Radio-controlled car

Kyosho Inferno 1/8-scale buggy

A radio controlled car is a powered model car driven from a distance by a hand-held radio transmitter which sends its control information to the car's onboard receiver. Building, driving and modifying radio-controlled car kits is a hobby enjoyed by enthusiasts of all ages.

Types of cars

File:Rc sedan.jpg

1/10-scale electric sedan

Radio-controlled (or R/C) cars can be categorized two ways, electric-powered and gas-powered. Electric cars use small but powerful electric motors and rechargeable nickel-cadmium or nickel metal hydride cells to power them, while so-called "gas" cars use small internal combustion engines powered not by gasoline but by a special nitromethane/methanol/castor oil fuel mix. Recent years have seen the introduction of exceptionally large models that are in fact powered by small gasoline "weed-eater" engines. Electric cars are generally considered easier for the novice to work with than gas but can be equally as complex, possibly more so, as one's skill and budget pave the way for more sophisticated electronics.

In both of these categories, the hobbyist can choose between either on-road or off-road vehicles. Off-road models with their fully functional suspensions can be used on various types of terrain, while on-road cars with their limited or even non-existent suspension travel are strictly limited to smooth, paved surfaces.

Maintenance

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Modified 1/8-scale buggy with upper body removed

Regardless of the category chosen, hobby-grade radio controlled cars require regular maintenance for smooth and trouble-free operation, unlike the cheaper and unserviceable toy-grade cars found in discount and consumer electronics stores. To the mechanically inclined, this is just another fun aspect of the hobby. However, another consideration is the availability of many replacement and high-performance parts for hobby-grade models which allow one to upgrade and modify their car even to the extent of having no original kit parts remaining whatsoever. Conversely, if a toy car breaks, parts are nearly impossible to find. Also, toy cars are notoriously difficult to disassemble. Having a hobby-grade car means that in the event that parts break or wear out, they can be replaced individually. In light of this fact, Radio Shack released the popular XMODS and ZipZaps toy cars. These mid-grade cars can each be tuned, modified, and repaired, though still to a lesser degree than hobby-grade.

In recent years, excellent hobby grade ready-to-run models have become available from every major manufacturer, attracting many who otherwise may have purchased an assembled toy car. Vehicles of this type need little or no final assembly and in some cases, even the bodies are painted and trimmed. A number of cars and trucks are presently available only as ready-to-runs. Recent examples include the Traxxas Revo and Hobby Products International Savage 25, both nitro-powered monster trucks.

History

Small, nitromethane-powered engines debuted in the 1940s. Unfortunately, the technology of the time simply didn't allow for the control of an engine-powered model car other than on a tether. Tether cars or "spin dizzies," while capable of speeds upwards of 70 mph (113 km/h), did nothing but run in a circle. It wasn't until the late 1960s that the first wave of miniaturized solid state radio control systems became available. These systems allowed a model to have remote, servo-controlled steering and throttle/brake, proportional to the motion and throw of the transmitter controls. Now instead of running in a circle, an engine- or electric-powered model car could be made to run around a racetrack with the subtle control of its full-sized counterpart.

In 1976, recognizing the potential for this new hobby was a Japanese firm, Tamiya. Renowned for their intricately detailed plastic model kits, Tamiya released a series of beautiful but mechanically crude 1/10- and 1/12-scale car models that were, according to the box covers, "suitable for radio control." Though rather expensive to purchase, the kits and radio systems sold as fast as hobby stores could stock them. Tamiya eventually turned their attention away from scale detail and toward the development of more purpose-built R/C models. Featuring working suspensions, more powerful motors, knobby off-road rubber tires and often topped with stylized dune buggy bodies more closely resembling something from an anime cartoon than anything on the street or sand dunes, these rugged models were easy to assemble, easy to repair, affordable to buy and modify and would serve as the basis around which the radio controlled car hobby would blossom both for backyard fun and for competition. See also: [[Tamiya Blackfoot]].

Fun as the Tamiya kits were, it would be US and European companies that would turn the world's attention to a more advanced form of R/C racing competition.

Britain's 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).

Buying a RC Car

Just like buying a real car, deciding which type of RC car to buy can be a difficult decision. First off, you need to ask yourself if you want to get serious into this hobby or just play around. Of course, if you want to play around, then a low budget model would suit you. But if you want to get into serious racing, then you'll want a high end car.

After making that decision, the next step is to decide if you want a electric powered car or a nitro powered car. Each car has it's own advantages and disadvantages. Electrics are usually cleaner to run, they're lighter in weight, and maintenence. After running a few races with electric cars, the only dirt is basically the dust on the track (if there is any dust at all). The light weight of electric cars allow them to speed up very quickly despite the motor choice. Another advantage it will have against nitro engines are that electric motors have a linear torque band throughout the RPM, and have better throttle response. Electric batteries, however, take a long time to charge. Maintenence is usually done by cleaning and inspecting the car for damages and replacing any parts that may have gotten damaged during play. Motor maintenence is fairly simple for non-race tuned motors. The disadvantages of electric cars are they are generally slower than nitro, unless expensive upgrades are added to match the speed of nitro cars.

Electric racers will need to perform extra maintainence to keep the performance level up. High performance electric motors should be allowed to cool down between runs to avoid demagnetizing the permmanent magnets. A spray down with motor cleaning solution is needed between runs to avoid wear from dirt and dust. Then the bearings (or bushings) in the motor must be re-oiled. Advanced racers have access to lathes, which true the motor commutator. This is necessary, because the commutator degrades quickly from the high levels of current that racing demands. Replacing the motor brushes is another maintenence need for for advanced racing. The tires must be very carefully selected to match the racing surface for maximum traction. Racing tires wear out relatively quickly, compared to the less grippy--but more durable--play tires.

Both nitro and electric models require additional accessories. For electrics, battery packs will be needed to power the car. A recharger will, of course, charge the batteries. More advanced hobbiests will buy lathes to maintain the commutator. A soldering iron and supplies are often necessary to build high performance battery packs and install upgraded electronics. Eight AA sized batteries are standard for the transmitter.

Now if you're in the market for a nitro car, usually ready to run (RTR for short) cars are great performers out of the box. Instead of charging batteries, the fuel tank is simply refilled. Nitro engines make plenty of power to rocket cars to impressive speeds, much higher top speeds than electric cars. Nitro engines make their maximum power at mid to high RPM's, and have a slightly slower throttle response than electrics. But as many advantages of nitro cars, there are disadvantages. A common one would be cleaning. Nitro cars get dirty very quickly. Even a 5 min run can dirty up a car. Cleaning usually requires compressed air blowers and solvents, such as denatured alcohal, because the exhaust and fuel coat the frame. Tuning requires some skill to keep the motor from overheating, even in out of the box configurations. Because of the higher performance and non-stop driving tendancies of nitro cars, driveline wear is higher than in electrics. And nitro cars are faster and heavier vehicles than their electric counterparts, leading to the inevitably more spectacular and damaging crashes.

Similar to electric cars, racers will have higher maintenence needs. The engine would have to be rebuilt regularly. A typical nitro engine costs around $150+. The average pro racer re-builds an engine once every 5 races and rebuilds usually cost almost as much as the engine.

For the nitro car, a glow plug warmer is required to start ignition, and twelve AA batteries are usually needed to run the electronics on the car, as well as the transmitter. The engine can be cranked with a pull cord, or started with an optional onboard electric motor powered by a seperate battery pack. Recently, cordless drills have also been adapted to replace the pull starts and electric starts. More advanced racers may start their nitro cars with a starter or "bump" box, which turns the flywheel directly.

There are also 2 other aspects to pick from: on-road and off-road. On-road cars are restricted to smooth paved roads. Off-roads can basically go anywhere. From parking lots to construction yards, offroad vehicles have almost no limits at all. Another up-side to offroad vehicles is that they are much more durable than on-roads. With their thick beefy suspension arms and thick alloy chassis they are pretty much indestructible. One very famous truck that started the RC truck revolution is the Traxxas T-maxx. Other manufactures started to follow with their own versions of the monster truck such as the HPI Savage and the Tamiya TNX. There are electric trucks out there too, but not as popular as nitro powered ones. But in either case, the advantages and disadvantages of each powerplant is similar to those discussed previously.

Widespread R/C racing comes of age

In 1984, Associated Electrics, Inc. of Costa Mesa, California introduced an important off-road electric racer. Dubbed RC10, this car was not only a bold departure from Associated's regular line of nitro-powered on-road race cars but a study in engineering as well. Designed as a serious miniature racing machine, the RC10 sported a chassis of anodized, aircraft-grade 4140 aluminium alloy. Every fastener was of the same material and identical to those used in aircraft. Also in 4140 alloy were the machined, oil-filled and completely tuneable shock absorbers. Other machined metal parts abounded. Suspension control arms were high-impact nylon as were the two-piece wheels. Even optional stainless steel miniature ball bearings found their way into many an RC10's wheels and transmission. That same transmission sported an 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, and it wouldn't be long before other companies took pursuit of the RC10's unprecedented success.

In 1986, Schumacher Racing Products Ltd. of Northampton, England released their first CAT `Competition All Terrain', considered the best four-wheel-drive off-road buggy 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, especially in the field of injection molded plastics. When the first Team Losi buggy, the JRX-2 hit the track in 1988, it sparked a rivalry with Team Associated that continues to this day. Team Losi would go on to pioneer a number of firsts, including 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 states, Traxxas (another American company) and Kyosho (from Japan) were also making competitive two-wheel-drive off-road racing models. Although Losi and Associated rivalry was tough in the USA, Schumacher off-road models seemed to be more suited to European tracks.

The mid-90s saw a rise to a new bread of RC cars, 1/10th touring. Schumacher Racing pioneered this class once again. Associated was soon to follow. This class saw the rise of Tamiya and other Japanese manufacturers rise back to a very competitive level. To date, nearly all manufacturers have produced a 1/10th touring car, either electric or nitro.

Racing

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1/12-scale onroad electric with body removed

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 is 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.

Drifting

Drifting refers to the difference in slip angle between the front and rear tires of a car. When the rear wheels are slipping at a greater angle than the front wheels, the car is drifting, or oversteering. The rear end of the car appears to chase the front end around a turn, the driver utilizes both front tires and the rear tires to control the actual direction of the car. Like larger vehicles, RC cars both electric and gas powered cars can accomplish this skill with pracite and some supplies such as black PVC pipes as tires to allow for drifting and grip on the road. Any type of pvc Piping can be used as tires but black pvc has a better grip. Black PVC can be obtained a local hardware or plumbing store. To set up a RC car drift the link is on the External link.

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.

External links and Related Articles

ROAR, IFMAR, BRCA and RC Pro Series are some US and International racing organizations.
radiocontrol on radiocontrol, an external wiki
RC Tech, RC Nitro, Radio Controlled Car Action and HobbyTalkhave many information-packed articles on this topic. These sites represent monthly periodicals as well.

The following sites have information on specific brands of cars. Many excellent brands are available with these being among the most popular: