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-   -   I need a crash course on what rudders/elev/ailerons do. (https://www.rcuniverse.com/forum/aerodynamics-76/9553897-i-need-crash-course-what-rudders-elev-ailerons-do.html)

krazekajin 03-04-2010 10:18 AM

I need a crash course on what rudders/elev/ailerons do.
 
As my title says, Ineed a crash course (pun intended) on what the control surfaces do on a plane. For example I fly a three channel parkzone vapor. This is my first plane. It has a rudder and elevator. Obviously, when I use my rudder it turns. That's easy. When I push up on my elevator, the plane fly's down and when I push down on my elevetor, the plane flies up.

Now, what does the ailerons do.Or better yet, what is different on a four channel plane.I believe that the ailerons are located on the main wings. Do they move independentaly of each other, which requires two servos, or do they move the same much like both sides of the elevtor?

gboulton 03-04-2010 10:28 AM

RE: I need a crash course on what rudders/elev/ailerons do.
 
http://en.wikipedia.org/wiki/Aircraf...control_system

Enjoy :)

krazekajin 03-04-2010 10:34 AM

RE: I need a crash course on what rudders/elev/ailerons do.
 
That was what I was understanding. The Ailerons are for rolls (simple answer). Now my other question is the ailerons are designed to work opposite of each other.One goes down and the other goes up. Does that require two servos or does one servo cause the opposite reactions?

gboulton 03-04-2010 11:33 AM

RE: I need a crash course on what rudders/elev/ailerons do.
 

ORIGINAL: krazekajin
That was what I was understanding. The Ailerons are for rolls (simple answer).
Simple, and also completely correct. :) That's what ailerons do...roll. :)


Now my other question is the ailerons are designed to work opposite of each other.One goes down and the other goes up. Does that require two servos or does one servo cause the opposite reactions?
Can be done either way, it depends on the airplane, its design, your choices, etc etc.

Some airplanes have one (or more than one, for some big ones!) servo per aileron. Like so :

http://www.rcuniverse.com/magazine/r...%20linkage.jpg


Others have one servo in the middle of the wing, actuating "torque rods" or some other sort of linkage which allows a single servo to move both ailerons in opposing directions. Like so:

http://www.rcgroups.com/articles/ezo...51/aileron.jpg




Bax 03-04-2010 11:35 AM

RE: I need a crash course on what rudders/elev/ailerons do.
 
To understand flight controls and how to control an airplane, you need but one resource:

Stick and Rudder, by Wolfgang Lagenwiescheavailable through almost any bookseller. It's been in print since the late 40's, early 50's or so, and is very relevant for model flyers, since all airplanes fly the same way.

For your ailerons, you can use one servo with appropriate linkage, or two servos, directly operating a single aileron each. Very large models have multiple servos on the control surfaces to make sure there's enough power. Basic models, though, usually need only one servo to operate ailerons.

[edit for typos]

krazekajin 03-04-2010 12:45 PM

RE: I need a crash course on what rudders/elev/ailerons do.
 
Thank you very much. That is what I'm looking for.


gboulton 03-04-2010 12:49 PM

RE: I need a crash course on what rudders/elev/ailerons do.
 


ORIGINAL: Bax
To understand flight controls and how to control an airplane, you need but one resource:

Stick and Rudder, by Wolfgang Lagenwiescheavailable through almost any bookseller. It's been in print since the late 40's, early 50's or so, and is very relevant for model flyers, since all airplanes fly the same way.
Seconded<br type="_moz" />

Top_Gunn 03-04-2010 12:57 PM

RE: I need a crash course on what rudders/elev/ailerons do.
 

Obviously, when I use my rudder it turns.
Not that obvious. Why does it turn? Because the motion of the rudder causes the plane to yaw, which in turn makes it bank (because the wings have dihedral), and then the lift makes the -plane turn. You'd get a really weird turn using just rudder if you didn't have dihedral.

"Stick and Rudder" is indeed a terrific book.

Tall Paul 03-04-2010 01:25 PM

RE: I need a crash course on what rudders/elev/ailerons do.
 
1 Attachment(s)


ORIGINAL: Top_Gunn


Obviously, when I use my rudder it turns.
Not that obvious. Why does it turn? Because the motion of the rudder causes the plane to yaw, which in turn makes it bank (because the wings have dihedral), and then the lift makes the -plane turn. You'd get a really weird turn using just rudder if you didn't have dihedral.

''Stick and Rudder'' is indeed a terrific book.
Roger bof'em!
This one flies real funny! :)

Guillermo Ibanez 03-04-2010 02:21 PM

RE: I need a crash course on what rudders/elev/ailerons do.
 


ORIGINAL: krazekajin

When I push up on my elevator, the plane fly's down and when I push down on my elevetor, the plane flies up.
If you pull back on elevator stick on your transmitter, the plane fly's up and viceversa

That means that if elevator surface is up, the tail of the plane is lowered and the plane fly's up and vice......

BRG






<br type="_moz" />

krazekajin 03-04-2010 02:22 PM

RE: I need a crash course on what rudders/elev/ailerons do.
 


Thank you for the clarification.
</p>

I was oversimplifing, I realize that almost every aspect of flight is a conbination of many different controls.Yet, I still have lots to learn and the more I fly, the more Ilearn and the more questions Iwill have.
. I will have to look into that book.</p>

BMatthews 03-05-2010 01:02 AM

RE: I need a crash course on what rudders/elev/ailerons do.
 
In case you missed it I'll just stress the earlier post about how the rudder and dihedral work together to roll the model into the turn. The rudder only yaws the model. The dihedral when yawed causes the airflow to strike the two wings with different angles of attack and that generates more lift on one wing and less lift on the other to roll the model. Ailerons do the exact same thing by altering the camber and angle of attack for each wing to roll the model.


As for linkages to connect the ailerons to one servo the strip ailerons driven from near the center line is one way. Also way back when servos were too pricey to use one in each panel but when we wanted to use normal outer panel only ailerons like in a scale model we used to use one in the center laid down with the output out to either side with pushrods running through the wing to bellcranks to "turn the corner" and then short pushrods from the bellcranks to the ailerons. Later on with the arrival of Nyrods some folks gave up on the bellcranks and used the Nyrods where they run out along the wings and then curve through a 90 degree bend to drive the conventional outer only ailerons directly without requiring bellcranks.


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