View Single Post
Old Sep 09, 2005, 08:11 PM
n/a Posts
Re: finished biulding Raptor 50 but

"R A" <mgroverelectronics(remove)> wrote in message
> Thanks Beav I got there in the end.


As you say should take a breath when
> writing. :-).


Got another problem though which I'm trying to sort in between
> other things. The heli runs sweet and fly's well or as well as I can fly
> it, but when I land & the rotor slow I get a bad vibration and the whole
> heli shakes like F???. But when taking of there is a slight shake as it
> gets up to speed. I am in the process of balancing the blades but they
> don't seem to far out, they are the original wood ones that came in the
> kit.

If the heli runs smoothly when things are spinning at flying speed, then
it's not a balance problem, so it'll be either a resonance problem or
something REALLY simple like the blades not being tight enough in the grips.

If they're not tight enough, they lag behind the rotor shaft as the motor
drives it, and as the blades eventually "catch up", things smooth out. The
"ideal" friction on the blade grips is enough to hold the blades in position
when you hold the heli at 90 degrees to the ground (like a tightly banked
turn), but held by your hand. A "shake" of the heli should see the blades
slip in the grips. Any looser and you'll have the "wind-up vibes".

The resonance problem (if it IS that) can be addressed by shortening the
blades by half an inch, or adding/removing tip weight. Aslo, flying from a
hard surface doesn't help either, so if you're doing that, try flying of

Get thee to checking.


Reply to "beavis dot original at ntlworld dot com" (with the obvious