An art display at the Tate Modern in London is relying on a linear transmission and positioning system supplied by HepcoMotion. ‘Fearful Symmetry’ by Ruairi Glynn features an illuminated tetrahedron mounted to what is believed to be the world’s largest delta robot, creating the illusion of being ‘alive’ within the gallery’s vast darkened tanks. At 21m in length, the DLS4 linear rail from HepcoMotion allows the tetrahedron to traverse across space as it ‘interacted’ in real time with gallery visitors.

“When I first went to HepcoMotion I had little more than an animation,” said Glynn. “The delta robot was in construction and I had a rough idea of weight, but that’s all. I knew HepcoMotion offered the technology we needed, but was unsure of typical delivery time.”

Glynn and his team needed to undertake testing before installing Fearful Symmetry at the Tate Modern, which meant HepcoMotion had just four weeks to supply the linear rail system, gearbox and mounting ancillaries.

The DLS4 system belt-driven linear modules, an AC motor/inverter package, and a range of compact planetary gearboxes for use with servo motors. Options include a cantilever axis with lightweight beam, plus couplings and connecting shafts for units used in parallel. This also has a steel-reinforced polyurethane belt for minimum stretch and high speed capability, as well as quiet, trouble-free operation from proven ‘V’ bearing technology.

Although capable of being quicker, the motorised 21m linear rail facilitates 2m/sec traverse speed of the carbon fibre delta robot, which at 5m in height (fully extended) is thought to be the world’s largest.

Once installed within the subterranean tanks at the Tate Modern, Fearful Symmetry was commissioned and presented to the public for the first time as part of the Undercurrent arts programme in August 2012. The glowing tetrahedron, made from electro-luminescent sheet, glides through the air suspended above people’s heads. As the only light source in the room, the tetrahedron acts as entertainer and guide to the space, dancing with the audience, and playfully encouraging them to become an active part of the performance. This is facilitated by an array of sensors that create a 3D map of the 30m diameter, 7m high space, relaying information to an on-board computer.