Gearing up

Jon Lawson

Graham Mackrell looks at the gearing requirements for broadcast cameras

This year’s IAAF World Athletics Championships, held in London, attracted millions of viewers around the world, all tuning in to see stars such as Mo Farah and Usain Bolt’s final hurrah. The filming of the event had be up to the same standard as the world class athletes.

Harmonic Drive Gears, otherwise known as strain wave gears, are being used at the World Athletics Championships in television camera rigs.

The gears are used due to their distinct features that put them at the pinnacle of gear engineering and make them suitable for the challenges of broadcasting.

Remote controlled cameras, used on rigs, are being increasingly used by camera operatives to capture shots from hard to reach angles or to allow the camera to zip across the track on wires. This is stable, much quicker than a human could film and also solves any security or safety concerns with a camera person high up in a stadium.

To maintain smoothness when filming, harmonic drive gears have zero backlash for their entire operating life. This is achieved by naturally pre-loading the Flexspline into the Circular Spline and ensures that the filming is smooth and without any noticeable stuttering or bumps.

Low backlash is achieved by other gearing methods by tight gear engagement, however this can cause wear on the gear, torque ripple and an increase in noise, which would obviously be unacceptable for a camera capturing video.

There are of course other considerations than motion. Harmonic Drive Gears are extremely accurate, to provide high positioning accuracy for camera pans and tilts, and boast a compact, lightweight design to ensure safety when manoeuvring across the stadium on wires.

With the elite of the world’s athletes visiting London to take part in the World’s Athletics Championships, the elite of the world’s engineering feats must be on hand to support the event. So, when you’re cheering on Usain Bolt’s speed or Mo Farah’s stamina, think of the hardworking gears that are powering your viewing of the events.

Graham Mackrell managing director of Harmonic Drive UK