Concentric Revolve Ideas

[Mark Amber]

I am an undergraduate student. I am doing some research on concentric revolving stages (not to build one, just to learn). Does anyone have plans for a revolve with two or more concentric parts that rotate freely? It would be very nice if I could see to understand exactly how one could be built and (with permission) use it as an illustration.

 

[Les Engineer]

I am an undergraduate student. I am doing some research on concentric revolving stages (not to build one, just to learn). Does anyone have plans for a revolve with two or more concentric parts that rotate freely? It would be very nice if I could see to understand exactly how one could be built and (with permission) use it as an illustration.

Hi Mark. I'm considering building one myself, and have been consulting with a couple of wise guys on various methods. We're just beginning, so I don't have much to add, yet, and it'll be year before we use the danged thing anyway - then and only then will we know its value. One of our plans is to build the revolving platform so that the outermost and innermost circular planes revolve clockwise while a central circular plane revolves counter-clockwise. Of course, since we work cheap, old car parts are probably in the mix!

 

[BillConnerFASTC]

As a permanent install in a building or as a set piece for one show? and duration of show?

 

[Les Engineer]

Bill, I'm not sure about Mark, but I'm building a one-show piece, and the show is short - maybe 10 performances, tops.

 

[BillConnerFASTC]

Deck and support seem the easy part - I lean toward the wheels fixed on floor and revolve floating on them. If moise were an issue, would have to look at steel wheels on steel rail. I'm not sure about current air caster technology - last I used them they tended to "burp" (polite term) so not ideal for noise.

Drive options are interesting. Does the show require infinite revolution or is it limited to say one or two revolutions? Today I'd look at a cog and race system I think. I was amazed how the wagons were propelled at Covent Gardens operahouse - with races on the edges and spur drives.

The fun part of being a td for sure.

 

[Les Engineer]

Cog and race! That phrase got the old noggin' jumpstarted this morning. I'll check it out. I also perfer the casters on the floor, especially since this is a one-shot up and down, not to be reused, IF the stage manager allows. The "noise" for this production is actually a plus, and I've been looking at what I might do to the revolve to create a certain sound effect passively as the wheel spins (once I know what I want that noise to be - I'm also the "Artistic Director" on this project so I get to have it all!! [evil laughter.] I'm also going to look carefully at your other notes and see what I find, especially the races on edge and spur drives. Thanks!

 

[BillConnerFASTC]

Probably use a roller chain for the race is most economical and reusable. Use a double wide and anchor simply onto perimeter of revolving decks (stressed skin?) and DC stepper motors?

 

[Footer]

Do a search for "doughnut revolve". That might get you closer.

 

[Mark Amber]

As a permanent install in a building or as a set piece for one show? and duration of show?

The requirement was that it had to be put in one of the theaters here, so not permanent. A show run here is usually two weeks, but the idea is to learn how to build something well, so something that will only work for the duration of a short show would be undesirable.

 

[BillConnerFASTC]

Well, what show duration do you want it planned for? Want it to designed to run 10 shows a week for a year? That kind of suggests that the budget is not so important and certainly not in line with a two week run before strike. When I work on high schools, unless clearly stated, I assume the building is a 50 year building max. Buildings constructed for a worlds fair is a 1 or 2 year building. A major civic pac - maybe it's a 100 year building. All should be considered in planning and design is all I'm saying.

Yours is welded steel tube frame decks with rolled steel rails and flanged wheels, and a I'd still look at a race but would use machined steel instead of roller chain and I would look at hydraulic motors because they generally have less maintenance and are quieter imho. Probably 5 to 10 X the cost - or maybe more.

 

[Mark Amber]

Well, what show duration do you want it planned for? Want it to designed to run 10 shows a week for a year? That kind of suggests that the budget is not so important and certainly not in line with a two week run before strike. When I work on high schools, unless clearly stated, I assume the building is a 50 year building max. Buildings constructed for a worlds fair is a 1 or 2 year building. A major civic pac - maybe it's a 100 year building. All should be considered in planning and design is all I'm saying.

Yours is welded steel tube frame decks with rolled steel rails and flanged wheels, and a I'd still look at a race but would use machined steel instead of roller chain and I would look at hydraulic motors because they generally have less maintenance and are quieter imho. Probably 5 to 10 X the cost - or maybe more.

I'm sorry I was not very clear. I am not actually trying to design one of these, but if I was it would be something that could be used for a short run of a show and used a few more times over the next 5-7 years. I was thinking that metal would be the way to go. The main problems I have to address with building a double concentric setup is in keeping the outer revolve in a circular rotation even without a center axle.

 

[BillConnerFASTC]

I'm sorry I was not very clear. I am not actually trying to design one of these, but if I was it would be something that could be used for a short run of a show and used a few more times over the next 5-7 years. I was thinking that metal would be the way to go. The main problems I have to address with building a double concentric setup is in keeping the outer revolve in a circular rotation even without a center axle.

Flanged wheels on steel rails. Easy to google. I think I'd start with the "V" groove that rides on an angle in the Z axis but need to look at friction on a curve and the radius. SImpler - like on a stressed skin deck floating on casters - would be a rim - perhaps inset - and guide wheels - or maybe just UMHW guides. Of course they could be guided off each other - axle on center, and wheel guides on next ring against center section and so on.

Noise, speed, other uses later, might all affect this. *' center and 4' rings - 24' diameter overall?

 

[Les Engineer]

I'm sorry I was not very clear. I am not actually trying to design one of these, but if I was it would be something that could be used for a short run of a show and used a few more times over the next 5-7 years. I was thinking that metal would be the way to go. The main problems I have to address with building a double concentric setup is in keeping the outer revolve in a circular rotation even without a center axle.

You might also keep in mind, Mark, how to take it apart for storage, since you're thinking of a unit that would probably be removed and put away at the show's end. There are several sites out there to help you make a choice on how to do this. We're thinking of it, too, and might opt for aluminum framing in a pie shape with a plywood base that's lightweight and can be stored in our very small "warehouse," (if I can call a large room a warehouse.) Another option is to use squarish platforms with casters attached to the platforms (be careful what kind of casters and how they're mounted) that let you take the revolve apart and use the individual pieces for other shows.