tail blades try switch back to the stock white plastic ones and see if you still get the tail fin vibrations.

[fasthonda450r]

These are taken with NO tail blades on.. hope this helps
thanks
NORMAL MODE


IDLE UP 1 Roughly 1850 RPM's


IDLE UP 2 Roughly 2250 RPM's

[fasthonda450r]

This shot is taken with new pair of SAB tail blades at 2250 RPM's. The blades where installed a little on the loose side, and the vibes seemed to get much better. Do the tail blades need to be run loose or on the tight side? Also how do the gear mesh vibes look ?
thanks

[IMG][/IMG]

[thefrog]

Are you running a governor? If so try turning down the gain. I had a tail vibe that was actually the governor gain. Another thing - how many flights does the heli have on it? My vibe/gov gain issue went away after 15 or so flights. A little strange, but true.

[fasthonda450r]

No not running in governor mode, and the tail control rod is disconected.
Any building tips on the carbon tail box? I have about 50 flights on it and getting ready to build a new tail box for it. Maybe somthing is tweeked ..