BCX Vibration Issue

[bnwhtlw]

I searched gang but I cant find a definite answer to my problem.

I got a BCX last night and it took one bad spill that resulted in broken rotor went bought new ones, replaced on the broken one. The replacements are carbon copies right of the stock ones?

Anyway it took one other smaller spill that bent the flybar a little. I bent it back into line. But now I notice (and I think it was there before, but its seems worse now) a vibration. As soon as I throttle the whole rear of the Heli shakes.

I made sure that the upper rotor was tracking correctly. It still seems a little off but I have no more adjustement in my linkage. It seems to go away when I do a low throttle yaw in the direction that stops the upper rotor...so I know (I think I know) that its up there. Nothing seems broken and as far as I can tell nothing seems out of alignment. Im a noob to Helis and now I wish I had saved my money and gotten a dragonfly 5-5 or something.

Anyway, can someone point me in the right direction.
Thanx and Im sorry if this is answered somewhere obvious, I did searched, but maybe I missed it. Thanx and heres to my first post.

[Neon_Dave]

Welcome to the forums! :)

Based on what I can gather, it would seem the problem lies in either the flybar or another bent part in the rotor head system itself - the only thing that could possibly make the heli vibrate.

In the "spill", the flybar may have been moved on impact, by however little, which would cause the heli to vibrate; meaning there is not an equal amount of flybar on either side.

It's also possible that that bend in the flybar may be causing the problem. A little bend will cause an imbalance and also cause your rotor head to vibrate.

Try looking at those two things, I think that it may very well be the culprit of the vibration :wave:
-Dave

[rocknbil]

In addition to that there's also one other thing.

Always replace the blades in PAIRS, not just one. Look at the underside (or is it upper side) at the base of the blades, you wil see a tiny number etched in the plastic, this is the mold number. It will be a 1, 2, 3, or 4. Make sure the mold numbers match, while some have been able to mix and match these usually if you mix them up it will cause hella vibration.

The other thing is if the set screw in the bottom gear is not perfectly set on the slot on the shaft it can cause vibration. Usually it just slips and the CX does this "hop" thing, but it can slip sporadically and cause vibration.

[z-man280]

mine did the same thing after inverted flight. ( yup, inverted, as it went STRAIGHT to the floor!). i replaced all 4 blades, outer and inner shafts/gears, lower head, everything but the swashplate, and i STILL have a bit of fibration in my tail. as i throttle up tho, is settles down, and it flies just fine.

[Swanky Pants]

Stupid question, but does it vibrate left & right or front/back? I would imagine that would help diagnose what's going on.