Main pulley not balanced?

[Yakuzigen]

Hi all, 

I just finished building my E7 and ran it up without the blades to check for vibrations and found quite a bit. I was able to zero in on the issue and found that my main pulley is not balanced. What I did was ran the helicopter with just the motor and pinion, everything was smooth. Then I attached the main shaft & gear, still smooth. But when I added the pulley only, without driving the tail, I found a noticeable difference in the amount of vibration that was present. I’ve also placed the pulley on a magnetic balancer and found that it’s not balanced. Is anyone experiencing this? My pulley is brand new and looks perfect.

Thanks

[Jean-Luc Bolduc]

is this on the v-bar vib analyser ?

[Kevin Feil]

Yak,

  If the 42T pulley is not supported as you are tightening the through bolt, you will get vertical wobble. So.... as you are tightening the bolt make sure you are supporting the pulley but not putting any vertical load on the pulley. Please see illustrations and related videos. Notice B runs completely true but A and C have wobble.

A. Hold the main shaft, tightening the screws. A video can be seen from the slight swing 42T.
B. Hold 42T, tightening the screws.  you can see from the B video did not swing 42T.
C. Like the picture C, the 42T side to put some force (F), tightening the screws. As you can see from the video C 42T serious swing.

Bare with me, I am trying to download the Vid's. But untill then it's not that the Pulley is warped it's the way it is being tightened.

Kevin

[Yakuzigen]

Thank you for the response guys. I am using a beastx and doing everything by feel, but the amount of vibration I am experiencing is very noticeable, even without the analyzer. I will try to tighten the screw as recommended and will check back for the videos.

Cheers