I'm an electrician, but I don't know what is normally used to operate a revolve. I'll assume it's a motor with a speed controller, and some sort of friction, or geared drive, to the turntable.

What type of motor operates the revolve - Single phase or three phase? Get as much info from the motor as you can.
Being that old, I assume the controller is operated manually - you start and stop it by a switch, and select the direction??

Do you have any information on the controller - does it have a manufacturers label?

Modern variable speed drives for three phase motors are readily available, , quite small and very cheap, but you need to suit a drive to suit your motor. They are quite simple to run from a remote panel, with the drive located near the motor. If you are more technically minded, you could fit an encoder to the revolve so that the drive knows where it is, which means you could program it to stop in at specific points. Most drives also have a comms input, usually RS485, which means it can be controlled over a network.

There's people out there that know more about what is used in the theatre business than me, I'm sure.

www.meltheco.org.au

http://www.controlbooth.com/forums/scenery-props-rigging/10155-turntable-stage.html

Take a look at this.

Hi There, We are a new company in Sydney called Rotation and we have revolving stages. Our website is: www.rotation.net.au.

Please give me a call about your problems and we will see what we can do to help!!!

Melissa Hawkins
0410 540971
melissa.hawkins@rotation.net.au

There's nothing special about revolve motor controllers, just try your local electrical engineering companies, your old controller might be easily repaired, if it's worked all these years it may be worth repairing.Modern controllers use microprocessors and sophisticated circuitry which is great when it's working but can be harder to fix, old gear uses discrete components which are more readily available.

Sounds like a contactor coil burnt out, or if you are unlucky a motor has burnt out.

Start by getting an electrician to look at the controller and motors, as david has said, sometimes it is worth keeping the old simpler controller going, unless you need your revolve to go to preset points, accurately.