The pancake motor, as used in slot car

Slot car

A slot car is a powered miniature auto or other vehicle that is guided by a groove or slot in the track on which it runs. A pin or blade extends from the bottom of the car into the slot...

s, is a type of electric motor

Electric motor

An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...

, which has a flat commutator

Commutator

In mathematics, the commutator gives an indication of the extent to which a certain binary operation fails to be commutative. There are different definitions used in group theory and ring theory.-Group theory:...

 and vertical shaft. It was a feature of the highly successful Aurora  HO slot cars of the 1960s and 1970s. The motor was not a separate unit; instead, its individual elements - magnets, armature

Armature

Armature may refer to:* Armature , the kinematic chains used in computer animation to simulate the motions of virtual characters...

, commutator

Commutator

In mathematics, the commutator gives an indication of the extent to which a certain binary operation fails to be commutative. There are different definitions used in group theory and ring theory.-Group theory:...

 and brushes

Brush (electric)

A brush is a device which conducts current between stationary wires and moving parts, most commonly in a rotating shaft. Typical applications include electric motors, alternators and electric generators.-Etymology:...

 - fit into recesses in the blocky chassis. The power was carried by a chain of spur gear

Gear

A gear is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part in order to transmit torque. Two or more gears working in tandem are called a transmission and can produce a mechanical advantage through a gear ratio and thus may be considered a simple machine....

s along the top of the chassis, to a pinion which drove a crown gear at the axle.