motorizing a turntable

athart7

Member
We're doing Les Mis. I've read the posts about building the turntable, but not much detail about motorizing it. What type motor did you use? My turntable will be about 15 feet in diameter. How did you get the motor to turn the turntable without being too loud? Should I use a chain or a tire or some other mechanism? Advice for a first time turntable builder?
 
What is your time frame, how soon do you need to start building it?

Michael Powers, Project Manager
ETCP Certified Rigger - Theatre
Central Lighting & Equipment Inc.
675 NE 45th Place, Des Moines, Iowa, 50313
 
Do a bit more searching, this has been discussed in detail many times.

Its not going to be cheap to do. Any time you have something automated on stage its going to cost you at least 5k if not 10k. If you are not prepared to swallow that cost there are human powered ways.

If you are interested, I know a few people in Cinci that might be able to help you/rent a rig to you. PM me with your contact info/who you work for and I can send that off.
 
It took 18 months to build mine. I wish you the best of luck.
 
Well, July is doable but close, depending on your crew and shop. 15' diameter is a fairly small TT so is it smaller than 2 sheets of ply in both directions and 2 professional level carpenters with proper tools and equipment, should be able to knock it out in 40 hours or less. You can drive it as a rim drive with a tire or a cable/chain drive. Decide on the method of drive before building as the construction of the frame is different. Also figure where the motor and drive will be located on your stage, it might make a difference on the construction if there are obstructions or you need a path for scenery or actors etc. For a 15' TT, running at, say, 4 rpm max, a 3/4 hp should do, 1 hp will be fine. More hp is ok but unnecessary. Spend the money on a good center bearing and have a center shaft and mounting plate welded up at a metal shop if you do not have welding capability in your own shop. Take the time to design or have designed, your drive system, that is just as important as the TT itself and should be the first thought, not the last.

You mentioned noise. The motor is rarely the noise maker. It is usually the casters and the rumble they make. Inverted casters, casters on the floor pointing up are usually quieter.

I know this is a very quick gloss over,hope it gets you going in the right direction. Do check the past threads, they will help you a lot.

Michael Powers, Project Manager
ETCP Certified Rigger - Theatre
Central Lighting & Equipment Inc.
675 NE 45th Place, Des Moines, Iowa, 50313
 
In all serious-ness, don't motorize and get a couple of crew on a winch. I've done Les Mis twice and both times we had a non-motorized revolve and it worked perfectly. It's far more flexible and much less likely to break down, plus it's cheaper and less complicated. We had no problems with just two crew on it - and we had a 9m diameter revolve the first time round.
 
Revolve automation

I know there are plenty of forums out there about revolves but I have a more specific question that I would love feedback on. My high school is putting on a fall production (I am a co-set designer) and we are using a 28' diameter revolve. We would love to somehow automate this with out actually having a bunch of people pushing it. I had an idea that involves a bike. If we were to wrap some sort of cabling around the revolve and then around a smaller wheel and we attach a drive shaft to the wheel and to a bike on a stationary trainer would we be able to move the revolve? Does anyone have any other ideas of how to manually rotate the revolve with out having people push it? any idea is welcome, we would love for what ever we use to be relatively cheap so expensive motors are out of the question (but if you know of cheaper motors that would work please let me know) and we also what to make sure what every we use does not make much noise. Please let me know what you think


The revolve will have scenery on it. Please let me know if you have any questions or need any clarification.
 
Re: Revolve automation

I always encourage out-of-the-box thinking, but my feeling here is probably not. First, engineering a cable, chain, or direct drive for a revolve is no small matter. There are many discussions on all those options on CB. Here's part of one, from yours truly:

"There's a type of winch frame you can make for endless loop GAC (often used for revolves) that use two sets of about 6 sheaves each on separate shafts. One set of sheaves is keyed to a drive shaft, which could be motor or crank driven, and the other set are idlers on the shaft that can be tensioned away from the drive shaft. The GAC loops back and forth between the shafts, creating enough friction to drive the cable. There are instructions in Focal Press's "Technical Design Solutions for Theatre" Volume II."

Here's some more:

http://www.controlbooth.com/forums/scenery-props-rigging/19682-motorizing-turntable.html

Basically, the bike idea could work (although whether one person could drive a 28' diameter is questionable.) It's connecting the bike to the revolve that's the tricky part. If you have a few hundred dollars and LOTS of time, who knows?
 
I've done Les Mis twice and both times we had a non-motorized revolve and it worked perfectly. It's far more flexible and much less likely to break down, plus it's cheaper and less complicated. We had no problems with just two crew on it - and we had a 9m diameter revolve the first time round.

Could you please either post or PM me how you did this, I am trying to figure out how to rotate a revolve we are making and your design is intriguing.
 
..., I did not like the revolve but the rope was interesting. Make a Revolving Stage: How to Make a Revolving Stage
That is truly the most stupidly made revolve I have ever seen. < and I don't just say that because MY plans are THE best > The rope Idea is horrible. If you want to drive a turntable your best options are: A chain in a groove around the perimeter or a Drive wheel on the top or bottom or the revolve which is held in compression with another wheel on the opposite side of the table < sort of sandwiching it between two wheels as it were.
 
Could you please either post or PM me how you did this, I am trying to figure out how to rotate a revolve we are making and your design is intriguing.

It was as Van mentioned in the last post - a chain (well, wire rope in this case) in a groove around the circumference of the revolve. It came off the revolve itself, through guide pulleys mounted on the floor to a point offstage where it went up through more pulleys and onto a winch drum. The two revolves had two slightly different systems - one had a big wheel which the wire rope went round just once, with handles mounted to the wheel, the other had a worm gear (I think that's the correct name!) so there were eight or nine turns of rope around the drum - handles mounted to the drum. The second one was much less prone to slipping which was useful as it was driving a bigger revolve. It also had a smaller diameter rope. There was also the capability to adjust the tension of the rope built into both winches - the winch was bolted to the floor but it had some movement within the frame.

We discovered, after some trial and error, that it was better to have a crew member on each side of the winch with one handle each, rather than yachting winch style with one person facing each way, operating both handles at the same time.
 

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