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Nitrospazzz
10-05-2006, 04:27 PM
I had a tip over a few weeks ago at pretty low rotor rpm. Replaced flybar and did a test spoolup. The blades were horribly out of track (few inches) so I put in a new spindle and test flew it the other day. Blades a bit out of track but had the tail box rotate on me before I could track them in. Re-drilled and tapped the tail gearbox to 4mm so it won't rotate on me again and test flew it today after waiting way too long on tail blades.

Bad vib because the blades were out of track, got them tracking perfect now. But there is a horrible vibration, the whole heli shakes violently, its just a big blur. The tail and main blades are tracking good. The main blades look smooth in flight while the rest of the heli is shaking like mad. Is there something I should look for in the tail or elsewhere that would cause this bad of vibrations? I have a big AP shoot this weekend lined up but theres no way I could or would want to put a camera on it right now, vibrations just too bad.

Some things I have thought of and a few I have checked:
Blade balance - checked main and tail they are spot on
Tail gear mesh - it seems to rotate easily, might be this
Clutch and Clutchbell - had to mess with this after the crash, not sure how perfect it must be aligned

Can't really think of anything else.

PaulH
10-05-2006, 04:56 PM
It sounds like your main shaft is bent. If you were messing with the clutch, you might want to re-do the dial indicating of the hub, just to eliminate that as a concern.

Nitrospazzz
10-05-2006, 05:04 PM
Crap thats not good, thats what I was thinking but didn't think that would happen from a simple tipover. I think I'll pull that now and see what it looks like.

Puts a bit of a kink in the plans for a saturday shoot. Dang tailblades took too long to get here

Gary Travis
10-05-2006, 05:07 PM
No doubt in the main shaft, I'm sure you will find it bent.
Gary

Nitrospazzz
10-05-2006, 05:16 PM
Yup good call guys...boy I feel stupid for not checking that when I pulled the spindle to check it:arggg: (insert colorful language here) ya...ok easy fix time to call Bergen and see if I can get one here by tomorrow.

And wow was that thing bent, a good 1/8 inch or so


Guess instead of spending all day flying like I planned I should study for that econ test tomorrow...although I want to try that new firmware for the AP2000i :mrgreen: