"Wizard's Run" is my latest big rolling ball sculpture. It is 77 inches tall, and uses 5/8" steel balls. The balls are constantly being lifted to the top, where they wind their way down twisting, spiralling tracks, occasionally leaping into the air off of the tracks and performing some tricks on the way down. Switches at the top direct the balls to 5 different paths going down, but in two places the balls go back up, and then continue down on other tracks. The magic carpet carries one ball up, and the wobble lift brings up two more.
The tracks are made of stainless steel wire 0.102" diameter, and TIG welded. There are insects and spiders made of brass and copper, and mechanical devices made of brass. Four microcontrollers (computer chips) orchestrate the movement of all of the electrical components.
There is a small stage where a ball rolls in from the back, and the stage lights up with color changing lights. The track drops down, leaving the ball suspended under a magnetic field. It then flies out to the right and goes onto another track. There, it lands on a train car to get carried away to dump the ball off elsewhere.
The train car is powered by a Stanton Drive, which is a small HO train motor that has electrical pickup and power on all 4 wheels. One wheel has a connecting shaft mounted off center to move the pumping arm and the little bugs that pump it.
A magic carpet carries the ball up at one point, to put the ball into a series of 4 chutes that launch the ball through the air to the next chute. It is controlled by a stepper motor, cranking a trolley up a track using fishing line and counterweights. There are ball bearings almost everywhere, for minimum friction, and maximum smoothness of the motion.
As the carpet goes up, it rocks back and forth, and when it gets to the top it rocks forward even farther to tip the ball onto another track. The stepper motor that drives the movement trolley also causes the rocking, through a series of gears driving a pulley that changes the distance of pull on the rocking control line. Without the gears, it rocks back and forth too fast, with the gears it has a slower movement similar to a "real" magic carpet. Magic carpets are real, aren't they? ;-)
The wobble lift brings two balls up, by picking each one up with a claw. The claw is on a small arm that pivots up and drops the ball into the next claw. Three claws bring the two balls up to another track. The way this works is hard to describe, but in the video a picture is worth a thousand words.