A Periaktoi is an ancient device, often thought to be of Greek origin, that is still used for stage scene changes. It is usually a triangular unit with (3) equal sides. Each side can have a different scene painted on it. When using more then one* Periaktoi in a row, it can look like a solid wall. When all the units are rotated to the second or third side, it reveals another scene. One of the most well known shows to currently use Periaktoi is "A Chorus Line."

*Periaktoi is actually a plural term.
Here is a drawing for our current production of Mame. We will be building 6 Periaktoi columns. Check back as I am taking pictures of the process. 03/06/03...

Our Periaktoi frames are built using plywood tops and bottoms. The middle triangles are custom built from scrap plywood and 1x3 furring strips. The notch is for the 1x4 pine boards that will stand the unit up. We've ordered the lumber at 10 feet.

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The verticals are placed in the notch and then a couple of brads are air nailed into the plywood, through the 1x4 and into the other side of the notch. This virtually locks the piece together. pe3.jpg
Remember to nail the thinner material into the thicker. In other words, we used 1/2" ply for the little triangles and we're nailing through the ply into the 1x3 stock. The staple gets more wood to bite into. Don't forget the glue!!! pe4.jpg
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Since we had to build 12 triangles, we made a jig. I took one of the regular plywood triangles, attached a small piece of ply on each side of the point. Then, we placed the little triangles atop the 1x3 and pushed it into place. Then stapled. Doing it this way made sure that each was the same. I'm sure you've run into a situation where you've tried to nail something in place where the thing you were trying to line up is on the bottom. pe6.jpg
These hollow triangles serve more then just the money saving purpose. If the middle triangles were solid, we wouldn't be able to add the diagonal bracing. Since these units will be soft covered, we need to add the bracing on the inside pe7.jpg
Setting the diagonal bracing properly is difficult. Getting the frame to be square, but in a triangle is tricky. I'll post how we did this after we figure out how! pe8.jpg
We figured it out. how to get these thing to be square before nailing in the diagonal bracing. Looking at the picture, you'll see two red boxes. These are some of our practice cubes. They are already square. We placed one at each end. Clamped the ends to the boxes and screwed the boxes to the table. The side of the Periaktoi is butted up against some wood screwed into the side of the table. pe9.jpg
A forest of Periaktoi. Three units are done and they are taller then the shop lights. pe10.jpg
Laying out the muslin for cutting. This bunch is 9 feet wide by several yards long. I tend to buy damaged muslin from RoseBrand in NYC. The damaged goods end up being half price from the new stuff. The damage? just a few stains. Since we're painting the muslin, we don't care about a few stains... pe11.jpg
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We laid the muslin out on our work table. Then we placed the frame on top, pulled the muslin up and stapled the edge to the wood. pe13.jpg
Before stapling, we ran a bead of glue along the wood edge. While stapling, we pushed the muslin down into the glue to be sure of a good bond. pe14.jpg
Team work is very effective at this point. We don't want the glue to dry before the muslin gets stapled. pe15.jpg
These things ended up looking pretty good. Nice and tight muslin covering is very important to give the unit clean lines and a smooth surface. We still need to size the covering with watered down paint. pe16.jpg
Here we have three of the units standing side by side. Standing like this, they form a wall. Though our design doesn't call for these to be up against each other, we could paint each side to match. This would give us three solid walls of our choosing. pe17.jpg
The rear view of our set of three Periaktoi. Our next steps include: sizing, mounting on turn tables and placing them all on platforms. pe18.jpg
We're sizing the muslin with watered down paint. I like using a 1 to 1 ratio. That's half paint and half water. We use any color that we have too much of. pe19.jpg
We're working on placing rotating bases on the units. pe20.jpg
The turntables need to be installed using a small access hole. This hole lines up with an access hole on the lazy Susan. pe21.jpg
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Safety glasses please! pe25.jpg
 A Periaktoi is a triangular unit which is often made by one of two methods. The method you see here was via building a frame with three styles held together by three triangular pieces of 1/2" ply. One at the top and bottom with the third at the center.

 

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This is a ground plan (top) view of one of the triangular pieces of ply with the 1"x3" furring strips inserted into each corner. Notice that if you were to draw a line from the very outside edge of the 1"x3"s, that line will not touch the plywood. When we cover the unit with muslin, the muslin will not touch the plywood. Thus concealing the framing. It will look just like a soft covered flat. pe27.jpg
This is simply a side view of the assembled Periaktoi. Depending on the height of the unit, you can insert as many 1/4" ply frames as you need.

Why Might you need more 1/4" ply braces? Think about what happens when you size the muslin. As the sizing dries, it shrinks. You don't want the open sections of 1"x3" to bow in. You'd end up with a big hour glass.

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