Hello,

I'm completely new to this hobby (still in the reading/learning phase). there's something i'm not clear about.

from what i understand, cyclic controls work by moving the swashplate which in turn causes the blades' pitch to change (at a specific location during their travel ...)

now I know there are CP (Collective Pitch) helicopters and FP (Fixed Pitch) helicopters... how can a FP helicopter have cyclic controls if the pitch of the blades cannot be changed ?!?!

please enlighten me

thanks!

I am going to go out on a limb here and say this. FP helis use the swashplate to angle the ROTOR ASSEMBLY. CP helis, in addition, have the ability to change the pitch of the rotors themselves. They TWIST oppisite of each other. I am new to helis as well and I am sure someone will correct me if I am wrong.

The pitch of the blades are NOT changed in FP helis, the swashplate is purely for tilting the rotating disk of the blades to create movement in a particular direction. All helicopters use this method from a co-axial (which only affects the lower blades) to ccpm helis. The swashplate is controlled by the right stick for aileron and elevator movement.

In ccpm helis, the throttle stick controls both power and changes the pitch of the blades. Both the power and pitch have throttle curves associated with them which can be changed in a computer radio. The pitch of the blades are controlled by the swashplate moving up and down the main shaft which in turn has a controlling rod which connects to arms on the blade holders. In FP helis the swash plate is fixed and will not move vertically, only tilt.

YesI ment tilt the whole rotor assembly in FP Helis for the cyclic.
Collective changes the picth of the rotors. The swashplate tilts fowards. backwards an left and right for the cyclic and moves up and downvertically for the collective. I think I have a clearer picture now.

Druss,

"All helicopters use this method from a co-axial (which only affects the lower blades) to ccpm helis."

are you saying that cyclic controls work by tilting the rotating disk (with respect to the helicopter) rather than adjusting the pitch of the blades at a specific location (though the swashplate) ? this goes against what is explained here:

"http://www.rchelicopterfun.com/helicopter-controls-cyclic.html"

I would understand if that was the case for FPhelis ... but for CP helis i would expect cyclic controls to work the same way as explained in the link.

that makes sense to me ...

so in CPhelis, the swashplate can be tilted and also moved up and down (so directional control and lift control is acomplished by simply tilting blades)

on FP helis, lift is accomplished by speeding up / slowing down the main motor and directional control is accomplished by tilting the whole assembly, ie the rotating plane is tilted w.r.t. to the heli

is that it ?

you got it! won't put any more into this as different people explain in different ways and it all gets a bit unnecessary

best thing to do if you have any more doubts/ confusion is go down your LHS (local hobby store) and get them to show you one of each and their control movements but i think you've sorted it out in your own mind!!

Matty )<>}}}}}}]@>