When the Children's Museum of Utah moved to a new location in downtown Salt Lake City, they asked us to create an interactive sculpture for their atrium. They introduced us to Salt Lake City artist Andrew Smith and we incorporated a number of his pieces in the atrium along with our own. Everything in this atrium can be controlled by kids in a significant way. Andrew's pieces feature bubble tubes where kids make the bubbles and a bicycle rider that kids send back and forth through the atrium using a bicycle pump. Our big gear machines control how light shining into the glassy atrium gets colored by moving giant gels in front of the windows. It is more and more common to find big "atrium art" pieces in public places, but this piece is unique in that all the huge pieces overhead can be moved by visitors turning simple handwheels, and when the pieces move they cause interesting effects in the space. To develop this piece we created a full-sized prototype in our shop and tested it with kids to figure out the right gear ratios and color combinations. We also developed a unique process for creating colored acrylic that has found applications in the scientific and architectural lighting fields.