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Turn tables have been used in
theater for a very long time. They allow for quick scene changes. They
can be effective in adding movement to the show. On Broadway, a great
example of turn table use is in the musical, Les Mis. They use the
table to allow the actor to walk, but stay in one place.
The
most interesting turn table I've worked on is the one built into the
stage at Radio City Music Hall in New York. The turntable is built
across three elevators. All three elevators must be at the same level.
Click read more for more!

A
turntable is simple to make and to operate. It can be any size and
shape. Round is the most popular. The one on this page is 4 feet
square. You can also take a look at a turntable during the building process...
What's needed for a turntable?
- A platform, any shape.
- Wheels.
- A pivot point.
- A method of keeping it from wandering off the pivot point.
- A drive. This can be hand driven or motorized.
- A method to stop it from turning. A brake and/or locking device.
let's
start with a basic, round turntable. The pivot point is in the center
and the round platform doesn't need to move anywhere else on stage. On
paper, we start with a drawing of a circle. We add the required framing
for the platform. We need to figure out the locations for all the
wheels. We would use straight casters for this. The shaft of the caster
must be aligned with the pivot point. This is very important! Each
caster will be traveling on a continuous curved line that doesn't
change.
If you were to use swivel casters, it would be harder to get the turntable to turn in the reverse direction.

To see a larger, more detailed and less blurry version of the board, click on it...
Photos of the actual platform. Click on a photo to see a larger version.
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When
you want to have a platform revolve around a single point, using a
center pivot point is the way to go. This is easy to do. you can use
flanges from you theater supply house. Or, you can also use a flange
from your local plumbing supply house.
The one seen here is called a
Key Clamp flange. Why is this a better choice? The pipe is locked into
place via a set screw. This flange does NOT need threaded pipe. The
plumber's flanges does need threaded pipe.
The pipe is locked
into the bottom flange via the set screw. The set screw of the top
flange, mounted on the bottom of the platform, is left loose. This
allows the unit to turn freely.
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We used black tie line to turn this small unit. for larger turn tables, a metal cable would be used.
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How
do we figure out the angles for making this circle of wood? Think about
geometry. A circle has 360degrees. Let's say that our wood circle has
20 sections. 20 little tri-angles. 360 divided by 20 = 18. So, the
bottom of each triangle has 18 degrees between the two bottom corners.
We now need to divide 18 by 2, one for each side, and we get 9 degrees.
(Actually, we will get 90 degrees minus the 9 degrees. Therefore, we
must make a 9 degree cut at each end of our piece of wood.)
Do you want to double check our figures? 20 seams, 2 sides each seam. That's 40 sides. 40 x 9 = 360.
In
the photo, you may have caught that the sections are a little off.
Well, we goofed. We cut the sections a bit too long. Since we had just
two hours to make this platform turn, we had to be creative right there
on stage.
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