All the world's a stage - and it needs moving

The Unidrive has become the motor drive of choice for companies responsible for the precision movement of theatrical and concert scenery and equipment such as Kinesys and Unusual Rigging.

The UK has, over many years, developed as a centre of expertise for stage and film production, with companies such as Kinesys of London and Unusual Rigging of Northampton being at the centre, directly responsible for the precision movement of scenery and equipment on stage and providing the expertise for spectacular stunts on many films, including the latest James Bond and Harry Potter movies.

The choice of drives in many of these difficult, high precision - and potentially dangerous - applications, which are under the scrutiny of thousands of people in a theatre or arena - or which have a one-shot chance in a film stunt costing millions of pounds - is frequently AC drives from Control Techniques.

This is because, in the words of Andy Cave of Kinesys: "Control Techniques Unidrive SP gives us more flexibility in use than any other make of drive and allows onboard programming, a choice of communications options and, above all, total reliability, which is crucial with the short turn-around time between shows, where everything has to be dismantled, packed, shipped and rebuilt, often in a matter of hours".

Cave recalls last year's Robbie Williams "Weekends of mass distraction" tour, with 18 dates in 10 countries and rounded off at Knebworth in the UK.

Producing set design and an automated video production to complement the shows was a massive undertaking, with Kinesys providing the technical expertise and equipment necessary for the focus of the set - a huge eight-section video screen.

At the heart of the control system to move the eight-column 14-tonne LED video screen around a 360-degree oval track, all in perfect synchronism and each precisely positioned, were eight Unidrive SP AC drives from Control Techniques.

In order to ensure a high quality overall picture when the screens were brought together, millimetre-precise movement was essential.

The reverse sides of the screens were lined with lights, so a rotate mechanism had to be included to allow either the screen or the lights to face the audience at any location around the track.

In conjunction with set builder Brilliant Stages, automation experts Kinesys supplied a total of 30 axes of motion control including eight fixed speed drives to rotate the screens and 14 variable speed chain hoist controllers provided the pinpoint accuracy and speed control for the raising and lowering of the screens - almost touching the floor when downstage and raised to be visible over the band when upstage.

"With Unidrive SP, we particularly like the facility for multiple plug-in modules for very substantial onboard programming and a wide choice of communication options", says Cave.

The system used Kinesys' Vector PC software package, with a Control Techniques OPC server that talks directly to the drives via CT-Net.

The motion control package supervised all 30 axes, providing the essential synchronising and safety features required to ensure that all eight columns could work safely together in such close proximity.

Each of the 7.5kW Unidrive SP drives was fitted with an SM-Applications module, which gives CT-Net connectivity and also additional processing capacity.

Each runs a modified version of Control Techniques' LiPoS linear positioning software, to give greater accuracy of positioning over distances of over 60m and up to 320m.

The strength of LiPoS is in its flexibility, that allows preset or serial communication controlled moves, in discrete, triggered or automatic sequences, as well as continuous following, giving the customer a wide variety of control options.

At any one time, all of the 30 axes could be in movement, with the Vector PC controller giving each LiPoS module target position, speed, acceleration and deceleration ramps and run command.

All the Unidrive SP drives are rack mounted in sets of four, for fast connection and dismantling between shows.

The Rolling Stones' "Licks" tour, a Mark Fisher production, encompassed three sizes of venue, from 60,000-seater stadia, smaller arena shows band and intimate theatre and club venues with an audience of 2000 or fewer.

This presented quite a challenge to the show designers who devised a multilevel modular approach that could be adapted to each venue.

Cave was given the job of designing the control systems for the on-stage backdrops, video screens and lighting pods.

The stadium show opens with a huge back-drop, a 25m-high Jeff Koons billboard, a giant piece of reflective art, divided into 15 printed vinyl panels, with eight vertical slots for "flying lights".

In addition, eight individual high intensity LED screens can be physically relocated to form different shapes and patterns.

Kinesys was tasked with the precision positioning and control for all of these, again using rack-mounted Unidrives.

The system allows for millimetre precision positioning and variable motor control for speed and ramping.

Touch-screen programming allows the show operator to install cues quickly for the 30 axes of movement.

"All of our equipment is rack-mounted for ease of handling", adds Cave, "and is specifically geared to Unidrive".

"There isn't another drive in the market that can provide us with the facilities that we need for these complex control systems".

"We have to maintain flexibility throughout as programming is constantly changing right up to the last minute - and, in this instance, we have the additional complication of three levels of shows, with different requirements for each".

To stage Peter Pan at The Royal Festival Hall, the concert hall had to be transformed into a theatre for the duration of the run, with all of the effects that one associates with a sophisticated show.

The company responsible for the remarkable achievement was Unusual Rigging of Northampton, the same company behind many of the spectacular effects at the Commonwealth Games, the Queen's Golden Jubilee and countless other shows and films.

Perhaps the most memorable moments of the show were the soaring flights of Peter Pan across the auditorium, landing on the edge of the upper circle and back to the stage.

This spectacular effect was achieved with a pair of bridles and winches under the control of variable speed drives from Control Techniques.

Two winches, driven by 11kW Unidrives powering Unimotors, with sin/cos feedback, were used to create a pair of bridles, each with two wires that attached to the four-point waist pickups on the performer's flying harness via short "stingers".

Unusual Rigging designed a control system where the winches were linked and incorporated dynamic load monitoring so that the tension of the cables could be monitored in real time, to ensure the complete safety of the actor.

Each drive was fitted with a plug-in coprocessor that allowed onboard programming and gave communication between the drives to the controlling PC via high-speed CT-Net.

Once the "profile" of the flight was worked out, using a joystick controller, it was programmed into the plug-in modules and the drives were digitally locked together to give a repeatable x-y profile, accurate to 1mm.

The feedback from the load cells monitoring the wire loading was constantly monitored within each drive, with maximum limits being lower at the initial lift and increasing during the highest part of the flight profile, when the wires are in tension against each other.

Although capable of achieving a faster speed, the system runs at a maximum of 2m/s, transporting Peter Pan across the audience in a little over 15s.

"Essentially, we move things, we suspend them and we lift them", says Paul Taylor of Unusual Rigging.

"A lot of our work is creating structures, but then we use winches and cables to create the effect required by the client".

"This is achieved with trusses assembled in different ways and the same applies to the drives systems that are needed to create the required movement".

"We started some years ago using Control Techniques Vector drives and we have now standardised on Unidrive".

"All our drives are rack-mounted for ease of movement and fast assembly".

The Queen fantasy musical, "We will rock you" in London's West End has had rave critical reviews for the music, primarily, of course, but also for the imaginative and technically complex stage set.

Set designers were Mark Fisher and Willie Williams with the main electrical contractor being Kinesys (formerly Entertainment Innovations).

Four separate projects were involved.

The movement, using a "Serapid" push-pull chain, of the "High-School colonnade" up and down the stage, the chain-driven movement of the set of the Tottenham Court Road tube station, control of four truck-driven video screens and, fourthly, the control of four "flown" video screens.

"We had to work to a very tight time schedule", says Andy Cave of Kinesys, "and yet retain the ability to make changes right up to opening night".

"So we chose Control Techniques Unidrives throughout, because of their flexibility in use and their ease of programming".

Time and again, the choice for drives in theatres and for rock tours is made on three key factors - ease of programming, reliability (even when drives are repeatedly moved, connected and disconnected) and flexibility in use.

And time and again, the choice has been Unidrive and, more recently, Unidrive SP.

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