tail vibration\bobbing

[cupracing]

yet another issue with the beam. everything is ok on normal mode when the headspeed is low but once in idle up the tail is vibrating/bobbing up and down, the belt tension seems ok and ive checked nothing is bent the gyro gain is also fine. could a worn belt cause this?

[jamiem]

worn dampers? when you say yet another problem, what other have you had? mines been good as gold so far as have many others i know of

[cupracing]

ok ive overreacted a bit I havent had too many problems but im forever setting it up rather than flying it (the setting up isnt going to well as you have guessed)
the dampers look fine and are still like new but how would this effect the tail? im running my throttle curve at 90% flat and a thought had crossed my mind that may be a frequency issue?

[cupracing]

I have the bigger bearing in mainshaft blocks at the top is this incorrect, im thinking maybe the belt if rubbing against the gear?

[jamiem]

not sure on the bearing. have yor tried a new pack if the batterys are getting tired? or just try changing the throttle cure by a few % either way as you may have hit a resonant point. what motor/pinion are you using?

[cupracing]

using the 14 tooth

[jamiem]

on what motor, and what lipos are you using and how old?

[cupracing]

scorpion hk-2221-8 motor and using 2200mah 25c zippys

[jamiem]

ok well try changing the throttle curve and see how you get on. bobbing up and down on the tail usually idicates shot damping, low headspeed or a head inbalance in my past experience. have you checked your main blades are balanced?

[dj propo]

if were you i would removed tail rotor hub and test on a high point balancer such as the dudro one with the blades fitted, with the head and tail speeds these little things are running you want the balance bang on the tail hub as well as mains

[cupracing]

well a done a bit of tinkering, things I did was change the bearing round so the belt ran lower on the gear and I suspected it was rubbing. tightening up the belt a bit just in case it was too slack. took the tail blades off ans checked the balance and made sure they were straight and true. I also lowered the gyro gain incase the headspeed was too much for it. Well soemthing I did seems to have fixed it so Im happy now. thanks for your helps chaps