Confusion with some basic terms

[Stone Mason]

Do all of these terms mean the same thing?
Cyclic Pitch Forward
Elevator Up
:confused:Pitch Up:confused:
Nose Down

[Dubya_o]

Cyclic pitch forward = nose down = down elevator

Cyclic pitch back = nose up = up elevator

[xptical]

Cyclic is the right stick (on Mode 2). It's Aileron and Elevator on an airplane. A lot (99%) of guys still call it A/E.

Collective is the combination of throttle and pitch. As you move the left stick up and down, you get two outputs at the RX end. On a full sized heli, the throttle is a twisty-grip (like a motor cycle) on the collective stick. You twist the grip to get more gas and pull the stick to get more pitch.

[Augman37]

Thanks, those terms were confusing me too. It makes it worse when the old airplane terms are used to describe helis.

[vera]

Do all of these terms mean the same thing?
Cyclic Pitch Forward
Elevator Up
:confused:Pitch Up:confused:
Nose Down


There is room for some confusion regarding the word, "pitch". Mostly this word is used to refer to an angle on the rotor blades. But this word also refers to an axis of rotation of the heli. And to add to the possible confusion, the axiis have two names. Let's clear up the axis terminology.

"lateral axis" - also called "pitch axis"
Imagine a rod running laterally (left/right) through the machine. This rod is nailed down, cannot move. Therefore, the only thing the machine can do is rotate in such a way that the nose goes up/down. Thus the name, pitch axis. The term, pitch up/down refers to motion on this axis. The fore/aft cyclic stick controls movement on this axis. It tilts the swash fore/aft.

"longitudinal axis" - also called "roll axis"
Imagine a rod running longitudinally (front to back) through the machine. It's nailed down, cannot move. Therefore, the only rotation the machine can do is left/right. Thus the name, roll axis. Rolling left/right is motion on this axis. The left/right cyclic stick controls movement on this axis. It tilts the swash left/right.

"vertical axis" - also called "yaw axis"
Imagine a rod running vertically (top to bottom) through the hei, nailed down. Therefore the only rotation the machine can do is nose left/right. Thus the name, yaw axis. Left/right "rudder" (anti torque) stick controls movement on this axis. It changes the blade pitch on the tail rotor.

The other, more common meaning for "pitch" refers to the size of the bite the rotor blades take out of the air. Imagine a line perpendicular to the rotor drive shaft. When the flybar is "level" it represents such a line. Now imagine a line running through the blade from front to back. The angle between these two lines is the "pitch" angle that instruction books talk about in the setup section. This pitch is controlled by the same stick that also controls the throttle. Most transmitters have a pair of "curves" that allow you to control how much pitch and throttle are applied at various stick positions. Frequently these curves have five adjustment points. Point #1 applies at the low stick position, on up to point #5 which applies to high stick position. At each of these points you can set the throttle anywhere between cutoff and full throttle on one curve, and on the other curve you can set the blade pitch anywhere within it's range of adjustment.

If someone yells at you, "Pitch up", it could mean, pull the nose up, or it could mean, pull the collective up. There is room for confusion here. Probably, "pull up" is what would be said if they meant to pull the nose up, and "pitch up" would probably be said if the collective was being referred to. Anyway, hope this clears up a dab of confusion.