Ball Screw Guides Retractable Wall

Chicago Scenic Studios, Inc. (CSSI) designs and builds television studio sets, exhibits, and special-event stages. When the company was approached to design a set for a local TV talk show, there were several design challenges.

According to Mark Ewing, CSSI head of automation, the set design included a system for vertically lifting and retracting transparent, 300 lb acrylic walls. “The walls are 16 ft high and the studio ceiling is 30 ft high. We needed a means for reducing the height of the wall in half by lifting and retracting the lower portion inside the upper portion. This movement occurs quickly and quietly. We were also working with frosted Plexiglas with double-sided light boxes. We needed to hide the linear motion control system in the upper wall within a very small work space.”

By deploying Nook lead screws. CSSI was able to lift the 300lb walls over a travel length of 8 ft, dampen vibration and resonance, and sustain a 6 ips lift speed.

CSSI turned to Nook Industries for help. Nook proposed specially reconfigured 50 mm ball screws that are mounted in the sides of the upper wall. The system uses an ac motor, which drives a miter gearbox to turn the ball screws raising the ball nut on the lower wall to lift it.

In addition, the retractable wall system had to move the wall at a rate of 6 ips without creating any excess noise, resonance, or vibration. To accomplish that, Nook engineers increased the diameter of the lead screws and used a steep pitch thread pattern.

The set project was on a tight development timeline. Ewing added, “We had no time for trial and error or trying different prototypes. We needed something that worked out of the box and had zero margin for error. Nook’s responsiveness contributed to the on-time, on-budget delivery of this sophisticated, technically challenging project.”

Nook Industries
www.nookindustries.com