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Chapter 17 |
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Read: Gerrit Rietveld through The Bauhaus (pages 409-410), and The Forties and Fifties (pages 414-416).
Premise: In this project you will design and build a corrugated cardboard chair. This project will take at least six hours to do badly, and probably fifteen or more to do well! The chair must have a functioning back (back rest), support your weight completely, and use only water-based glue and gummed parcel tape!
It seems hard to imagine that you could build a functional chair from this material, but in fact, it's quite easy. Included are some diagrams that show how a simple chair might be laid out, cut, and assembled. My example is only the simplest of an infinite number of solutions. Over the years my students have built double-seated chairs, rocking chairs, chairs that use no glue or tape, recliners (RECLINERS!), and also...an occasional flop.
You might start by sitting on a cardboard box. You'll be surprised by the fact that although it may give a bit, it will probably hold your weight. Now, what would you do to strengthen it? What are the areas that started to fail? How would you support them? And finally, how would you attach a back?
Here are my pointers (If an instructor is assigning this project to you, he or she may include their own limitations and requirements):
1. Be true to the material—it's corrugated cardboard, the same cardboard they use for boxes. Don't expect to produce a Queen Anne chair, or a lever action recliner through this project. In reading the section on Marcel Breuer, you'll note that he gave great consideration to the type of form that was reasonable and logical to expect from steel pipe.
2. Corrugated cardboard, by nature of the corrugation, has a sort of "grain" to it—meaning that it exhibits resistance to weight in one direction, and bends or folds easily along the other direction. Use this.
3. A triangle is the strongest architectural form using the least amount of material, but in the world of cardboard chair construction, the fully closed six-sided cube is also very strong.
4. Work with the surface strength of the two-dimensional plane. Don't waste time trying to laminate cardboard layers together. Some students try to make a chair back with two laminations of board. It's rarely successful.
5. Cardboard has its own "aesthetic" that has been defined in part by the way we use cardboard. Don't try to paint, decorate or otherwise change the aesthetic of cardboard, rather, worship it.
Time required to do this project: allow 15-18 hours including model construction.
Materials: pencils; ruler; graph paper; one corrugated cardboard "trim sheet," approximately 54" x 99" (available from box companies—look in the yellow pages under "boxes"); a utility knife; scissors; 2"-wide water-base gummed parcel tape*; a 36" aluminum or steel ruler; Elmers® glue (optional); a small ceramic dish or saucer and a small sponge to wet the parcel tape.
How to start: I believe that it's best to start this project by 1) doing a number of sketches, and 2) by building a scale model.
Begin this project by analyzing an actual desk chair. Have you ever measured one? How many inches from the floor to the top of the seat? How wide is the seat? How high above the seat are the armrests (a word of caution—armrests are difficult)? How high is the back? Is the seat parallel with the floor? Is there an angle to the seat and back? Take measurements.
In the classroom, I start with this basic diagram on the board—a sort of "microphysics" of it all. There are three things to remember about the structure—A. the tension created between the seat and back when someone sits down; B. making sure that the sitter's "center of gravity" is directly above a point on the floor inside the chair base; and C. the overall structure must support your weight!
Begin with sketches employing the basic dimensions of a standard chair. You might even sketch directly on the graph paper, anticipating that one square equals one inch. While straight lines are easier to execute with cardboard, curved lines might better address the contours of the body.
It's hard to know if you're doing a good design or a bad design when you first begin. A successful design, ultimately, will be a chair that supports your weight and allows you to lean back without falling over or having the chair back separate from the seat. What else contributes to a good design? Does the chair demonstrate design challenges? Can you lean back and be comfortably supported? Has the designer created a chair that can be made from a single trim sheet without glue or tape—just using cuts, folds, and tabs? Does the chair take risks—does it push the material to its limits?
I started by taking the basic diagram above and using it as the basis of my design. You might start the same way, or like most cardboard chair designers, you might find it too boring.
When you have a sketch that seems plausible, consider how it translates to a pattern—a complex cutout shape that, when folded and assembled, becomes the chair. If you have a sketch on paper of the chair, how does that open up to become a flat piece? Start by counting out squares on the graph paper based on the dimensions of your trim sheet. If your trim sheet is 54" by 99" count out 18 squares one direction and 33 the other. I did my sketch so that 1/4" equaled three inches. Once you have the profile of a design, transfer it to 1/4" graph paper, and determine the most efficient spacing. Below is a diagram of my layout.
Building a Model: (Optional)
I would suggest building a small model for practice, although you can skip this step if you're courageous and confident. Often times, a model will reveal potential construction problems that are going to occur in the actual construction of the chair. It's nice to find out during the model phase. Models can be made from 4-ply poster board, or file folders, which are a stiff, but flexible card stock.
In my layout above, you can see that the sides are marked on the left. I've also made two extra sides. These are filler pieces that I'm going to space evenly inside the chair. If you want to use less tape and have a cleaner look to the chair, try arranging the shapes so that they fold at important junctions (ie: rather than have separate sides and a separate back, you could have one continuous piece that includes the back with the two sides hinged to it.
Whether you build a model or not, you will have to transfer your graph paper pattern to the cardboard and begin cutting. My preferred tool for cardboard is a utility knife with a retractable blade. Once all the sections are cut out, you are ready to begin the assembly. Fill the ceramic dish half full with water, and place the sponge in it. This is essential for wetting the parcel tape.
Outside edges which form corners are the easiest to tape, and they'll hold the form while you attach inside filler pieces. Sometimes it's helpful to apply a small square of tape to "tack" two sections in place before you dampen a long strip that will hold the entire edge. Tape everything inside securely. Glue may be useful for securing inside edges against flat planes, such as the edges of the filler pieces where they connect to the seat and back.
This project, though time consuming, is a great way to learn about designing functional objects, pattern making, engineering, and construction skills! Yes, working with cardboard, like any material, requires some skill. Determining your success is easy...in fact...you can do it sitting down!
Below are two examples of chairs by students from Oregon State University, Peter Yue and Jolene Quiring. (To see the works in their larger formats, click the thumbnail images.)
Left: Peter Yue's cardboard rocking chair. Right: Jolene Quiring's tetrahedral chair. Both chairs passed the sit down test!
Peter Yue successfully designed and built a rocking chair, virtually impossible with cardboard; Jolene Quiring created a beautifully arranged group of tetrahedra that formed legs, seat and back.
*About materials: The materials for this project may be more difficult to find than the other projects. Many cities have box or cardboard suppliers listed in the yellow pages that can either provide the cardboard, or tell you a source. Appliance stores often have large stove and refrigerator boxes that they discard. Call them. The gummed tape is available at most stationery supply shops.
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