Energy chains keep the cameras flying
11 October 2012
Aerial Camera Systems (ACS) is a leading supplier of specialist camera systems to the film and television industries. The company's products – frequently hung from helicopters or tethered helium balloons – also include 'railcam' systems, those track-mounted cameras that can be moved at high speed and with great precision to heighten the viewer’s experience of televised sporting and cultural events.
ACS' systems are either ground based or ‘flown’ to follow the action in a sporting event, or to provide dynamic and engaging views of subjects that are inherently more static, such as stage performances. ACS railcam systems have been deployed on a variety of film and television sets, including those of Harry Potter and the Deathly Hallows, The X Factor and Dancing on Ice.
The design and manufacture of high-performance railcam systems present many engineering challenges, particularly as they must be capable of moving delicate camera equipment at high speed over long distances, while at the same time operating silently and without vibration. And, of course, reliability is crucial – a failure during a live broadcast would be little short of catastrophic and even in the case of items that are being recorded for use later, unplanned downtime is phenomenally expensive.
For these reasons, ACS has been a long-time user of igus dry-running linear and rotary bearings. These bearings, which are manufactured from innovative high-performance polymer materials, offer decisive advantages compared to conventional metal bearings, and many of these advantages are of particular importance in ACS’s specialised applications.
The igus bearings are, for example, much more resistant to the effects of moisture and contamination than conventional products, which is important when the ACS camera rigs are used on location. In addition, the bearings require no lubrication or other maintenance, they have a very wide operating temperature range and, even when loaded to their full design rating, they have a long and predictable working life. Finally, they offer smooth running, even in the presence of contaminants, and they are virtually silent in operation.
Bearings are, however, not the only products from igus that ACS has found invaluable for use in its rail camera systems. Cable connections to the camera are essential to supply power and to transmit video and control signals, but it is no trivial task to arrange for the cables, which are typically a mixture of copper and fibre-optic types, to be carried reliably while the camera is moving at high speed.
After carefully investigating a number of possible alternatives, ACS ultimately decided that the igus energy chain systems offered by far the best solution for these applications. igus energy chains, which like the company’s bearings are manufactured from high-performance polymer materials, are versatile, articulated cable carrier systems essentially comprising a series of links, the pitch of which is very short giving very low levels of noise and vibration. The energy chains can be easily opened and closed so that cables can be added or swapped as required.
In the ACS rail camera applications, the energy chain runs alongside the track on which the camera runs. While this cable support system may sound simple in principle, the application has high demands placed upon it. ACS tracks operate at speeds of up to 10m/s with an overall travel of 100m or more. In addition, the acceleration and deceleration rates are high and the dynamics of the energy chain must complement the motion of the camera unfailingly.
Further, the camera systems are not always used in the comfortable environment of a television or film studio – outdoor applications at sporting events are almost as common and often involve extreme conditions. ACS systems used at recent Winter Olympics events have, for example, been required to operate reliably at temperatures as low as minus twenty degrees Celcius. ACS head of tracks, Malcolm Rogers takes up the story:
“One of the most impressive features of igus products is that they never seem to wear out. We work them hard, often in tough conditions, yet they’re always reliable and they just seem to go on and on. Possibly a contributing factor to achieving this outstanding performance is the excellent advice we’ve always received from igus about how to choose the right products for a particular application and how best to use them.
“For more than two decades igus has been supplying us with superb products backed up by excellent service, and it’s no exaggeration to say that this has made an important contribution. We’re very happy with the company and its innovative products, and we confidently expect to be using them for at least another two decades!”
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