RSC Lightlock

[Sarah Q]

What did people think of the RSC's LightLock?

 

I saw it in development a few years ago, but didn't get to PLASA to see the finished result... I know it has been nominated for an Innovation Award...

[gareth]

So can someone please enlighten me as to what the RSC's "LightLock" actually is?

 

I've had a look at their web page, but other than that it's a white box that sits in between the moving light and the bar that it's hung on, it doesn't really say anything much. There are, though, some interesting claims on that page - a Tallescope takes SEVEN people to use it safely?! Really?! And how have they worked out that one of these things reduces moving light downtime "by a factor of 150"? And what exactly does that mean? That web page says a lot but tells the reader virtually nothing ...

[J Pearce]

It is a white/grey box that sits between bar and light, and by some form of technology counteracts the inertia from the movement of the moving head so that the head base stays static during movement.

 

Thus, it stops the light swinging long after a move.

[Sarah Q]

So can someone please enlighten me as to what the RSC's "LightLock" actually is?

 

 

RSC LightLock

 

Until now it has been impossible to hang moving lights onto trapezes, lightweight automated bars or pantographs; when lights are repositioned as part of cue sequences unwanted oscillation in the structure would occur. The RSC LightLock is a revolutionary new device which allows moving or motorised luminaires to be rigged on very lightweight hanging or flown structures. Each unit is equipped with sensors to constantly monitor movement and the device generates sufficient inertia to eliminate that movement. The RSC LightLock can be rigged directly onto any structure and can have a moving light attached directly to its chassis.

 

 

(From Plasa website - http://www.plasashow.com/awards/index.asp?id=750661087)

[gareth]

OK, it's becoming clearer. So, how does it reduce downtime by a factor of 150?

[J Pearce]

I think they are referring to the act of having extra movers that aren't used until they stop swinging.

 

So you'd have static movers waiting to be used, static movers being used, and swinging movers waiting to stop swinging.

 

However, I can't see how that equates to a multiple of 150...

[karl]

the device generates sufficient inertia to eliminate that movement.

 

Surely you can't create inertia, it's a property of all bodies. What you can do is create a force which acts in the opposite direction to the one you are trying to damp out.

[andy_s]

just watched the demonstration, and it definitely works.

 

I imagine it's along the lines of "equal and opposite force"...

[Andrew C]

Reckon it's just a gyroscope?

[Bryson]

I assumed it was using a Segway-type balancing algorithm, and moving weights around inside. Clever, though, it's only 7KG.

 

Still don't quite get how it reduces maintainence costs by 150 times, though....

[andy_s]

Still don't quite get how it reduces maintainence costs by 150 times, though....

 

it's not maintenance as such - by downtime they mean the time after a move when the trapeze would normally be swinging madly and you wouldn't ordinarily want to fade the light up , rather than time on the repairs bench. I guess this is cheaper than duplicating the fixture and alternating moves / fades?

[gareth]

it's not maintenance as such - by downtime they mean the time after a move when the trapeze would normally be swinging madly and you wouldn't ordinarily want to fade the light up , rather than time on the repairs bench. I guess this is cheaper than duplicating the fixture and alternating moves / fades?

But the figures are still meaningless without something to back them up. What's their 'reference' that's 150 times less efficient? And I still have no idea where they get their 7-people-to-a-Tallescope statistic.

[Sarah Q]

And I still have no idea where they get their 7-people-to-a-Tallescope statistic.

 

I reckon it's not people physically around the tallescope, but involved in the proecedure.... four at the bottom (on a raked stage like the RST used to have), one at the top focussing, one on the lighting desk calling up channels, and one shouting the channel numbers from the lx plan to the board op

[andy_s]

it's not maintenance as such - by downtime they mean the time after a move when the trapeze would normally be swinging madly and you wouldn't ordinarily want to fade the light up , rather than time on the repairs bench. I guess this is cheaper than duplicating the fixture and alternating moves / fades?

But the figures are still meaningless without something to back them up. What's their 'reference' that's 150 times less efficient? And I still have no idea where they get their 7-people-to-a-Tallescope statistic.

 

I'm not defending the figures as such, merely repeating their definition of "downtime" as the period of time during a performance when a moving light is not "earning its keep" by being available for work, so to speak. I guess you could fiddle the figures any way you like - for instance, if the light was on for 4 seconds, and then couldn't used for 10 minutes, that would be a ratio of 150:1 off to on. (I think...maybe my arithmetic isn't too hot....) Somehow doesn't strike me as a very likely scenario, so I think we can agree there's a certain amount of "poetic licence" involved.....

 

regarding the tallescope - three a side and one in the basket?

[LeeStoddart]

regarding the tallescope - three a side and one in the basket?

 

Regarding the tallescope the article does say it reduces the number of people involved from 7 to 2. This by being able to bring the movers down to stage level rather than have to work on them at height. So does that mean that the two people act as fly crew and then LX and then fly? I suppose that is possible but I think rather like the 150 times improvement it sounds like marketing hype rather than something concrete.