Brushless Radio Controlled Cars
News, reviews, tuning and hop-ups
RC Glossary - The A to Z of Radio Control
C
Calling Traffic -- Some tracks have a policy of telling racers that are getting
lapped that the leader of the race is coming up behind them. The backmarker is expected
to move over and not interfere with the leader and any battles for position. However,
not all tracks have this policy.
Camber-- Seen from the front and rear of the car,
the angle of the tires in relation to the ground; tires that are perfectly perpendicular
to the ground (90 degrees) are said to be at 'zero camber'. If the tops of the tires
lean towards each other, the tires have negative camber, and if they lean out, the
tires have positive camber. As a general rule, never have positive camber, and make
sure the camber of, say, your front right wheel equals the camber of your front left
wheel (make the camber angles on each axle match). If we were talking about oval
racing, the rules would be different, but we're not. Sedan racing, with it's straights,
turns and chicanes requires that, among other things, camber angles match. Usually
one degree of negative camber on the fronts is good, because you want a good contact
patch throughout a turn, and one or two degrees of negative camber on the rear wheels
is fine. From there, experiment, one degree at a time.
Camber Link--Normally made
up of a turnbuckle or threaded rod with a ball cup at each end, this allows the suspension
arm and upright to flex a little more than an upper arm would.
Carburetor– (Nitro
only) Called carb for short. The mechanism on an engine that controls the ratio of
fuel and air that enters the engine. There are different types of carburetors:
Barrel
Carburetor: the standard model engine carburetor, carried over from airplane engines
when they were adapted for car use. For most hobbyists and racers this type of carburetor
is fine, because it is simple to install and adjust. The throttle servo turns a barrel
which has a hole through it, and this controls the amount of air going into the engine.
A needle valve on the carburetor controls the amount of fuel going into the engine.
A
Slide Carburetor: a highly modified, car-specific type of carb that has the barrel
of the carb slide along its axis, instead of turning. This provides a quicker response
at the expense of a complicated set-up procedure. This type of carb has almost become
the industry standard for the RC Hobby. Two or three needle valves control the fuel
intake at different RPM ranges.
Car Stand -- Simply, this is something a R/C car will be on while work is being done
to it. It can be as simple as a block of wood, or as complicated as a padded rotating
stand with parts bins. Another main function of a car stand is to keep the wheels
off the ground during breakin and while work is being done.
Caster -- Almost every
car has some caster built-in. Caster is the angle that the car's front wheels pivot
on when turning. Most on-road Touring Car type kits use between 5 and 10 degrees
of caster. Off-road kits like buggies and trucks have about 25 to 30 degrees of 'kick-up'
on the front axles. More caster generally gives more steering going into a turn,
but less coming out. The opposite is also true: less caster give less steering going
into a turn (initial steering), but more steering as you exit. Caster also gives
more stability on straightaways, but this effect is more pronounced in 2WD vehicles.
Cell
-- Another term for batteries, but in a singular reference (such as, look at this
cell), this generally refers to the nickel-cadmium or nickel-metal hydride batteries
used in Rc cars.
Center of Gravity -- can be shortened to CG or cg. A point in space
that represents the central point of a car's mass. If you don't race or are just
starting, the only thing you need to know about center of gravity is that if you
have a high CG the car or truck will be easier to tip over in tight turns, especially
at high speed. As you get more experienced in racing, you will learn to keep everything
on the car or truck as low as possible to enhance handling.
Chassis --The foundation
of an Rc car or truck, this is the main portion of the car that everything attaches
to. It can be made from woven graphite, moulded plastic composites or aluminum. Normally
it is flat with lightening holes cut into it but if moulded from plastics it can
have bent-up sides and other features.
Class --In radio controlled car racing, the class refers to the type of car you have,
and what class it would race in. In general, there are Touring Car, Mini, 2WD buggies,
2WD trucks, 4WD buggies, Rally, Super-Size, Oval Pan Car, 1/10th scale Pan Car, 1/12th
scale Pan Car and a couple of other classes. These classes are further divided by
the mode of power, either Electric or Nitro. The some of the popular classes are
electric and Nitro Touring Car, electric 2WD buggy, nitro 4WD buggy, Monster Truck,
Truggy and Stadium Trucks. To just name a few. When deciding what type of kit you
want to get for your first R/C kit, try to decide what type of kit and what type
of power source you will get, this will narrow your selections down considerably!
Closed
Cell Foam -- A type of foam that is moulded, normally used in Rc for molded inner
foams. More expensive than open cell foam, it holds its shape better and if moulded
it does not move back and forth on a wheel.
Clutch Bell-- The equivalent of a pinion
gear on a nitro engine, the clutch bell is on the end of the crank shaft and connects
with the car's spur gear(s). In a cutaway view, the clutch bell looks like a bell,
which is where it gets the name. Inside the hollow part of the clutch bell are the
clutch shoes, which will expand with engine RPMs to come in contact with the clutch
bell, making it spin. This makes the spur gear turn, and the car moves forward!
Clutch
Shoes -- Clutch shoes are attached to the engine flywheel and expand under increasing
RPM to contact the clutch bell. The clutch bell spinning makes the spur gear turn,
and the car moves forward!
Compound-- When talking about tires, the firmer (harder)
the compound, the longer life it will have, but it won't have as much grip as a softer
tire would. Most racers use a firm compound tire as the racing surface heats up during
the day. A softer compound tire is best used when the track is cool, such as in the
morning or late evening. Examples of these compounds include 20R tires (softest),
23R, 27R (medium), 33R and 35R (firmest).
Contact Patch-- The footprint of the car's
tire, or the area of the tire that comes in contact with the ground at any given
moment. Affected by camber, turning and acceleration. A wider contact patch (from
wider wheels) does NOT mean you will automatically get more traction.
Coupe -- In
general terms, this refers to a 2-door car. Some Rc touring car body manufacturers
offer bodies that represent full-size cars.
Crank Shaft-- A part of a Nitro engine
that is rotated by the piston, providing circular motion to the outer part of the
crank shaft, which is attached to the flywheel and clutch shoes.
Crystal-- The part
of a radio system that tells the transmitter to emit a particular frequency, and
also tells the receiver to look for a particular frequency. Crystals normally are
packaged in pairs, because the receiver requires a different crystal than the transmitter.
You must use the same frequency crystals in the transmitter and receiver to make
the car respond correctly to your commands.
CVD-- An abbreviation for Constant Velocity
Drive. CVD is a trademark of MIP (Moore's Ideal Products, Inc.). MIP offers their
CVD universal dogbones for many Rc Trucks and Cars. The main features of the MIP
CVD's are their improved efficiency over standard universal dogbones, ability to
be rebuilt if an axle or bone is bent or damaged and ease of finding replacement
parts.
