revlolving flats

[Thane]

Hi guys

I have gained some valuable tips from this site recently. (how to make real rain on stage )

But now I have a new challenge to make a three walled room at 5 m x 5m where all three walls comprise of 1250 flats AND they have to rotate 180 degrees at many times in the show.

I have a number of ideas but don't want to reinvent the wheel...

Would love some words of experience.

I have some time for this for a change, have thought about many options but would like to keep it low tech as possible.

Any advice would be appreciated.

By the way I am on holidays at present and a bit drunk so excuse any vagueness.

T

[paulears]

So your scenery is made of thin 12cm slats, like those rotating periaktoidal style advertising hoarding? So many of them mean that constructing them is going to be a major job, not because of complexity, just sheer numbers. Conventional chain drive with that many would mean considerable friction, so maybe individual synchronous motors? However, keeping them in sync would be tricky. Maybe stepper motors, but again, you're then into control electronics. Two sided seems on the surface to be a bit of a waste when the usual 3 sided ones offer more scope for the same money?

 

Perhaps when the booze has worn off, you could let us know a bit more?

[bruce]

Sounds a bit like vertical blinds.....

[jimbo7744]

where all three walls comprise of 1250 flats

 

I think the OP means and I read this as 1250mm flats, otherwise if there were 1250 panels, each flat would be 12mm wide?

 

Jimbo

[bruce]

That's the problem with making posts when you've got a drink in you- nobody can be sure what you're talking about...

[Thane]

Ok thanks guys I'm back sober with more detail.

 

I have to build a three walled room 5mX5m. The flats are double sided and need to rotate 180 degrees throughout the show to create two different rooms.

The designer has not provided drawings as yet but has asked for them to be like vertical Venetians. I will push for the walls to be divided into 2x 2500mm panels for simplicity (he wants them divided into 4x1250mm).

The room sits on an 800mm high rostra with the walls flush with the outside of the rostra, thus all my rotating mechanism has to be inside the rostra below or above the flats.

All three walls have to rotate at once and be operated by the ASM from one point back stage.

I have considered bike chain and sprockets but this is going to be rather complex, so to will pneumatics and or hydraulics.

My experience tells me to keep it as low tech as possible but the physics of the thing makes a simple lever system difficult .

 

The other issue is how the flats look when closed and trying to hide the joins to create a clean wall. I will be keeping them as thin as possible, probably 2"x1" skinned both sides with 3mm ply.

 

Thanks again for your input I will work it out. I was also just venting my frustration at the lack of common sense some set designers have.

Thane

[Jivemaster]

Well the slat changing advertisement hoardings are three sided and about 150mm wide. They do however change gradually across the hoarding to limit instantaneous load on the drive system.

[andy_s]

to make the edges meet as smoothly as possible you will need to chamfer the edges of the flats. You will then have only 180 degrees of rotation possible, but I guess this isn't a worry as it's what you mention - worth making sure the director is aware of this, though or he / she might choreograph fabulous wall-spinning scene changes. Alternatively, build frames for each panel with the panel edge matching the frame in a concave/convex arrangement to allow for full 360 rotation.

 

I would imagine that any mechanism to move all 12 panels at once is qoing to be quite complex, but using chain and cogs would give you a bit more purchase - moving all the panels at once is going to be quite a heavy pull.

 

I'd tend to agree with your designer about size. the bigger the panel, the harder to start and stop the movement, and the more clear space required in the wings and on stage to allow the rotation.

 

I'd suggest getting some Meccano and working it out in small scale first!

[benash]

Thane,

 

Simplest system I can come up with is to have a pulley attached to each pivot with a cable wrapped around each pulley so they are linked in series. If you close the loop around the room so the cable is continuous, you can get reversable motion without a second set of cables. Just put a big spring in the cable that closes the loop so the cables maintain tension. Beware that your bearings are going to have to deal with whatever load the spring puts on the cable plus a bit more load for friction. Mount the pulleys as close as possible to the bearings to reduce the bending loads on the flat's pivot shaft. You should be able to get everything from your local yacht chandlery. With this sort of system it's not going to be too difficult to have more flats, I'd suggest you make them smaller than 2500, maybe even 500 wide. The bigger your pulleys the less effort to rotate them but the longer your cable will need to be. To actuate them, attach a bit of wood to one of the pulleys and just have the ASM pull it around 180 degrees.

 

As far as hiding the edges goes, you're never going to get it perfectly flat, if you can work some vertically striped wall paper into the design you might be able to hide the cracks.

 

PM me if this doesn't make any sense, I'll send you a drawing. None of what we're talking about is sufficiently difficult that you couldn't make it at home with a band saw, drill and the usual tools. If you can get access to a metals lathe, even better.

 

Ben

[boatman]

This sounds like a good application for 'Lazy Susans'. They're only 10mm high and are stocked by Flints in the UK. Your local theatrical chandlers in Sydney should have something similar.

[benash]

This sounds like a good application for 'Lazy Susans'. They're only 10mm high and are stocked by Flints in the UK. Your local theatrical chandlers in Sydney should have something similar.

 

Just be careful, often these only have thrust bearings and won't handle big radial loads. Depends on the model and what you're using to actuate the whole thing. I wouldn't be surprised if you can get a small pillowblock bearing for about the same price. All completely dependent how you're going to put it all together.

 

Wish we had a shop with a range like that in Perth.

[Roderick]

Why don't you pop across the road to the Opera Centre?

Have a chat to Duncan (Workshop Manager), he is a nice guy with a wealth of information and solutions.

[DonkiDonki]

 

Probably not exactly what your after but quite fun anyway. I'm surprised the polystyrene didn't get too hot that close to the lamps though.