Brushless Radio Controlled Cars
News, reviews, tuning and hop-ups
RC Glossary - The A to Z of Radio Control
S
Scale-- For Rc hobbyists, this refers to the general size of the car. Many companies
offer radio control cars in several different sizes: 1/18, 1/12, 1/10, 1/8, 1/5 and
1/4 scale. The smaller the number after the 1, the larger the actual scale car is.
For example, a 1/18 scale car is about 9 inches (23cm) long, while a 1/5 scale car
can be up to 36 inches (91cm) long! Most cars are of the 1/10 or 1/8 scale size (because
the cost of manufacture and ownership is balanced to the controllability of the car),
but there are many types of kits that fall under this size label: Buggy, Truck, Monster
Truck, Truggy, Touring Car and more.
Sedan -- In general terms, this refers to a 4-door
car that has a separate trunk. In Rc terms, this refers to a car that is generally
1/10 scale in size, and is one of the more popular form of on-road Rc racing in the
world right now. These kits started out modeling the cars that formed the DTM racing
league in Germany in the early 1990's, but (because of interchangeable bodies) now
can represent anything from the latest LeMans racer, to street trucks, to the newest
cruiser on the road.
Servo -- A small box full of motorized gears that turns the steering
and/or throttle linkage in an R/C car. Available in a range of strengths and speeds,
with the faster/more powerful servos more expensive than slower/weaker servos. Stock
servos usually cost about $15-30 (US dollars) and are the standard servos that are
included with most radio sets. These servos are fine to get a kit running, but in
the future you may want to upgrade to stronger servos, especially for racing or for
the steering of a large-tire off-road vehicle.
Shell -- Another term for a car body.
Side
Plates -- The sides of a wing, they help direct air over the wing and help in stability.
Larger side plates help in stability on a long straight section but can affect the
turning ability. Smaller side plates aid in turning but don't provide as much straight-line
stability.
Side Skirt -- The part of the body panel that is under the door. This term
usually refers to an extension of this panel that lowers the effective 'body ride
height'. Helps keep air from getting underneath the car, and helps channel air underneath
the car from the front to the rear, increasing downforce.
Shock Oil -- A petroleum-
or silicon-based oil that is available in different degrees of thickness, used to
fine-tune the damping of a shock absorber. As the shock shaft travels up and down,
the piston moves up and down also, so the oil must flow through the holes in the
piston. The smaller the holes are in the piston, the slower the piston is able to
move, and with larger holes the piston is able to move faster. When you are starting
out racing and you want to try adjusting your shock settings, you should try changing
your springs first, then your piston/shock oil combination.
Shock -- See Damping
Shock Absorber -- The complete assembly of a shock damper that
includes the shock body, cap, spring, shaft and connectors.
Shock Angle -- Move the upper end of the shocks up, and you should get more bite,
or grip, at that end. Lay the shocks further down, and you will loosen that end of
the car.
Shock Bladder -- Many shocks use a shock bladder to assist in bleeding the
shocks properly, and to make sure they maintain the correct pressure.
Shock Body --
The wide cylindrical part of a shock absorber that contains the shock oil, shock
piston and o-rings, topped by the shock cap and sometimes a shock bladder.
Shock Cap
-- Usually a threaded top (or bottom, on some shocks) that closes the shock body
and keeps the shock oil inside. Usually sealed with an o-ring, some shocks use a
shock bladder to help keep the oil pressure inside at a constant level.
Shock Shaft
-- The long metal rod that sticks out of the shock body, usually with a pivot piece
on the end that mounts to a suspension arm. The other end (inside the shock body)
has a shock piston on it.
Shock Spring-- The coil spring that usually surrounds the
shock body of an oil-filled shock. Some shocks consist of just the spring (like a
pan car front shock).
Shock Travel -- This does not refer to shock spacers that clip
to the shock body, compressing the spring. There are two ways to limit shock travel:
Spacers inside the shock, under the piston on the shock shaft or an o-ring or two
on the outside of the shock body, on the shock shaft above the spring retainer. The
inside spacers limit how far down the shock can extend, and the more you have, the
shorter the shock gets at its full length, but you may have to change your ride height.
The outside spacers (be sure to use old o-rings!) remove shock travel without compromising
the shock length or ride height, so the shock can still deal with dips in the track,
but stroke is lessened.
Silicone -- A type of synthetic rubber that is heat-resistant
and more durable than standard or natural rubber.
Sleeve -- Refers to an internal part of a nitro engine, which the engine's piston
slides up and down in. If the engine's sleeve is replaced, the piston must also be
replaced and the engine broken in. Sleeves in 2-stroke R/C car engines are either
nickel-plated or chrome-plated. Nickel plating offers cheaper parts but it can wear
out faster. Chrome plating is more expensive but worth it for racing.
Slipper -- A short term for the slipper clutch.
Slipper Clutch -- A traction control
device that uses metal plates and a fiber pad that controls how much power is transmitter
from the drive gears of an Rc car to the rest of the drive train. Used mainly on
off-road vehicles.
Speed Controller -- Another name for electronic speed controller.
Speedo
-- Another name for electronic speed controller.
Spoiler -- An angle on the rear of
a car that is built into the body lines of the car, or bolted on. No space exists
between the spoiler and the bodywork. A front spoiler is technically an air dam.
The angle that the spoiler contacts the air is the angle of attack.
Spring Rate --
This basically refers to the stiffness of a set of springs. If you want more traction
at one end, put on a softer set of springs. If you want less traction, harder springs.
If you are bottoming out or the track is really bumpy and the soft springs can't
extend fast enough to make the tires contact the surface, put on stiffer springs.
If you change the spring rate by a large margin, you'll probably have to switch out
the oil or pistons too.
Spur Gear -- The large (usually plastic) gear that a pinion
gear or clutchbell turns to provide power to a car or truck drivetrain. Available
in different pitches. Many newcomers to the Rc hobby will ask about metal spur gears
to prevent gear stripping, however it is usually gear mesh that determines if the
gear strips out or not.
Standard Narrow-- see width, wheel.
Starting Grid -- The order
the cars are lined up at the start of a race. Most races are started with Le Mans
Starts, meaning the cars start from a dead stop.
Straightaway-- Normally refers to
the longest, straightest part of a race track. If there is any place to go full throttle,
this is it!
Steel -- Not used very often throughout a modern Rc kit, steel is a strong
yet heavy metal that is still used in some critical parts of today's Rc kit. Typical
places you can find steel on an Rc car: pinion gears, turnbuckles or threaded rods,
axles, dogbones, ball ends, screws and lock nuts.
Steering Arm -- Parts of a bellcrank
steering system that are connected with a central Ackerman link and connect to the
steering knuckles with turnbuckles or fixed links.
Steering Block -- see steering
knuckle.
Steering Knuckle -- Generally, this refers to the of the car's front suspension
that steers the wheels. The steering turnbuckles connect the steering arms and steering
knuckles. The front axle will be connected to or pass through the knuckle. If the
car is four-wheel drive, the steering knuckle will have two bearings or bushings
that support the front axle. Sometimes the steering knuckle can be referred to as
front uprights, front hub carriers, or steering blocks.
Steering Link -- The turnbuckle
or fixed link that connects the steering arms in a bellcrank steering system to the
steering knuckle.
Steering Servo -- The servo that controls the direction of the front
wheels of a car.
Straight Axle -- Another name for pan cars, so called because of
the axle that goes all the way across the rear end of the car.
Stroke -- How far the
shock absorber can compress. Can be limited by clips or o-rings on the shock shaft.
Super
Narrow -- see width, wheel.
Super-Size -- A class of cars that feature larger bodies,
tires, chassis and suspension arms to have a larger car overall. Easier to drive
because of their larger size, the Super-Size class is really taking off!
Super Touring
-- Another name for sedan racing or touring car racing.
Suspension Arm - A part of
the car to which the uprights, hub carriers, shocks and/or steering knuckles are
attached. It will swing up and down as it is absorbing bumps or lowering into dips.
It is usually in the shape of a capital "A", which is where the name "A Arm" comes
from.
Sway Bar -- Bars that attach to the suspension arms at either or both the front
or rear end to limit wheel travel and take away some traction. Normally used only
for fine-tuning the car. Not recommended for bumpy tracks. Use a thin bar at first
to experiment, then try thicker bars.
