Page 192 - LEGO MINDSTORMS - Robotics Invention System-2 Projects

Robot 6 • The Aerial Tram

The LEGO Aerial Tram is modeled after the Aerial Tram that glides over the
Arkansas River, slicing through the granite canyon of the Royal Gorge in
Colorado. Trams are built to traverse expanses that are often at great heights or
in areas where bridges are difficult to build. Aerial trams can have many pur-
poses—some trams are for sightseeing, some are for cargo or passenger trans-
portation such as ski lifts, and some are built to complete tasks such as
dropping off or picking up cargo that would be impossible to transport any
other way. The Rain Forest Tram in Costa Rica, for example, was built to take
people sightseeing through the different levels of the canopy of the rainforest—a
trip that would be impossible with any other type of vehicle. The Palm Springs
Aerial Tram was constructed to take people from the heat of a California day to
the top of the snow-capped cliffs of Chino Canyon while they experience a 30-
degree temperature change (read technical details and see photos of the Palm
Springs Aerial Tram at www.pstramway.com/history-tech/technical-detail.html).
The LEGO Aerial Tram can be customized and programmed to perform
many tasks and respond to sensor input. The basic tram design is powered by
one motor, which moves the tire over the cabling wire from which the tram is
suspended. To create the tower supports and cabling necessary for the tram to
fly, tie a medium-gauge wire (22-gauge works well) to the ends of two chair
backs, placing books on each chair as counterweights for the tram (or substitute
two other suitable tower supports to suspend the cable wire). There are two
ways to power a tram. One method is to power and move the cable, allowing
the trams to move with the cable. Another method is to attach a pulley or
wheel to the tram, powering the pulley with a motor so that the tram traverses
a stationary cable. The LEGO Aerial Tram is powered in this way. A gear is
attached to a motor shaft that moves a tire along a stationary cabling wire.
There are two touch sensor bumpers at each end that can be programmed to
beep, pause, and reverse the tram’s direction. A light sensor is mounted on the
main cab and can be programmed to control the tram’s movements over the

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