F
Fade -- see Brake Fade.
Failsafe-- A device that is built into a receiver or that plugs between the receiver
and servos that prevents a runaway car in the case of battery failure or loss of
signal.
Feint -- When coming up on a corner, to make a quick maneuver in the opposite
direction to get a better line through the corner.
Final Drive Ratio -- The transmission
ratio determined by combining the internal drive ratio and the spur/pinion combination
with this formula:
spur gear tooth count
divided by pinion gear tooth count
multiplied by the internal
drive
ratio
or
spur / pinion
* internal drive ratio =
final drive ratio.
If you are trying to match the gearing of another driver who uses a different pitch
pinion/spur combination (64 pitch instead of 48 pitch, etc.), or a driver that uses
another brand of car, you can use this formula to get a better idea of what to use.
Just get the internal drive ratio of the other car and find out the pinion/spur gears
that are used, then adjust your gearing to match the final drive ratio of the other
car. Remember to account for the motor being used, modified motors vary widely as
more or less turns are used, and even stock motors are different from their construction,
brush or spring usage, etc.
Fixed Link -- A type of linkage that cannot be adjusted,
usually used on ready-to-run cars for camber and steering links. Easily replaced
with turnbuckles for experienced racers who with to alter the car's setup.
Flex --A
measurement of how much a certain part will bend under varying degrees of pressure
or force. Every part will bend or flex, some more than others.
Flywheel -- The flywheel
helps the engine's crank shaft maintain momentum and aids in idling. A heavier flywheel
will aid in torque (pulling power and acceleration), while a lighter flywheel will
aid in top speed but may cause trouble with engine idling.
FM -- Short for Frequency Modulation, an FM radio in Rc is considered a better radio
than the cheaper AM radios because an FM radio will have less glitching than an AM
radio. Most hobbyists will be fine with an AM radio, but racers can benefit from
FM or PCM radios.
Foam Donuts -- Literally donut-shaped pieces of foam, these are
mounted on wheels so that pan cars and touring cars can use them. Some race tracks
are able to use foam tires (such as indoor carpet tracks for electric cars, or very
smooth and clean outdoor tracks for nitro cars), but most racers use rubber tires.
Foam tires have the advantage that inserts are not needed, they have better grip
than rubber tires, they can last longer than rubber tires, and racers can use rollout
calculations to figure out their gearing. However, ride height must be adjusted as
the foams wear out, and on a 4WD car the wear must be closely monitored to make sure
the car does not pull to one side as the car moves.
Foam Inserts -- In the early days
of Rc, tires were either foam (for on-road use) or hard rubber (for off-road). The
foam donuts did not need inserts, and the off-road tires were hard enough that they
could support the weight of the car without collapsing. As tire and car development
continued, the tires got softer and required inner foams to make the tire keep its
shape on the track. Touring car development followed the same trend as off-road tires:
early tires were made of a hard enough rubber that no inner foam was necessary, and
eventually tires got soft enough to require them. Most soft compound tires come with
a open cell foam insert, while modern sedan racing tires since about early 1999 come
with no foams at all, so racers can choose the best molded inner foam for their specific
needs. If you do not race, you can use (and re-use, when the tire is worn out) the
standard open cell foam insert that comes with your tires. If you do race, you would
be well advised to ask around at your local track to find out what tire and insert
combination works best!
Fuel Tubing -- Flexible silicone tubing that provides a way
for fuel to get from the fuel tank to the engine carburetor, and air pressure to
get from the muffler or tuned pipe to the fuel tank.
Full-Size -- After talking about Rc cars all day, you may want to discuss real cars
with your friends - use the term full-size to make the distinction!
G
Gear -- A general term that normally refers to either the spur gear and pinion gear.
Gearing
-- In general terms, this refers to the ratio of the spur gear and pinion gear, when
compared to the internal drive ratio of the car.
Getting Lapped -- A term used when
the lead car in a race is passing another car. That car loses a lapor goes a lap
down to the leader. If you are getting lapped, it's usually good form to let the
leader get past you in a turn by going wide through the corner. This is even more
important if the leader is battling with another car.
Glitching-- The term that refers
to your car losing control temporarily, another term for interference. This happens
when the signal from the radio transmitter to the receiver is interrupted for some
reason. To solve glitching, make sure you have fresh batteries in your radio, you
aren't running near overhead power lines, the antenna on the radio and the car is
fully extended, the car antenna isn't in direct contact with carbon fiber or graphite
parts (they cause interference), the car antenna isn't cut and the car antenna isn't
wrapped around itself. Sometimes twisting the motor wires will help solve glitching.
In severe cases, you may have a defective or broken receiver or transmitter. Consider
sending either or both to the manufacturers for repair (after talking with their
customer service people). In extreme cases you may want to consider replacing your
radio gear (get a new FM radio, etc.) or a new receiver.
Groove -- also known as the
racing line, this is the fast way around the track. The quickest way to get around
the track is not always a straight line from corner to corner. This term is usually
most used in oval racing.
Grooving -- no, not dancing! This is a term used to describe
the way some tires have a tendency to develop a groove on the inner edge of the tread
as they wear. This is less likely to happen to belted tires or tires with firm inserts.
Grooving is also a condition that occurs when you have too much negative camber in
your car.
H
Header-- A bent piece of aluminum tubing used on Nitro cars that transfers exhaust
gases from the engine case to the tuned pipe or muffler.
Hinge Pin --A straight pin
of steel or titanium that allows the suspension arms to pivot in one direction. Normally
3mm or 1/8 inch in diameter, a hinge pin can be any length.
Hit --Another term for
glitching
Hub Carrier-- Also called uprights, these are the parts of the suspension
that hold the axles and bearings the wheels of the car turn on.
I
Inner Foams-- Another term for <AHREF="#INSERTS"insert.
Inserts -- Foam strips or
donut-shaped cutouts that support a tire on a wheel. The car can be tuned with inserts,
much like full-size race cars are tuned with tire air pressures.
Interference -- see
glitching
Internal Drive Ratio -- A measure of the teeth of a car's gears and pulleys.
For Rc cars, you divide the number of teeth on the ball or gear diff pulley or gear
by the number of teeth on the smaller drive pulleys.
J
We currently have no definitions in this section of the glossary. Do you have any
suggestions?
If so, use the form at the bottom of this page to have them included.
K
Kick-Up-- While caster refers to the upward angle at the front wheels of the car,
kick-up refers to the upward angle of the front suspension arms. Technically, buggies
and off-road trucks have kick-up, not caster, but since they are so similar in description
most people use the term caster.
L
Lapped -- See getting lapped
Lean-- A condition referring to engines where the engine
is not getting enough fuel. While running lean can help performance and fuel economy,
you run the risk of running the engine too hot and blowing the engine! If your engine
runs for a few minutes and shuts off suddenly, it's probably running too lean.
Locknut--
A type of nut that features a nylon insert that helps to grab the threads of a shaft
or bolt, helping prevent the nut from loosening. Commonly used on axles and other
critical areas of Rc cars and trucks.
Loose-- See Oversteer
M
mAh -- An abbreviation for milliamp hour, a technical term that shows how long a
given power source (like a battery) can give off power.
Main, or Main Event-- In Rc
car and truck racing terms, this refers to the final race of the day in each class
you are entered in. See Qualifier, then read the rest of this definition.
Right after
all the qualifying races are over, the race computer will sort all the racers, with
the 10 fastest racers in the A Main, the next 10 fastest in the B Main, and so on.
The number of racers in each main may vary, depending on the number of total racers
in the class. Each main event is run in order from the highest letter to the lowest.
For example, if there are enough racers to make an E Main, the E Main is run first,
then the D, the C, the B, the A, etc. The winner of the A Main is the winner for
that class.
Large events (National and World Championships) will usually have what
are called Triple A Mains. This is only for the top ten racers in each class, and
they will all run three main events. In this case, your two best finishes count towards
the final score, so if you win two races in the Triple A Main, you would be crowned
the champion.
Mid-Narrow -- see width, wheel.
Milliamp -- A rating given to batteries,
generally the higher the milliamp rating, the longer the cell can provide power.
Currently, batteries are available for Rc use that range from 1500 to 3800 milliamps.
Mini
-- From the Morris Mini Cooper, Mini refers to an Rc car that is roughly 1/10 scale
but models a very small real-life car like the Mini Cooper, VW Polo or the Daimler/Chrysler
A-Class. The general difference between a Mini car and a regular sedan car is that
the wheels, tires, body, suspension arms and chassis are smaller. For cost-saving
measures the rest of the parts are generally interchangeable, especially the drivetrain,
bulkheads and shock towers.
Molded Inner Foam --A form of tire insert that is molded
in a special mold instead of cut out of foam sheets. While more expensive, the molded
inner foam stays in place on the wheel and does not move side to side as the car
goes through cornering forces.
Motor -- In Rc racing this generally refers to an electric
motor.
Muffler -- Installed on every Nitro-powered car, the muffler system traps exhaust
gases from the engine case and provide pressure to the fuel tank while keeping noise
levels to a minimum. Tuned pipes are another type of exhaust system that provide
more power than a muffler.
