Brushless Radio Controlled Cars
News, reviews, tuning and hop-ups
RC Glossary - The A to Z of Radio Control
A Arm -- This generally refers to the lower suspension arm of the car, although it
can refer to the upper arm also.
ABS-- A form of plastic that is easy to form but
is not crash-resistant, however some of our 24mm wheels are made from ABS, which
is slightly lighter than the high-impact nylon used in our other wheels.
Accelerate
To make the car move faster, either from a full stop or while it's already moving.
Acceleration
A measure of how quickly a car can accelerate. Affected by items like the weight
of the car and its rotating mass.
Ackerman-- Rudolf Ackerman is a man who worked out
a steering system for horse-drawn carts, and we use his name today to describe the
angle of the inside tire in relation to the outside tire when the wheels are turned
to full lock--the farthest the wheels go to the left or right. Normally, when the
front wheels are turned all the way left or right, the inside wheel is at a sharper
angle than the outside wheel. If you extend the center line of each front tire to
a point where the intersect and measure that angle, that is the Ackerman angle. Ideally,
for perfect steering, the Ackerman angle will cross at the center line of the rear
axle. In a wide turn, the front tires are not turned very far to the right or left,
the inside wheel is not steering at a sharper angle than the outside wheel, and the
Ackerman angle is not very wide. In a tight turn, the inside wheel is steering at
a steeper angle than the outside wheel, and this is what is called the Ackerman effect.
A bellcrank steering system approximates a way to copy the Ackerman effect, and is
adequate for R/C cars because of tire slip, tire sidewall folding and other factors.
Adjusting the Ackerman angle can be done by changing the length of the center link,
also called the Ackerman link that connects the bellcrank steering arms, or changing
the mounting location on the steering arms without changing the link length. Most
racers won't need to change the Ackerman angle, and actually it is best left to experienced
racers who wish to try something new. Mounting the Ackerman link to the outer holes
will result in a small Ackerman angle. Using the inner holes will increase the Ackerman
angle. A smaller Ackerman angle (done by lengthening the Ackerman link or using the
outer link holes) will give you more aggressive steering into a corner with a possibility
of oversteer at the middle of turn, when the most weight is on the outside tires.
A larger Ackerman angle (achieved by shortening the Ackerman link or using the inner
link holes) will give you more predictable and smoother steering. Ackerman Link--
The center link of the bellcrank steering system that connects the two steering arms.
Air Dam -- An extension of the front bumper that blocks, or dams, too much air from
getting under the car and producing lift. Most R/C bodies for Touring Cars have air
dams built in.
Aluminum -- In general terms, aluminum is a metal that is lighter than
steel,but not as strong. It can be machined (cut on a machine) to replace many plastic
parts of an R/C car, but is not recommended for replacing suspension arms.
Angle of
Attack-- (AOA) Refers to the angle that a surface contacts the air, usually mentioned
when talking about spoilers and wings. A higher AOA helps solve oversteer but increases
drag and decreases top speed. A lower AOA is used to alleviate understeer and increase
top speed.
AM -- Short for Amplitude Modulation, an AM radio in R/C is considered
a budget radio, what most newcomers to R/C will start out with. Most hobbyists will
be fine with an AM radio, but some racers can benefit from FM or PCM radios. An AM
radio will have more glitching than these other, more expensive radios.
Anti-squat--
Refers to the angle of caster on the rear wheels. However, that angle prevents the
squatting of the rear suspension, so 'anti-squat' it is. Anti-squat is most effective
on acceleration from a stop, when much of the car's weight is forced onto the rear
suspension. Lifting the front of the hingepin of the rear arms gives a caster (anti-squat)
angle, and helps to transfer the power that makes the car want to do a wheelie into
forward motion.
Axle -- What a wheel of a car spins or rotates on. A drive axle is
an axle that is actually powered and turns the wheel (such as the rear axles on a
rear wheel drive car), otherwise the wheel will spin on bushings or bearings on the
axle.
