The launch ramp is a simple incline plane (gravity powered) with a motor-driven beam to move the marbles on to the ramp and to the elevator.
The main picture shows the elevator in its ready position between the launch ramp on the left and the exit ramp on the right. In the other picture you can see the elevator in its top position. The marble starts out between the two large angled beams and, as the elevator rises, rolls down, across the light sesor, onto the two straight beams and then on to the ramp.
The heart of this project is the towers and the tubing. Since the tubing exerts alot of stress, the towers need to be very sturdy and reinforced as much as possible. There are several different styles of cross blocks and I used all of them and every one I had. The cross blocks are attached to the upright beams and an axel (usually a 3-axel) in inserted. The ends of the sections of tubing fit tightly over the axels. Legoeducation.com sells two kinds of tubing but I buy mine down the street at the hardware store.