Using your understanding of structural forces, design a chair or stool using only one sheet of 2′ x 4′ thin gauge aluminum sheet. The structural forces include; compression, tension, shear, torsion and moment principle.
My initial thoughts about making a chair were, “I hope we make the chair out of wood.” Now that I realize the material we’re using to create the chair is aluminum, I feel like it will be more difficult for me because I don’t have experience working with aluminum. Working with that one sheet of aluminum will be challenging because we have to plan out exactly how much we will need for each component of the chair. After thinking about ideas for my chair, I want to do a simple but efficient design.
- I really like how simple this wooden chair is, since it’s made out of wood it has the shear force to hold a heavy weight.
- I like the clean aesthetic of this rocking chair, it’s efficient and contains repetition by
the multiple pieces of wood on the backing.
- I like this metal chair because it’s dynamic by the two colors and the repetition of the wood pieces on the backing and seat.
- I like this aluminum chair because the beams connecting the legs of the chair provide a triangular support that makes the shear strength of the chair stronger.
- As for chairs made for comfort, I have always liked these wooden circular chairs with the huge cushions.
Chair History Timeline
The history of the chair dates back to ancient Egypt. The chairs were typically fancy thrones that were made of ebony, ivory and carved wood.
Greek chairs date back to six or seven centuries BCE. Roman chairs were made of marble.
Medieval chairs have religious significance and were created in the 16th century.
China typically had sitting mats instead of chairs. It wasn’t until the 12th century that chairs became popular.
During the Renaissance, chairs were a status symbol.
The majority of the chairs until the 17th century were made of timber (oak) with upholstery, they were known for their massiveness and solidity.
The 18th century was the golden age of the chair, especially in France and England. During this time, the rocking chair was invented in North America.
The Art Nouveau schools produced simplistic chair designs during the 19th century.
During the 20th century, the increasing use of technology in chair construction leads to metal folding chairs, recliner chairs, beanbag chairs, etc.
For the material study we learned how to use the shear cutter, bandsaw, the hydraulic press, the machine that stretches and shrinks metal, the machine that folds metal and the drill press. By creating this material study I learned a lot of new skills, such as using new tools and experimenting with aluminum.
Process for Figures 1 & 2
- I first marked a two inch line on my piece of aluminum.
- Then I used the shear cutter to cut the two inches off the aluminum.
- I marked a hole location on one of the pieces of aluminum.
- I used a clamp to keep the two piece of aluminum together.
- I drilled a hole.
- I installed a cleco.
- Then I removed the cleco.
- I deburred both sides of every hole.
- Then I installed a rivet with the head on the outside.
- Placed the rivet gun squarely on the head.
- By holding the bucking bar firmly on the backside of the rivet and pulling the trigger slowly, I was able to create that smooth, flat side of the rivet.
Process for Figure 3
- I measured a half inch line on my piece of aluminum.
- I used the metal folding machine to fold the aluminum on that line.
- Then I used machine that stretches and shrinks the aluminum. I shrinked the aluminum, by clamping down on half inch segments to create a curve.
Well, lets just say that this is the second maquette I made when the first one I created ended up in the trash. I ended up building up sketch #6 and writing down all the measurements. Once I had created the maquette, I realized that I found the chair “too boring” and nothing seemed to work to make it more dynamic. So I created another sketch, it sort of ended up looking like a “bar chair” with the shorter back and the tall legs. I liked how the strips in the backing create repetition and pattern. I based my final maquette on the bar chair design. Making the maquette out of paper is a lot easier than making it out of aluminum.
Process: Well…this chair process has definitely been an adventure. It has includes much frustration, learning new techniques and working with new materials that I don’t have experience with. To being with, I cut my aluminum sheet wrong because I realized that the shear cutter doesn’t cut 40″ long pieces. Eventually, I creative problem solved and split the back leg lengths so I could cut them on the shear. Once I had all the aluminum pieces cut, I began the assembly process of folding, drilling, demurring and riveting. I found this part to be the most fun.
Everything was going smoothly until I realized that I must have assembled one chair leg a half inch too long because the whole chair was uneven and wobbly. So after a couple minutes of panic, my professor helped me align my chair by taking out a couple rivets and re-drilling holes for new rivet locations. During this part of the process I was frustrated because I felt like I was “re-doing” my whole chair. However, this part of the process was essential because now my chair is aligned correctly.
After I put together my chair I used a small metal cutter to cut a half inch off three of the chair legs and FINALLY my chair does not wobble! The last part of the process is the polishing with the drill. I found this part to be the most satisfying. Even though, all the sharpie marks and scrapes represent all the hard work, it felt great to polish and clean the whole chair.
Finished Piece: Despite that the process felt time consuming and repetitive
at times, I am very happy with how my chair came out. I like the “tall” aspect of my chair because it’s meant to resemble a bar chair. The four strips on the backing and the equal number of rivets represent repetition and pattern. The bars that connect the chair legs create a triangular structure that adds to the shear strength.
If I were to do this project differently I would plan it out more efficiently. I think that I was so caught up with having this big project to make a chair, that I didn’t think of all the technical details. Such as the length of the shear cutter and making sure my chair legs were at 90 degree angles. Originally I was all for making a shorter chair design, but I am glad that I created the taller chair design. My chair is basic but efficient, my professor already sat on it and it held!
I learned a lot of valuable skills during this process, I learned how to use the shear cutter, bandsaw, drill press, hydraulic press, air drill, rivet gun, cleco installation and rivet installation. One of the most valuable things I’ve gained from this process is patience. If one thing doesn’t work, that doesn’t mean that the whole chair is ruined, problem solve until you come up with a solution.