Radio-controlled car
From Free net encyclopedia
A radio-controlled car is a powered model car driven from a distance using a radio control system. Inputs from joysticks on a transmitter are sent the car's onboard receiver. Building, driving, and modifying radio-controlled car kits is a hobby enjoyed by enthusiasts of all ages.
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Types of cars
Radio controlled (or R/C) cars can be categorized in two ways, electric powered and gas powered. Electric cars use small but powerful electric motors and rechargeable nickel-cadmium, nickel metal hydride, or lithium polymer cells to power them. Some radio controlled cars use small internal combustion engines fuelled by a special mixture of nitromethane, methanol, and oil (either castor oil or synthetic oil), which are referred to as "gas" cars. Recently, exceptionally large models have been introduced that are powered by small gasoline engines. Electric cars are generally considered easier for the novice to work with than 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, can be used on various types of terrain. In comparison, on-road cars, which generally have a limited or non-existent suspension, are strictly limited to smooth, paved surfaces.
Maintenance
All hobby-grade radio controlled cars require regular maintenance to ensure smooth and trouble-free operation. In comparison, cheaper "toy-grade" cars, found in discount and consumer electronics stores, are generally unserviceable. For those interested in mechanics, this maintenance provides an interesting adjunct to the hobby. Due to their modular construction, in the event that parts of a hobby-grade remote control car break or wear out, they can be replaced individually. The availability of many replacement and high-performance parts for hobby-grade model vehicles allows them to be extensively upgraded (sometimes, to the extent of having no original parts remaining whatsoever of the vehicle); in comparison, parts are generally impossible to find for toy-grade model cars, which are notoriously difficult to disassemble. In recognition of this distinction, Radio Shack released the popular XMODS and ZipZaps toy cars; these are mid-grade cars which can be tuned, modified, and repaired, although still to a lesser degree than professional hobby-grade vehicles.
In recent years, hobby-grade "ready to run" models have become available from every major manufacturer of remote control cars, attracting many hobbyists who would otherwise have purchased a pre-assembled toy car. Vehicles of this type need little or no final assembly and in some cases, the bodies are shipped painted and trimmed, requiring no further work from the owner before they can be used. A number of cars and trucks are presently available only in ready-to-run form; recent examples include the Traxxas Revo and Hobby Products International (HPI) Savage 25, both fuel-powered model vehicles.
History
The beginnings of model racing
Small, nitromethane-powered engines originally entered the market in the 1940s. At the time, there was insufficient technology to control an engine-powered model car other than on a tether. "Tether cars", or "spin dizzies", were capable of speeds upwards of 70 mph (113 km/h), but merely ran in a circle from the tether. In the late 1960s, the first miniaturized solid state radio control systems became available, which allowed a model car to have servo-controlled steering, throttle, and brake functionality that could be remotely controlled from a radio control transmitter unit. This allowed model cars to be able to run a racetrack, with the ability for precise control in a similar manner as with a full-sized vehicle.
First commercial products
In 1976, the Japanese firm Tamiya, who were renowned for their intricately detailed plastic model kits, released a series of elegant but somewhat mechanically crude car models that were sold as "suitable for radio control". Although rather expensive to purchase, the kits and radio systems sold rapidly; Tamiya eventually turned their attention away from scale detail of vehicles and towards the development of more purpose-built remote control model cars. Featuring working suspensions, more powerful motors, textured off-road rubber tires and often topped with stylized "dune buggy" bodies, these models were durable, easy to assemble, capable of being modified, and simple to repair. These models can be credited with launching a boom in the popularity of radio controlled model cars in the early to mid 1980s, and they provided the basis for today's radio controlled car market. Popular Tamiya models included The Grasshopper and The Hornet dune buggies as well as the Blackfoot and Clodbuster monster truck models.
A British firm, Schumacher Racing, was the first to develop a ball differential in 1980, which allowed nearly infinite tuning for various track conditions. At the time the majority of on-road cars had a solid axle, while off-road cars generally had a gear-type differential. Team Associated followed suit with the introduction of the RC-10 off-road racing buggy in 1984 (see below).
Modern developments in radio controlled racing
In 1984, Associated Electrics, Inc. of Costa Mesa, California introduced the RC10 off-road electric racer; this model was a departure from Associated Electrics' regular line of nitromethane-powered on-road race cars. Designed as a more professional radio controlled car, the chassis of the RC10 was manufactured from anodised, aircraft-grade aluminium alloy. The shock absorbers were machined, oil-filled and completely tuneable; they were also produced from the same aluminium alloy. Suspension control arms were manufactured from high-impact nylon, as were the two-piece wheels.
Optional stainless steel miniature ball bearings were sometimes incorporated in RC10 wheels and transmissions. The RC10 transmission contained innovative differential featuring - hardened steel rings pressed against ball bearings - which made it infinitely adjustable for any track condition. The RC10 quickly became the dominant model in electric off-road racing.
In 1986, Schumacher Racing Products released their CAT (Competition All Terrain) vehicle, widely considered the best four wheel drive off-road "buggy" racer of the time. The CAT went on to win the 1987 off-road world championship, following suit in 1990, 1994, 1995, and 1996. This car is credited for sparking an interest in four wheel drive electric off-road racing.
Gil Losi, whose family ran the "Ranch Pit Stop R/C" racetrack in Pomona, California, turned his college studies toward engineering, primarily in the field of injection molded plastics, leading to his foundation of Team Losi. When the JRX-2, the first Team Losi buggy, was released it initiated a rivalry with Team Associated that continues to this day. Team Losi went on to secure a number of achievements, which included the industry's first all-natural rubber tires, the first American made four wheel drive racing buggy, and an entirely new class of cars, the 1/18-scale Mini-T off-road electrics.
Although Losi and Associated seemed to dominate much of the American market, Traxxas (another American company) and Kyosho (from Japan) were also making competitive two-wheel-drive off-road racing models. Although Losi and Associated were close rivals in the USA, Schumacher off-road models continued to be popular amongst European hobbyists.
Technical aspects of radio controlled car racing
Electrically-powered models
Image:Rc onroad.jpg Image:Rc sedan.jpg Electrically powered models usually stay cleaner during operation, are lighter in weight, and require less maintenance than fuel-powered models. After having run a few races with an electric car, the only dirt accumulated on the vehicle is usually from track dust. The light weight of electrically-powered cars allows them to accelerate rapidly. Another advantage that electric cars has against fuel-powered engines is that electric motors have a more even torque; in addition, they also have better throttle response. Electric batteries, however, take some time to charge. Routine maintenance usually consists of cleaning, inspecting the model car for damages, and replacing any parts that have been damaged during use. The disadvantages of electric cars are they generally do not reach the same speeds produced by comparable fuel-powered vehicles, unless expensive upgrades are added. High performance electric motors must be allowed to cool down after use, to avoid demagnetizing the permanent magnets.
In terms of long-term maintenance of the engine, the application of motor cleaning solution is needed between runs to avoid wear from dirt and dust. Also, the bearings (or bushings) in the motor must be re-oiled periodically. Replacing the motor brushes is also sometimes required, and tires used must be very carefully selected to match the racing surface for maximum traction. Racing tires wear out relatively quickly, compared to "play tires", which are more durable but do not have quite as much traction.
Fuel-powered models
"Ready-to-run" fuel powered cars (commonly abbreviated to "RTR") can be purchased, which leave the factory in a pre-tuned condition that affords for good racing performance without prior adjustment. Alternatively, composite 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.
Fuel-powered engines allow model cars to reach impressive speeds, with much higher top speeds than electric cars. Maximum power is generally achieved at medium to high speeds, and a slightly slower throttle response than electrically-powered vehicles is usually expected. This is because in an electric motor, the torque is instantaneous; in a nitro engine, as in a gasoline engine, it takes time for the engine to spool up and for the clutch to ingage. Although this is slower than an electric motor, it is hardly noticeable because it all happens within milliseconds.
One disadvantage of fuel-powered engines is the dirt produced; a short five-minute run of such an engine is sufficient to coat the vehicle in dirt from fuel combustion. Cleaning is usually achieved by the use of compressed air blowers and solvents (such as denatured alcohol), because of the stubborn nature of the exhaust residue and fuel that tends to cover the chassis. Tuning a fuel-powered vehicle requires some skill to maintain optimum performance, fuel economy, and to keep the engine from overheating, even in ready-to-run vehicles. Because of the higher performance and their ability to be driven for longer periods of time, mechanical wear to the vehicle is generally greater than in electrics. In addition, the increased speed and weight of fuel-powered vehicles generally leads to collisions causing greater damage to the collided vehicles, and some degree of safety concern needs to be considered when racing them.
Accessories
Both fuel-powered and electric models generally require the purchase of additional accessories. For electrical vehicles, battery packs and a suitable charger are needed to power the car. A soldering iron and supplies are often necessary to build high performance battery packs and install upgraded electronics. For fuel-powered vehicles, a glow plug heater and fuel are needed to start the engine, as well as 4 AA size batteries to power the onboard electronics. Hobby grade electric and fuel-powered vehicles almost always require 8 AA size batteries to power the transmitter.
Racing
There are tracks and racing clubs around the world for enthusiasts to get together and race, and there are many levels of difficulty from novice all the way to professional, ensuring that there is a racing class regardless of skill or equipment level. R/C racing on a professional level is a serious motorsport, regardless of the size of the cars involved, with factory-backed drivers racing for cash purses all over the world.
Some commonly raced classes and the types of models that race them are:
- 1/12 Electric Onroad - Rear wheel Drive Cam Am-bodied cars, Touring cars, oval racers
- 1/10 Electric Onroad - Touring cars, Can Am-bodied cars, Formula One/Indy cars, oval racers
- 1/10 Electric Offroad - 2WD trucks, 2WD buggies, 4WD trucks, 4WD buggies, dirt track oval racers
- 1/10 Nitro Onroad - Touring cars, Can Am-bodied cars, oval racers
- 1/10 Nitro Offroad - 2WD trucks, 2WD buggies, 4WD trucks, 4WD buggies, dirt track oval racers
- 1/8 Nitro Onroad - Touring cars, Can Am-bodied cars
- 1/8 Nitro Offroad - 4WD buggies, 4WD trucks
It should be noted that the fractional number used throughout this article refers to the model's scale in proportion to its full-sized counterpart. Therefore, a 1/10-scale car is one-tenth the size of a real car, though most purpose-built racing models are not built to true scale.
Not all tracks will race all classes, as terrain, space and noise requirements differ from class to class. It also means that the same track cannot always be used for more than one or two similar classes.
However, if the class you drive in is not raced at your local track, yet is similar to a class that is raced, it is often possible to run with the other cars. This obviously must be discussed with the race coordinators prior to the race, and usually depends on the willingness of the coordinators to bend the rules in order to encourage new members to the track...and therefore to the hobby. In a race sanctioned by a governing body such as ROAR (Radio Operated Auto Racing) and IFMAR (International Federation of Model Auto Racing), the rules clearly define that only vehicles of the same class may be run together.
In the United States, the main sanctioning body for racing is ROAR, itself a part of the worldwide IFMAR racing organization. At the ROAR level, there are thirteen different regions in the US and one region for all of Canada. Each region has a championship race, including the US Nationals. Placing well in the nationals will qualify a person for the Worlds Races, sanctioned by IFMAR. The IFMAR Worlds are the pinnacle of radio controlled competition. After winning the 1/10th Electric Off-Road Worlds in 2003, Team Associated driver Billy Easton retired from racing and continued his college education. He has since returned to professional racing.
The world's most successful driver is Japan's Masami Hirosaka. Hirosaka has won fourteen world titles in all electric racing categories except 1/10th touring.
Toy radio control
The term toy or toy-grade in regards to radio control is used to describe radio controlled vehicles, vessels and aircraft of the pre-assembled type generally found in discount stores and consumer electronics stores. Some toy-grade R/C models may also be found in hobby shops in an attempt to appeal to young users.
Generally speaking, a toy R/C is meant as a child's or adolescent's plaything. Though sometimes derided by users of more expensive and sophisticated hobby-grade equipment, toy R/C is an excellent way to teach a youngster basic vehicle control and to hopefully spark his/her interest in the hobby at a very reasonable price. Modern toy R/C vehicles are fast, fun and even rather flashy in comparison to hobby-grade vehicles. A toy R/C Lincoln Navigator being brought to market for the 2005 holiday season features scale detail, full interior, chrome "dub" spinner rims, working show car lights and even a fully programmable, built-in mp3 player used to emulate a high-powered stereo system. One of the largest R/C car models of any type is the 1/4-scale Cadillac Escalade from Columbia Telecommunications Group with its working FM radio. A Humvee less the broadcast receiver is built on the same chassis. Both are powered by a large, heavy 12-volt gel cell of the type often found in electric riding toys. A model of a Chrysler 300 SR/T from Planet Toys is a full 1/5 scale, twice the size of many hobby-grade R/C vehicles. Jada Toys has introduced 1/6-scale R/C cars influenced by full-scale vehicles featured in DUB City magazine. The "Shell Shocker" is a spherical, paddle-driven, all-terrain vehicle whose configuration can be changed by radio control. It was inspired by the Teenage Mutant Ninja Turtles franchise and is sold by Tyco R/C.
There are disadvantages to toy R/C's as well. First is a lack of available repair parts. Toy R/C's are meant to be played with until they finally fail. Parts for such vehicles are not carried in the stores that sell them, unlike a hobby shop. Some basic parts may be available from the manufacturer - both Tyco R/C and New Bright have a basic parts list enclosed with their models - but they can be prohibitively expensive and parts may take several weeks to arrive from their Asian factories. Radio equipment, unlike hobby-grade, is non-standardized and non-repairable unless one has the necessary tools and equipment. Except for RadioShack's line of ZipZaps toy R/C cars and their XMODS line which falls between toy- and hobby grade, no aftermarket parts are available for toy R/C, although an enterprising modeler may be able to retrofit standard, discrete radio gear to a toy. Control response on some toy models comparable in size to hobby-grade vehicles is often slower than hobby-grade which actually makes those toys difficult to operate with smoothness and precision. An example is the aforementioned 1/4-scale Escalade and Humvee; they are promoted as having "semi-proportional" steering.
World speed record
The 2003 Guinness Book of World Records lists the fastest-ever top speed of a radio-controlled car as 111 mph (178.63 km/h) set by Cliff Lett of Associated Electrics. Lett, a Team Associated professional driver and one of the designers and developers of the aforementioned RC10, set the record with a heavily modified Associated RC10L3 touring car at Irwindale Speedway on January 13 2001. More can be found about the record at: Need For Speed
References
See also
External links
- ROAR, IFMAR, BRCA and RC Pro Series are some US and International racing organizations.
- RC Nitro, Radio Controlled Car Action, rcsite, RC411, and RC Car Talk have many information-packed articles on this topic. These sites represent monthly periodicals as well.
- HPI Racing
- Kyosho
- Mugen Seiki (English)
- Ofna
- Schumacher Racing
- Tamiya
- Team Associated
- Team Losi
- Traxxas
- Yokomo
- Duratrax
Other
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