Slewing rings from igus help add lively component to 3-metre owls

The two Kempelen's Owls will soon be part of the Austin Artspace. Visitors can use a hidden mechanism to turn the owl head. (Source: igus)The two Kempelen’s Owls will soon be part of the Austin Artspace. Visitors can use a hidden mechanism to turn the owl head. (Source: igus)

Interactive owl installation becomes a meeting place in Austin, USA

Later this year, a work of art will enrich the vibrant cultural landscape of the US city of Austin, Texas. The interactive sculpture, Kempelen’s Owls, will feature two Texas great-horned owls, each standing three metres tall and perched atop dodecahedrons. Lubrication-free and maintenance-free slewing rings from igus provide a surprise for the visitors.

The “Kempelen’s Owls” are inspired by the machines of the inventor Wolfgang von Kempelen of the 18th century, and are permanently installed only a few steps away from the Austin Public Library and a bustling shopping district. 

“People will say ‘Meet me at the Owls,’’’ suggested Dan Sternof Beyer, founder and creative director of New American Public Art. 

The multi-disciplinary studio conceptualises, designs, fabricates and installs interactive projects. Each owl will sit upon a dodecahedron, a geometric shape with twelve flat surfaces. Kempelen’s Owls has a hidden mechanism that will allow visitors to secretly turn the heads of the birds. 

“The mechanism is hidden in plain sight and readily accessible,’’ Sternof Beyer added. “This will provide passers-by with some surprises.”

Slewing ring bearing from igus moves the head
The central component of the work is a slewing ring from igus, the motion plastics specialist from Cologne. It makes the rotary movement of the Owl’s head possible. The PRT-01-300 ring is maintenance-free and lubrication-free, and has a high load capacity and high wear resistance. 

“The bearing that spins the head of the owl is one of the most important pieces of the project, physically and conceptually,’’ Sternof Beyer explained. “We had very specific requirements: The bearing had to be very wide so that the mechanical and lighting elements could pass through it. This bearing needed to support a large axial and dynamic range to be as safe in public as possible and be as maintenance-free as possible despite various weather conditions. These specific quality requirements have already eliminated the bearings available on the market by 90%.” 

The sliding surface of the igus slewing rings consists of the polymer iglidur J, which is characterised by good chemical resistance, vibration dampening and low moisture absorption. The ring has an axial static load of 27,000 newtons and an axial dynamic load of 7,000 newtons. 

He continued, “The large outside diameter (450 millimetres) allows for less cantilevered sculptural material and the large inside diameter (430 millimetres) allows us to pass through fibre optic cable, which light the owls’ eyes at night.” 

Slewing ring bearings from igus are used in an assortment of industrial applications. They have been used in a handling system for a semiconductor carrier, a self-rotating light, an automatic welding plant and a machine tool control panel, for instance. They are also used in a variety of industries, such as medical, packaging, food processing, solar, seating and material handling.