Slot cars are usually models of actual automobiles, though some have bodies purpose-designed for miniature racing. The voltage is varied by a resistor in the hand controller.
Most enthusiasts use commercially available slot cars (often modified for better performance), others motorize static models, and some "scratch-build", creating their own mechanisms and bodies from basic parts and materials. This is a basic circuit, and optional features such as braking elements or electronic control devices are not shown.
Drivers generally use a hand-held controller to regulate a low-voltage electric motor hidden within the car. Likewise, the car's frame or chassis has been omitted for clarity.
Traditionally, each car runs on a separate lane with its own guide-slot (though recently developed digital technology can allow cars to share and change lanes). HO slot cars work on a similar principle, but the current is carried by thin metal rails that project barely above the track surface and are set farther out from the slot.
The challenge in racing slot cars comes in taking curves and other obstacles as fast as possible without causing the car to lose its grip and spin sideways, or to 'deslot', leaving the track altogether. The car's electrical contacts, called "pickup shoes", are generally fixed directly to the chassis, and a round guide pin is often used instead of a swiveling flag.
Some enthusiasts, much as in model railroading, build elaborate tracks, sculpted to have the appearance of a real-life racecourse, including miniature buildings, trees and people. Today, in all scales, traction magnets are sometimes used to provide downforce to help hold the car to the track at higher speeds, though some enthusiasts believe magnet-free racing provides greater challenge and enjoyment and allows the back of the car to slide or "drift" outward for visual realism.
Hobbyists whose main goal is competition often prefer a track unobstructed by scenery. There are three common slotcar scales (sizes): scale, scale, and so-called HO size ( to scale).
Model motorcycles, trucks and other vehicles that use the guide-slot system are also generally included under the loose classification of "slot car." Typical electrical circuit of a or slot car track. These are also commonly written as 1/24, 1/32, 1/87 and 1/64.
Power for the car's motor is carried by metal strips next to the slot, and is picked up by contacts alongside the guide flag (a swiveling blade) under the front of the slot car.
The diagram at right shows the wiring of a typical or slot car setup.
Usual pronunciation is "one twenty-fourth", "one thirty-second", and so on, but sometimes "one to twenty-four", "one to thirty-two".
In addition to the major scales, slot cars have been commercially produced in scale and scale, corresponding to O gauge model trains.