4.5V Motor with Wheels (Large Version)

The 4.5V Motor with Wheels, cataloged as set 100-2, was introduced by the LEGO Group in the late 1960s as a core component of the brand's pioneering electric train and vehicle systems. Emerging from an era when LEGO sought to transition from simple building blocks to sophisticated mechanical toys, this motor provided the kinetic foundation for the System i Leg system. It was engineered to offer children a reliable way to introduce movement into their custom builds, representing a significant technological leap for the company’s push into powered accessories.

The design focused on robustness and compatibility, featuring a blocky, utilitarian aesthetic that allowed it to be seamlessly integrated into standard LEGO chassis. Designed by the in-house development team during the company's early expansion into motorized play, the unit was praised for its simplicity and the tactile satisfaction of the gear-driven mechanism. It remains a hallmark of 1960s industrial toy design, remembered by collectors as the piece that bridged the gap between stationary models and active, moving play.