Hobbies And Interests
LEGO Trains
The earliest LEGO 9V motors were used in LEGO Train sets. Using a simple gear reduction configuration with the included LEGO gearbox, the motors powered the engine cars of each train. If you have access to LEGO rails and the correct wheel platforms, it is possible to mount the gearbox sideways so that the motor's shaft turns a gear that turns the axle's gear, providing drive to the large rear wheels. Building LEGO Trains by the official instructions is the way to get the most use out of the 9V motor in a train design.
Motorized LEGO Cars
A 9v LEGO motor can be easily made to work with an existing LEGO car set by removing the panels on the underside of the chassis and mounting the motor with its gearbox adjacent to the rear axle of the car. When the gearbox spindle and the axle are equipped with gears and aligned correctly, the motor can be used to power the car at a steady rate forward. A simple wheeled platform can be designed to work with the LEGO motor as well, allowing the possibility of having the axle and the engine mounted above the chassis; this allows the car to ride lower, and can even allow for LEGO-scale creations that are compatible with mini-figures.
LEGO Mindstorms
The LEGO Mindstorms sets allow LEGO enthusiasts to make robots that can execute programs to perform complex tasks. The Mindstorms kits can also allow for remote control of connected LEGO motor systems, enabling more complex movement, such as steerable vehicles. With a little bit of practice, a hobbyist can learn to program LEGO Mindstorms by hand and make items such as a replica of a mechanical 2-legged walker from "Star Wars."
Other Projects
LEGO is a creative tool, allowing for nearly limitless possibilities. There have been many large projects that use LEGO motors to some degree, such as a LEGO pinball machine, a LEGO vending machine and a LEGO disk thrower.