LEGO fiber-optic elements are discontinued components that were available in a few Technic and Space sets from 1996 to 1998. They consisted of clear plastic tubes connected to a single battery-operated LED light hub to transmit light to different points of a model.
How They Worked
The system was designed to allow builders to add lighting to their creations without multiple light sources. A single electric hub (Part 6637) housed the battery and the LED light. Transparent plastic cables (e.g., Part 6640) were inserted into the hub, and the light traveled through the cables to illuminate the end points on the model, using the principle of total internal reflection. This approach was innovative but also costly to produce.
Discontinued Sets
Fiber-optic elements were a relatively rare and short-lived feature, appearing in only a few sets:
Space Shuttle (Set number: 8480, 1996): A flagship Technic set that was one of the first to feature the fiber-optic system for lighting the model's details.
Fiber Optic Multi Set (Set number: 8456, 1996): A versatile Technic set that offered instructions for building five different models (helicopter, racing boat, dragster, robot, bug), each designed to showcase the fiber-optic feature.
Interstellar Starfighter (Set number: 6979, 1997): A set from the LEGO Space theme that incorporated the fiber optics for added detail and effect.
Extreme Creatures (Set number: 9732, 1998): A set related to the LEGO Mindstorms line that included the fiber optic elements.
These elements are no longer in production, and working components can now only be found on the secondary market from re-sellers.