Twister vibration

[Tim Kearsley]

Hello all,

I'm a newcomer to R/C helicopters and recently bought a Twister
electric micro heli. I know that this is not the best route for a
beginner but I did it anyway! I am at the same time getting some time
in on the FMS simulator.

I've progressed a bit but am now experiencing a problem where the
model shakes quite badly just as it is about to lift off. It has
suffered a few collisions, as you might expect, and I am wondering
what I might have damaged.

I have checked the balance of the rotor blades and that seems fine.
The document that comes with the model suggests checking things like
the main rotor shaft isn't bent but I haven't a clue quite how you
would check that. It looks to me that one rotor is possibly tracking
slightly higher than the other - could this be the cause?

Any thoughts as to how I ought to proceed?

Many thanks.

Tim Kearsley

[Dave Yates]

The main blades must be at 90 degrees to the flybars or else that's more
than sufficient to cause vibration. Are the main blades loose (they
shouldn't be).

I've had to replace the main gear/shaft for the same reason - you might just
have to fork out five quid for the new bit. It's easy to change - just
remove the tiny metal pin from the rotorhead and it all pulls apart. The one
I took out looks fine, but is definitely bent.

I'm not sure how valid a test it is to check the pip on the very top of the
rotor whilst spinning the blades slowly (not too fast or the whole lot
thrashes about).

Dave Yates

"Tim Kearsley" <tim.kearsley@milton-keynes.gov.uk> wrote in message
news:725736ef.0411230535.43dab153@posting.google.c om...
> Hello all,
>
> I'm a newcomer to R/C helicopters and recently bought a Twister
> electric micro heli. I know that this is not the best route for a
> beginner but I did it anyway! I am at the same time getting some time
> in on the FMS simulator.
>
> I've progressed a bit but am now experiencing a problem where the
> model shakes quite badly just as it is about to lift off. It has
> suffered a few collisions, as you might expect, and I am wondering
> what I might have damaged.
>
> I have checked the balance of the rotor blades and that seems fine.
> The document that comes with the model suggests checking things like
> the main rotor shaft isn't bent but I haven't a clue quite how you
> would check that. It looks to me that one rotor is possibly tracking
> slightly higher than the other - could this be the cause?
>
> Any thoughts as to how I ought to proceed?
>
> Many thanks.
>
> Tim Kearsley

[Carl Farrington]

Tim Kearsley wrote:

> I have checked the balance of the rotor blades and that seems fine.
> The document that comes with the model suggests checking things like
> the main rotor shaft isn't bent but I haven't a clue quite how you
> would check that.

Try taking the shaft out and rolling it on a flat surface (peice of glass
perhaps). You'll soon know if it's straight or not

[NBA - LA]

"Dave Yates" <davidgyates@hotmail.com> wrote in message news:<41a35767$0$68688$ed2619ec@ptn-nntp-reader03.plus.net>...
> The main blades must be at 90 degrees to the flybars or else that's more
> than sufficient to cause vibration. Are the main blades loose (they
> shouldn't be).
>
> I've had to replace the main gear/shaft for the same reason - you might just
> have to fork out five quid for the new bit. It's easy to change - just
> remove the tiny metal pin from the rotorhead and it all pulls apart. The one
> I took out looks fine, but is definitely bent.
>
> I'm not sure how valid a test it is to check the pip on the very top of the
> rotor whilst spinning the blades slowly (not too fast or the whole lot
> thrashes about).
>
> Dave Yates
>
> "Tim Kearsley" <tim.kearsley@milton-keynes.gov.uk> wrote in message
> news:725736ef.0411230535.43dab153@posting.google.c om...
> > Hello all,
> >
> > I'm a newcomer to R/C helicopters and recently bought a Twister
> > electric micro heli. I know that this is not the best route for a
> > beginner but I did it anyway! I am at the same time getting some time
> > in on the FMS simulator.
> >
> > I've progressed a bit but am now experiencing a problem where the
> > model shakes quite badly just as it is about to lift off. It has
> > suffered a few collisions, as you might expect, and I am wondering
> > what I might have damaged.
> >
> > I have checked the balance of the rotor blades and that seems fine.
> > The document that comes with the model suggests checking things like
> > the main rotor shaft isn't bent but I haven't a clue quite how you
> > would check that. It looks to me that one rotor is possibly tracking
> > slightly higher than the other - could this be the cause?
> >
> > Any thoughts as to how I ought to proceed?
> >
> > Many thanks.
> >
> > Tim Kearsley



There are some very useful tips about the micro rc helicopters in here
- www.RCBOARD.net

[Brendan Hale]

It is also worth checking that the main blades are not too tight. I checked
over a Twister for someone last week and that had a lot of vibration. The
blades were done up far too tight and would not centre themselves. Once
loosened off a bit, the vibration disappeared.

HTH

Brendan