A wheelchair stair lift is a device that enables a person who uses a wheelchair to go up a flight of stairs, and it is permanently installed in a stairway. Learn about the motor and chain system that operates a wheelchair stair lift withhelp from a professional carpenter in this free video on home improvement and stair lifts. Expert: Stephen G. Anthony Bio: Stephen G. Anthony is a professional carpenter, woodworker and handyman based in New York City and south Florida. Filmmaker: Paul Muller