This is an attempt to collect the common (and some what uncommon) jargon that is used in RC (and aeromodelling in particular).

It is preferred that each term be introduced in a separate post.  Also put in a small description, a picture or two if needed, and how it affects the performance of a model.  Should be useful to everyone, especially beginners.

It is good to know about dihedral, sweep and drift !  

some of them are

rolling takeoff or ROG (right off ground)

= Basically, it's just the taxiing to, and turning onto the end of the takeoff runway, and commencing the the takeoff roll, all in one continuous movement, without stopping

simply put

take off from the end of a runway or a runway and not hand launch

a video to support what i just said

http://www.youtube.com/watch?v=_N2n4VP6W20&feature=related

subbu

Subbu

I could also say that ROG means "Rise of the ground"...

Another jargon is

LIPO = Lithium Polymer battery pack... The most common rechargeable and dependable battery pack suitable for Electric planes which require utmost care in their handling and charging. Capable of overloading to a high degree... eg. a 2200maH (milli ampere hour... unit of charge) 3S1P LIPO today is capable of being overloaded to 25times its nominal capacity i.e. 25*2.2amps = 55amps for a short duration.

before the next one here is the pic for the one mentioned by saju uncle
lipo


ok guys here comes a big one

TX and RX

TX = transmitter (in nearly every case). well transmitters are used to control the motors rpm and the control surfaces and much more



RX = receiver. it is the most integral part of your planes system as it receives and processes the commands from the tx and converts it into the movement of servos or rpm of motor, etc



subbu

ESC : Electronic speed controller

BEC: Battery eliminator circuit

a bit of expansion to the above post

BEC = Battery eliminator circuit = it is a circuit which supplies power to the receiver directly and uses up one channel in the rx (mostly). these days the bec's are built into the esc's which directly power the system through the rx's throttle channel hence the same channel can be used for both supplying power to the rx and controlling the throttle



ESC = Electronic speed controller = An electronic speed control or ESC is an electronic circuit with the purpose to vary an electric motor's speed.An ESC can be a stand-alone unit which plugs into the receiver's throttle control channel or incorporated into the receiver itself.



subbu

ps.
anyone with better explanations please come up
please help by contributing more of these as they will help many

DIHEDRAL

Dihedral-what are they?- the upward bend of the wings from their center in sync with the horizontal plane from the center of the wing is called a dihedral.

probably you did not understand hence a picture to help you understand



what does this dihedral do??

it is a very good stabilization mechanism on the roll axis. that is it stabilises the plane to fly straight and level.

why do we need it

in most cases we use planes with dihedral to teach people to fly planes as it becomes very easy for them to handle and the plane itself becomes very forgiving.

any disadvantages??

yes it reduces the effect of ailerons on the plane as it continuously tries to keep the plane level.


some examples -   





POLYHEDRAL

polyhedal has the same effect but provides much more better stabilization. polyhedral are the upward bends at the wing tips.

for example -



subbu

hey anwar bhaiya can we have a jargon cum dictionary in this same thread please reply

subbu

More of the RC jargon...........Whats Dual rates and Exponential. Never understood it right yet! Maybe cos its bcos of the very basic radio that i use...................
Edwin

Subbu - You might want to clarify your post about BECs with information on "built-in BEC"s versus "external BEC"s.  Also, what exactly are we "eliminating" ?

Onto dual rate and exponentials.

DUAL RATES

Dual rates can be easily understood  as the reduction of throw/deflection/movement of a control surface for a given amount of stick input.  Let us say the ailerons on a plane has 30degrees of upward and 30 degrees of downward deflection by default, giving a total 60 degrees of deflection between the two extreme positions of the control stick input.  If we enable "50% dual rates" on it, we restrict the movement of the control surface to 15degrees on each side, thus helping to "tame" the model down (which is particularly helpful for beginners), at the same amount of maximum stick input.

EXPONENTIAL

In this case, if we go by the same example above and we had say negative expo, the total deflection between the full control inputs stays at 60 degrees, but the amount of control surface deflection is lower towards the center of the control stick movement range and higher towards the extremes of control stick movement.  So at half stick movement in either direction, instead of the control surface deflecting 15degrees, it would deflect say around 7.5degrees.  But at full application of the control stick to any side, the control surface would deflect the full 30 degrees.  So for a given amount of control stick movement, the control surface movement is "tame" towards the centre of the stick movement range, and remain "wild" towards the extremes of stick movement.

Anwar

Maybe this chart would make it clearer

Thanx Anwar and Saju.

QuoteMaybe this chart would make it clearer

This is just to represent what expo is. Varying the amount of expo would change the curve leaving the end points ( 1.0 & 2.0 ms.) the same. Do note that it is also possible to "reverse" the expo curve where you would get increased response around neutral.

QuoteSubbu - You might want to clarify your post about BECs with information on "built-in BEC"s versus "external BEC"s.  Also, what exactly are we "eliminating" ?

What one is "eliminating" is the need for another battery for the receiver. The power is derived from the motor battery and regulated o a lower level.

External "BECs" are effectively the same but not part of the ESC.  They are regulators that use a LiPo battery, again regulated to the lower level (5V or 6V) needed by the receiver. Most ESCs have the BEC included. But external ones would be needed to power the electronics of non electric models with a LiPo battery.

Quote from: sushil_anand on October 15, 2009, 11:23:25 AM
Most ESCs have the BEC included. But external ones would be needed to power the electronics of non electric models with a LiPo battery.

Even electric fliers go for external BECs occasionally as a an added safety measure.  This is particularly applicable to electric helis that are in the 325mm blade size or higher (more common the 425mm blade size or higher).  Since lipos can drop their last bits of charge pretty quickly if one is not careful, a separate lipo+BEC setup allows the receiver and servos to work to land the model safely (even if the main lipo has lost its charge, enough to drive the electronics only otherwise).

Next set of terms.... what are these ?

Sweep
Revo Mix
High Alpha

SWEEP : Angular deviation from the spanwise axis. Could be forward or backward.

HIGH ALPHA : It is the angle of attack or the deviation from horizontal or flying axis. HIGH ALPHA would be a very nose high attitude.

These are basic and not detailed explanations.

SWEEP

http://en.wikipedia.org/wiki/Swept_wing

REVO MIX

When gyros were not common (especially heading hold ones), the radios were used to alter the pitch of the tail rotors in helicopters to counter the torque effects of changes in throttle.  In other words, Revo Mix adjusts the tail rotor pitch as throttle increases or decreases.  Many radios provide a "curve" for Revo Mix, allowing it to finely controlled over the various throttle inputs. Since the advent of heading hold gyros, this is practically never used.

This has many on 1 page:

http://www.futaba-rc.com/glossary.html

Quote from: anwar on October 14, 2009, 09:43:41 PM
Subbu - You might want to clarify your post about BECs with information on "built-in BEC"s versus "external BEC"s.  Also, what exactly are we "eliminating" ?

Getting Back to BEC's  it works this way  as I understand it :

Normally ESC's upto 30-40 amps have built in BEC's   and above 40 amps External BEC's are used  .

Many manufacturers will use the term OPTO in the Specifications  of  an ESC this normally means the ESC does not have a BEC . In this case it implies the ESC cannot power the receiver  and you need to use either an external BEC or Battery to power the receiver thru the battery channel.
The wiring diagram can be seen here for using an external BEC :
http://scriptasylum.com/rc_speed/_wiring.html

In case OF BEC's it is important to understand the voltage they can handle eg the RCFORALL 30 amps can handle 14.8 V power with the built in ESC but the 40 amp cannot  go beyond 11.1V . The internal BEC can be disconnected by cutting the positive wire ( red )

Sai

Camber: Camber is typically used on sailplanes and refers to the function of lowering the entire trailing edge of the wing to change airfoil of the wing, and therefore, the flight characteristics of your aircraft. Camber is typically used during launch to maximize lift.

Camber Point: The Camber Point function allows you to define how Auxiliary Lever (VR6) controls Camber. Based on the Camber Point setting, you can control both Camber and Reflex, or you can control only Camber or Reflex. When programmed to control only Camber or Reflex, the amount of servo travel will be doubled. This is useful for those pilots who want more overall travel, but in only one direction.

CCPM: Collective, Cyclic, Pitch Mixing. CCPM is software-controlled mixing that allows control of the collective, cyclic and pitch using three (and sometimes four) servos. This allows lower mechanical complexity and greater control precision. In this configuration the cyclic and collective controls are mixed. 3-Point and 4-Point mixes are featured.

CCPM Servo End Point Adjustment: The CCPM End Point Adjustment function allows you to adjust servo travel in each direction for the elevator, aileron, and pitch servos independently. Unlike standard End Point Adjustment, which affects all the cyclic servos, CCPM End Point Adjustment allows you to adjust each cyclic servo independently without any affect on the other cyclic servos.

CCPM Servo Linear: The CCPM Servo Linear function converts the rotary output of the servo(s) to a Linear approximation and helps correct any abnormal cyclic movement caused by off-center control arms when at full positive or negative End Points and allows you to adjust the overall Rates for the elevator, aileron, and pitch servos independently.

CCPM Servo Delay: The CCPM Servo Delay function allows you to adjust the speed of the elevator, aileron, and pitch servos independently. Even though the servos may be of the same type, not all servos operate at the same exact speed. If one or more servos controlling the swashplate is operating faster than another servo, this can cause swashplate geometry issues and even result in binding of the swashplate linkage assemblies. Slowing down the faster servo(s) to match the slower servo(s) helps to fine-tune the swashplate, ensuring the most accurate and smoothest movement as possible throughout the entire deflection range.

Crow: The Crow function allows you to use the ailerons and the flaps simultaneously to control the lift of the aircraft, while still allowing aileron roll control. Crow is typically used to quickly reduce lift, ensuring pin-point spot landings in nearly any situation. When the Crow function is Activated on the radio, all of the ailerons should move Up and all of the flaps should move Down.

Flaperons: Flaperons is a mix of flaps and ailerons, allowing you to use the ailerons as flaps if your model does not feature separate flaps. When Activated, both ailerons are moved down at the same time to provide the function of flaps, while still providing aileron roll control.

Governor: A Governor is an electronic device used on glow-powered helicopters, that, coupled with a high-speed servo, is used to control a helicopter's rotor head speed.