Twister vibration

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

Tim Kearsley - 23 Nov 2004 13:35 GMT

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

Reply to this Message

Dave Yates - 23 Nov 2004 15:29 GMT

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

> Hello all,
>
[quoted text clipped - 19 lines]
>
> Tim Kearsley

Reply to this Message

NBA - LA - 23 Nov 2004 20:47 GMT

> 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
[quoted text clipped - 34 lines]
> >
> > Tim Kearsley

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

Reply to this Message

Carl Farrington - 23 Nov 2004 20:22 GMT

> 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

Reply to this Message

Brendan Hale - 26 Nov 2004 22:17 GMT

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

Reply to this Message

Model Forum / Radio Controlled / Helicopters / November 2004

Twister vibration