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#Post#: 22--------------------------------------------------
Different types of Radio Control Cars
DIR By: rch
Date: April 13, 2019, 4:16 pm
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Radio controlled or RC cars are battery/gas-powered model cars
or trucks that can be controlled from a distance using a
specialized transmitter or remote. The term "R/C" has been used
to mean both "remote controlled" and "radio controlled", where
"remote controlled" includes vehicles that are connected to
their controller by a wire, but common use of "R/C" today
usually refers to vehicles controlled by a radio-frequency link.
This article focuses on radio-controlled vehicles only.
Cars are powered by various sources. Electric models are powered
by small but powerful electric motors and rechargeable
nickel-cadmium, nickel metal hydride, or lithium polymer cells.
There are also brushed or brushless electric motors. Most
fuel-powered models use glow plug engines, small internal
combustion engines fueled by a special mixture of nitromethane,
methanol, and oil (in most cases a blend of castor oil and
synthetic oil). These are referred to as "nitro" cars. Recently,
exceptionally large models have been introduced that are powered
by small gasoline engines, similar to string trimmer motors,
which use a mix of oil and gasoline. Electric cars are generally
considered easier for the novice to work with compared to
fuel-driven models, but can be equally as complex at the higher
budget and skill levels.
In both of these categories, both on-road and off-road vehicles
are available. Off-road models, which are built with fully
functional off-road suspensions, and a wide tire selection, can
be used on various types of terrain. On-road cars, with a much
less robust suspension, are strictly limited to smooth, paved
surfaces. In the past decade, advances in "on-road" vehicles
have made their suspension as adjustable as many full scale race
cars, today.
Hobby-grade radio control models
In recent years, hobby-grade "ready-to-run" (or "RTR") models
have become readily available from major manufacturers of
radio-controlled cars, attracting many hobbyists who would
otherwise not have purchased a kit car. Vehicles of this type
need little or no final assembly and in most cases, the bodies
are shipped painted and trimmed. Safety inspection of the
product to ensure correct operation is essential, as injury to
operators or bystanders from disassembling vehicles is possible.
A number of cars and trucks are presently available only in
ready-to-run form. The growing popularity of the RTR vehicle has
prompted many manufacturers to discontinue production of kit
vehicles. High-spec racing vehicles are generally still
available or sold only as kits, and companies like Thunder
Tiger, Losi, HPI, Traxxas and Tamiya sell kit and RTR versions
with the benefits of a kit version being in upgraded parts or
lower costs, respectively. Hobby grade vehicles can cost much
more, ranging from $90 to over $2000.
Ready-to-run, As the name suggests, are pre-assembled models
ready for immediate use. They reach to speeds of about 70 miles
per hour (110 km/h), with some modified versions capable of
reaching 100 miles per hour (160 km/h).[1] There are versions
that run on both batteries and nitro.
Almost Ready To Run Cars, Commonly known as, the "Assemble it
yourself" cars. They are customizable, you can assemble the
parts on your own, they are ideal because you can acquire new
spares for broken parts and you can modify some features to
improve performance.They are mostly used by professional RC
drivers, you may also opt for the almost ready to run as a
beginner as it helps you develop your understanding for how the
different parts work and how to fix them.[2]
Electric models
Electrically powered models utilize mechanical or electronic
speed control units to adjust the amount of power delivered to
the electric motor. The power delivered is proportional to the
amount of throttle called for by the transmitter - the more you
pull the trigger, the faster it goes. The voltage is "pulsed"
using transistors to produce varying output with smooth
transitions and greater efficiency. Electronic speed controllers
use solid state components to regulate duty cycle, adjusting the
power delivered to the electrical motor. In addition, most
electronic speed controllers can use the electric motor as a
magnetic brake, offering better control of the model than is
possible with a mechanical speed control.
Mechanical speed controllers use a network of resistors and
switch between them by rotating a head with an electrode around
a plate that has electrical contacts. Mechanical speed
controllers are prone to being slow to react because they are
actuated by servos, waste energy in the form of heat from the
resistors, commonly become dirty and perform intermittently, and
lack a dedicated braking ability. They appear only in vintage RC
models, and are now essentially obsolete.
Most electric cars up to recently used brushed motors but now
many people are turning to brushless motors for their higher
power output and because they require much less maintenance.
They are rated either in relative turns or Kv. The Kv number
tells how many RPM the motor will turn per volt. However, the
ability of the system to put out power is dependent on the
quality of the batteries used, wires and connectors supplying
power. Due to their power, brushless motors are also used in
bigger monster trucks and 1/8 nitro-powered buggies that have
been converted to electric. High quality brushless systems can
be much more powerful than nitro and can accomplish feats such
as standing backflips when installed in a monster truck, most
notably the HPI Savage Flux. Some 1/5 scale gas to electric
conversions are in production but are uncommon due to high
price.
A new (2012) form of electric r/c racing is MAGracing. Small
1/32 scale cars and powered by rechargeable batteries and
steering and speed are controlled by r/c. Extra steering
guidance is provided by steel wires hidden in the track surface
enabling more accurate steering than is attainable with free
running r/c cars. Tracks can therefore be much narrower and
smaller making the system suitable for 'in home' racing. Cars
can be driven back onto the track after an 'off', using reverse
if necessary, so that track marshals are not required.
Nitro powered models
A Traxxas T-Maxx nitro powered off-road monster truck without
body. Nitromethane nitro powered models utilize a single servo
for throttle and braking control; rotation of the servo in one
direction will cause the throttle on the carburetor to open,
providing more air and fuel mixture to the internal combustion
engine. Rotation of the servo in the other direction causes
torque to be applied to a linkage and cam which causes friction
with the braking material. The brake is commonly located on the
driveshaft or spur gear in some cases and applies stopping power
only to the driven wheels. Some models will also use an
additional servo to control a transmission box, enabling the
vehicle to drive in reverse.
Fuel engine sizes most often range between 0.12–0.35 cubic
inches (2.0–5.7 cm3). This is due to restrictions by the main
sanctioning bodies for radio-controlled racing. Many "outlaw"
engines are manufactured larger than these, mainly intended for
vehicles which will not be used in sanctioned races and
therefore do not need to comply with these regulations. Engine
size is related to the class of car; 1/10 scale on and off-road
vehicles usually are equipped with .12–.18 cubic inch engines,
with 1/8 scale vehicles using .21–.32 cubic inch engines. There
are exceptions, with many Schumacher and Thunder Tiger/Team
Associated RC models being good examples of unusually large
engines coming as standard equipment on certain models.
Fuel-powered engines allow model cars to reach moderate speeds
unmodified. Maximum power is generally achieved at medium to
high speeds, and a slightly slower throttle response than
electrically powered vehicles is to be expected due to clutching
and lack of torque. Electric motors effectively produce
instantaneous torque, whereas nitro engines, like full-sized
gasoline engines, take time for the engine to spool up and for
the clutch to engage. Nitro- (and fuel) powered cars may be
refueled and returned to action in a few seconds, as opposed to
electrics which require removal of the body shell and battery
fasteners to replace a discharged battery. Nitro cars are cooled
some by air, some by the oil mixed in with the fuel and may be
run continuously with no need to take breaks for cooling down
assuming they are properly tuned.
Nitro-powered cars operate like full-sized fuel vehicles more
than their electric counterparts do, making use of a two stroke
engine rather than an electric motor. The sound of the engine
noise is a main selling points to nitro enthusiasts, even though
brushless electric equivalents are generally faster and do not
require special fuel. However, their exhaust contains unburned
oil, which usually ends up coating the chassis. This, in turn,
requires more cleaning than an electric-powered equivalent.
Cleaning is usually achieved by the use of compressed air
nozzles and solvents (such as denatured alcohol). Tuning a
fuel-powered vehicle requires learning to maintain optimum
performance and fuel economy, and to minimize engine wear and
overheating, even in ready-to-run vehicles. Running a nitro-fuel
motor without tuning or tuning improperly can hurt performance
in rich conditions, and cause severe damage in lean conditions.
Because of their ability to be driven for longer periods of time
and the use of burning fuel, mechanical wear in nitro vehicles
is generally greater than in electric vehicles. In addition, the
increased weight of fuel-powered vehicles generally lead to
higher speed collisions, causing greater damage to the collided
vehicles, and a greater degree of safety concerns needs to be
taken into account. Maintenance such as cleaning of the air
filter and general chassis cleaning, replacement of worn clutch
parts, proper after-run lubrication (necessary for storage) and
maintenance of other motor-related items such as glow plug
replacement makes for a more frustrating experience for first
time RC users. In addition, nitro motors typically require
rebuilding or replacement after 2–8 gallons (7–30 liters) of
fuel run through them, due to loss of compression, which can be
accelerated by poor tuning and overheating. It is also possible
to seriously damage the engines by over-revving them with no
load or ingestion of dirt into the carburetor. As such,
nitro-powered vehicles are by nature expensive to maintain.
Gasoline-powered models
Gasoline-powered vehicles, also known as "fuelies" or "gassers",
run on a mix of gasoline and oil. They cost much more (usually
$800–$3000 RTR) than nitro and electric cars. They are also much
bigger and therefore require much more space to run. They do not
usually have as high top end speeds (compared to nitro and some
electrics) but have lots of power and do not take a lot of fuel
to run. Over time the cost of a gas-powered car can be less than
some nitro-powered vehicles, because of the high cost of nitro
fuel and buying new nitro engines to replace worn-out ones. In
addition, gas-powered motors rarely if ever require tuning and
have a very long lifespan. These gas-powered vehicles really
pertain to the individual who is more interested in scale than
imagination. These large scale models have been popular in
Europe for over a decade and have recently become very popular
in the US thanks to companies like HPI Racing and FG Modelsport
producing affordable high quality models locally.
Accessories and Upgrades
All R/C models generally require the purchase of additional
accessories. For electrical vehicles, battery packs and a
suitable charger are needed to power the car and are seldom
included. A soldering iron and supplies are often necessary to
build high-performance battery packs or install upgraded
electronics with low-resistance connectors. A Li-Polymer battery
with a hard case is most popular for RC cars, with the most
common voltages being 7.4 V or 11.1 V. For nitro-powered
vehicles, a glow plug heater and fuel are needed to start the
engine, as well as 4 AA size batteries, or a rechargeable 6-volt
5-cell battery pack to power the on board electronics. Nitro
vehicles also require a means of cranking the engine over, which
can be achieved using a pull-start, starter box, battery
operated rotostart, or by an electric drill. The Traxxas nitro
rc cars come with a hand start up system, that revs the engine
and starts it up. It doesn't require a pull start system.
Relatively expensive model fuel, spare glow-plugs, and after-run
oil are also needed. Gasoline-powered vehicles require only a
receiver battery pack and a means to start the engine, usually
the included pull-start. Hobby-grade vehicles almost always
require 8 AA size batteries to power the transmitter, though
some can use rechargeable transmitter pack or simply
rechargeable AAs.
A large industry of aftermarket manufacturers produce upgrade or
hop-up parts for hobby-grade cars. Upgrades range from mere
improvements to the longevity of R/C car parts, to all-out
performance enhancements. A number of hobbyists create their own
upgrades for sale via classifieds and online forums. Hobbyists
choose to upgrade hobby-grade cars from plastic stock parts to
aluminium parts to increase strength and the steering angle of
the car.
"Ready-to-run" cars can be purchased, which leave the factory in
a pre-tuned condition that affords for good racing performance
without prior adjustment. However, as stated earlier, those
vehicles should still be inspected for loose parts prior to
operation as stated in many manuals. Alternatively, vehicles can
be purchased that are either in kit form or are partially
assembled, which are built and tuned by the owner prior to use,
but most of the time, the owner will have to buy radio gear, and
sometimes even an engine when they buy a kit.
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