Design Solutions


Unusual challenge at UNESCO site near Prague’s Old Town

Published: 18 November 2014 - Marianne Evans

HepcoMotion, a global provider of linear and rotary motion, is girding itself for an exciting new challenge a world away from its traditional automation applications. Its HDRT rings have been singled out to feature in a David Cerný statue of Franz Kafka a stone’s throw from Prague’s Old Town, where they will rotate sections of the installation’s face.

The massive monument has a profile split into 42 rotating layers that will become aligned at a particular moment in their cycle to reveal the famous writer’s face in all its glory. The HepcoMotion rings, made from stainless steel to prevent corrosion, will act as large 1.6 m diameter bearings supporting and rotating each of the layers.

The HDRT ring design incorporates an external vee profile and six high-capacity stainless steel vee bearings for ring guidance. The ring has a gear cut into its internal diameter to provide a rack-and-pinion motor driven solution. The integral gear is highly concentric to the ring vee to ensure smooth precision movement throughout the rotation.

“HepcoMotion was willing and able to deliver precisely the package we were looking for: a reasonably priced high-quality technical solution on decent terms. This 42-ring project was a highly competitive commission,” said Jan Kislinger, CEO at DEIMOS CZ, the company managing the project from start to finish.

HDRT rings are less frictional than conventional large-diameter bearings and require minimal lubrication between the vee running surfaces. This translates into extremely low maintenance so the layers can rotate continuously for extended periods.

HDRT rings are available in diameters of up to 1.8m in both standard and stainless steel, with capacities in excess of five tonnes.

Link to sculpture construction:


Industry Connections: HepcoMotion

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