OK Turbine Gurus......

[lperagallo]

I have a Bergen Turbine. It flys great! What is odd is that each day when I do my first flight I normally have to adjust the middle point in my throttle curve to get it the vibrations out. Same thing in Idle1. Not much mind you, 1 or 1.5% on the middle point either up or down. The effect on head speed is around 150-250 RPM. Blade tracking looks OK as far as I can tell.

Does anyone know what causes this? Do others experience this? What should I be looking for in the mechanics to see if something is off balance? I run Vblade 810's with a head speed of around 1,400 in normal and 1,610 in Idle1. A couple of times the vibration became less if I jerked the heli up and down a few times with hard collective.

Not that it's much of a pain, but I'd like to figure out if I've got something out of line.

Help is appreciated,
Lou

[rkeith2]

Lou -

1450 and 1650 respectively is what works best for me and I also found that I needed to be extremely exact on flybar centering.

I also had found after a slight mishap with terra firma that one of my blade holder arms was bent slightly -

All is good now.

[Coolice]

Hey,

This model is still quite new isn't it? If so I'm more inclined to say the head dampers are perhaps still wearing in, hence the slight vibes at certain RPM's.
Just a thought.
.

[rkeith2]

The only time we see damper caused issues is when one of them is squeezing through the holding collar and is easy to spot -

Lou, you may want to inspect both sides of the head axle area closely for that.

[lperagallo]

I can see a part of the Oring peeking through the head block on both my Turbine and Gasser. What's the best way to keep them in place. I only have the thick shim in place, no others. Is there a good way to get the circlip on when using the other shims? Is it possible to put one side on and then just bolt up the other end on the head axle to get the circlip on?

[rkeith2]

Whenever I see an o ring pinching out I pull it apart and replace at the very least that one that is in question. I lube the axle and rings and place one clip on.

I use a single thick washer on each side and have created a tube that is the right tool for the job to compress the other into position.

I generally get quite a bit of flight time between this happening -

You may want to reach out to Chris D. Bergen and see if he has thoughts on it.

Ron