Brushless Radio Controlled Cars
News, reviews, tuning and hop-ups
RC Glossary - The A to Z of Radio Control
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 manoeuvre 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!
