Folded Plate Chair #3B




Introduction: Folded Plate Chair #3B

About: I'm an architect and contractor who enjoys designing and making furniture. In the same way new technologies have developed from toys, building furniture is a great way to explore new structural ideas. Today,...

This is a design for an "origami style" plywood chair. After doing some initial prototypes with various sheet goods and continuous hinges I settled on this design as a good balance of affordability and quality.

Step 1: The Parts

There are many kinds of plywood out there but if you're actually going to make a nice piece of furniture without applying edge banding you really need to make the investment in a good sheet. One sheet of 1/2" latvian birch plywood ran me about $80 and two chairs will fit easily into one sheet. The continuous hinges, which I use to make the folds, are a more cost driven decision. After experimenting with more costly hinges I settled on your garden variety 1 1/2" wide continuous hinges from the local hardware store. A 6' length runs about $15 to $20 dollars and five lengths should easily make two chairs. I used a 3/8" button head screws for the continuous hinge. These are NOT the screws that come with the hinge. It would be nice if I could countersink the screws but it turns out continuous hinges typically countersink the opposite side from the face we use in this project. I've spoken with the manufacturers about reversing the countersink but at this point, big surprise here, it would kill the economy of the project. Thankfully the button heads screws on the backrest are so deep in the "v" of the backrest you don't feel them. I think you should be able to buy all the screws for $20. All of this to say that if you're careful you should be able to make two chairs for less than $100 each. I'm planning on finishing mine in Tung Oil but you can certainly pick any number of finishes.

Step 2: Some Background on the Geometry...

If you decide that you want to use different hinges and plywood be aware that there is a very specific performance criteria to your coupling. Different couplings of hinges and plywood thickness yield different possible shapes. Above are some images showing the dihedral angle limitations of the coupling and the design itself. Notice the hinge/plywood folding capacity is paired tightly with that of the design. In doing this folded plate exercise I needed to reconcile what I could dream up with what the materials would let me get away with. It was fun coming up with a shape that worked with my kit of parts.

Step 3: How It Can Be Made

There are two ways basic ways this geometry can be fabricated.

1) Print out the attached image and make the pieces with a jigsaw and a router. Please let me know if you need something with greater resolution.

2) Use a CNC machine. I've attached the VCarve file here as well. Good Luck!



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    28 Discussions

    Cool idea! I really like the self-jigging concept. For me though, somehow the complex "old skool" metal piano hinge jars with the clean minimalist lines of this chair. I love the poster who suggested leather! Maybe consider plastic "living hinges" (google it) these are one-piece and very inexpensive/clean looking. Try or

    Second, the chair lends itself to thin material, but then you have too little "bury" for screw fasteners. Maybe consider pop rivets? You'd want something attractive from both front and back (countersunk? Stainless?) but these are available. Check out home-built aircraft suppliers (eg: Aircraft Spruce)

    It'd be too cool if you could just use some kind of tape instead of hinges, like gaffer's tape, and be done with it. Adhesion can be much improved if you pre-coat the wood with contact cement where the tape is to go, but I'm afraid even the toughest tapes (Kevlar; Dyneema) might have a limited life. Have you considered maybe building the chair of Coroplast corrugated plastic and heavy duty tape? There are some very good looking examples of this online.

    2 replies

    Even strips of polypropylene attached with staples would do fine for a quick and dirty version. Polypro has tremendous durability as a hinge. You could use coroplast or even some kind of food containers for the hinge source.

    It actually could fold with some minor tweaks. Really impressive design. Thanks for sharing!

    Fascinating design, like several others, I thought it folded till I looked closer. I'd love for you to take it in that direction for V2.0

    So this chair does not fold? And if it does not fold why use hinges to attach all of the pieces? If all the hinges do is hold it together, would it not be a lot cheaper to just use a strip of metal bent to the proper angle? Once it was assembled, would it not be just as strong?

    3 replies

    I'd use a heavy riveted leather instead of the hinges, It would be far less likely to rip out peoples hair than a piano hinge.

    The hinged connections allow me to assemble the faces expediently AND precisely. If I had a sheet metal break it might make more sense to do what you're saying but this approach has also proven to be somewhat tedious with complex polyhedra since it requires many more connections to be made "up in the air." It's easy, with a little imprecision, to get error creap. Also, breaking all the different angles on a complex job would detract from the efficiency of the making. At least with my tools. I'm interested in the properties of folded plate structures and making connections "semi rigid" detracts from the rigor of this inquiry (I.e. he objects are rigid because they are braced by other planes, not because the joints are fixed.).

    A few other advantages of using hinges to fasten a folded plate project: you don't have to figure out the seam angles, you don't have to break steel straps precisely, and you can let the plates flop around while you're adding the hinges to the other seams. This is especially useful in a project like this when you've got "mountain" and "valley" folds at the same time. $5 for a piano hinge vs. $2 for a perforated steel strap doesn't make a significant dent in the budget unless you're making 1,000 copies of the chair to sell.

    Despite all that, I like the hinges conceptually. You're calling this a "folded plate" project, which basically means origami. Origami folds, and so do hinges. The material and the construction method both support the concept.

    i really like the design. what software you used in order to design the chair and its assembly ?

    1 reply

    You might look around but I can get hinge like that without holes drilled in it. Will add some time but you can drill and counter sink the holes (on the "correct" side). Here at least its cheaper than the drilled.

    Love the idea and plan on adding it to the umpteen million other projects I need to get done.

    1 reply

    You should be able to drill into the plywood with a 3/8" screw without any problems. Just posted a video that should show the attachment process relatively clearly.

    I really love this type of projects. Once Popular Mechanics and Science were filled with such projects, now a days they have high funda workshops and forgot to work by hands!! I request you to include small wooden functional articles to make in such instructables!! thanks a lot , this reminds me PS/APA contests from popular science!!