A lever keeps the marble until the elevator lowers.
Instead of a two stud wide track - two beams a space of one apart can
Building everything upside down makes for smooth tracks.
can also be made from the Simple Motorized Machine set.
can be made with the motorized mechanisms blue set.
can also be made with chain links. Motion can be programmed with WeDo tm Elevator
can also be made from Duplo Tubes and Balls.
many conveyor belts or marble walker
and get marble to go up by elevator or pneumatics.