Vertical blinds cyc

[Ella]

Hiya

Working on a project in France which is going up on the 2nd of April. I want to create an effect where, at the back of the stage, where the cyc would be, I'm going to rig long strips (vertically) of material, on individual bars. These bars would be attached, I'm thinking, with a scaff joint, to the fly bar, and so able to rotate individually to create an effect like venetian blinds.

 

It's pretty much like normal tabs. Except that I want to be able to control the rotation from offstage... I imagine with a cord running the width of the stage attached to the individual bars (again, like blinds), and then a pulley so it can be manipulated from ground level. I looked up how venetian blinds are made and its a complicated system of gears in each strip... Anyone got a simple idea of how to do this?

 

The other part is the material. The "blinds" need to be transparent enough to see the actor's shadows when stood behind the cyc, backlit, but solid enough to turn in one smooth motion without too much flapping about. In addition, there will be front projection onto them too, and I was thinking of the flaps you get in the supermarket freezer section but apparently plastic doesn't take the image very well. Any suggestions?

 

Cheers ;)

 

PS the flaps would each be about 1m wide, and 4m long, and the width of the stage is 8m

[GridGirl]

Do you want each one to be able to rotate by itself, or do you want to pull one string and have the whole lot rotate at once? If they're individually controlled then it's not too difficult! Each "flap" would need a piece of something solid across the top (wire, bamboo, narrow piece of MDF - like a batten in a sail I guess). Get some appropriate string/line (I'd probably use sash cord) and attach to one end of the batten; run it through a pulley which is at the opposite end of the flying bar to the control end, run the string to the near end of the bar and through pulleys to get it to ground level, back through more pulleys to the bar and then attach to the other end of the batten. That way you should get 90 degree rotation without too much difficulty - if you need 180 degrees it's more complicated and to be honest I don't quite know how you'd achieve it!

 

If they're not individually controlled then it's more difficult but still do-able. I think if you were to do the same thing but instead of attaching the string to a single batten you thread it through an eyelet on each one, tying a knot (bigger than the eyelet) on the opposite side to the direction of the movement, and just tie the ends of the string together to make an endless loop, it might work. I haven't tried this exactly in this way, but I've done something similar and it worked. Good luck, and let us know how you get on!

 

In terms of the fabric, we had a similar issue where we needed something to bleed through like a gauze but hold projection rather than giving the double image you get with gauze, and we ended up with something Lycra-like which worked very well - not sure exactly what it was but hopefully that gives you a starting point.

[GRisdale]

<conspiracy>I glanced this topic last night and I'm sure that there were already several replies...</conspiracy>

 

I think GridGirl's method is about right, but personally I would think it less complicated to make them all move together than individually! For individual control you would need eight individual lines twice (one for each direction), all managed not to snag each other and be able to be move singly or simultaneously without the operator(s) getting utterly confused...

 

I would suggest that you have them all connected, preferably by a rigid link - such as light studding. You might want to consider flying in two bars and spanning them with short scaff bits, with your venetian contraption in the centre - will give you more of a "grid" to work on. Ideally, the rotating arm at the top could be repeated on the floor to eliminate twisting and anchor them down.... You will see a lot of twisting whatever material you use. If you have the budget, consider making hard flats, but remember if you do that your swivel and control mechanisms will need to be able to cope with the momentum of all those flats coming to a stop...

 

Plastic sheeting is not a great projection surface at all. You get very little reflectance and inevitably the surface is very creased and wrinkled.

 

Metal conduit would be a more rigid alternative to bamboo. You will need to think carefully about the swivel points in terms of ensuring they balance. Check out Hall Stage "Swivel Action". Not ideal in their standard form as they have an adjustable locking system, but I'm pretty sure they'd make you some without. Alternatively it shouldn't be too hard to improvise something based on some scaff couplers - but again: balance is crucial. Even a one degree slant at the top will be very noticable at the bottom - especially with eight of them next to each other.

 

For a more "high tech" (stupidly expensive) solution there are things like Robe MediaSpinners offering DMX controlled swivelance.

 

Gareth.

[Pattern123]

Depends a lot on your budget, I would say that getting anything like fabric to hang nicely and form a flat 'wall' at that width will be difficult. I have flown individual Banners in this way on stage for events and they do work if the banner fabric is rigid enough, or if there is a seam down each edge - but obviously if not sat side-by-side then a slight 'scallop' to the edge along the length isn't too much of a problem. I'd suggest have a chat with a friendly banner/sign maker and see if they can suggest anything translucent. Otherwise you might need to make it out of Rosco twin white or Polarcoat, both will be expensive, but with a pocket top and bottom (This would be the difficult bit with either of those surfaces - would need 'welding') you might just get away with it without too much 'scalloping' towards the centre of the drop. Getting them to turn nicely shouldn't be too tough, put scaff top & bottom, with swivel couplers and a line along each end (Plastic end cap with an eye bolt through it glued in should work) tie black line on through one eye at a time when they are 'open' and run through a pulley each side of stage with one side doubling round back to other side of stage to make a hanging loop on one side of stage pull loop like tabs keeping tension on both lines at once (Tab weight?) and it should work. You can mark the line to get settings or judge by eye from wings.

[w/robe]

I think that this is one of those things that sounds easy until you get it up there and then you find you are trying to turn all the sections at once but you have no leverage as you are pulling almost directly along the line of the cyc. once you are half way through the turn it will be easy but the initial movement could be very hard.

 

If they are not too heavy you could hang them on cord fastened to (not just hung over) a scaff bar so they are hung on a loop of cord almost like a picture on a hook, they should then swivel easily and you just tie off the control line to keep them in place.

[Just Some Bloke]

<conspiracy>I glanced this topic last night and I'm sure that there were already several replies...</conspiracy>

One post which was there last night got removed by the moderators on Quality Control grounds as it added nothing to the discussion. Be warned people, this will happen to you too if your post is pointless! ;)