Gears were invented so that large forces could be transmitted between two rotating shafts. There are a few simple geometric relationships which govern the operation of gears. First, moving gears in mesh act like wheels that are rolling against each other without slipping. Gear teeth are much more effective in preventing slipping than friction between smooth wheels.
The pitch of a gear is the distance between equivalent points on adjacent teeth. For two gears to mesh they must have the same pitch. The pitch circle of a gear is an imaginary circle which passes through the point where the teeth touch when one gear meshes with another. The pitch diameter is the diameter of the pitch circle.
Pinion gears are attached to a motors shaft, either by solder or a press fit.
Spur and Crown gears are attached to the axle of a car. Spur gears are used for sidewinder type installations and are most common. Crown gears are used for inline applications and are typical in retro and drag racing.
We stock a large selection of gears from every major manufacturer for nearly all slot car racing applications.