Cardboard Chair Design
Once we build our passive solar house, we realized that it's rather pointless to have a building without any furniture. We were assigned the task of making economically reasonable chairs out of cardboard. Our few restrictions were: the cardboard had to be single-ply, we were to use no fasteners or glue (only cardboard), we were to use a maximum of 64 square feet of cardboard, and that the thickness of a single sheet of cardboard may not exceed 1/4".
Key Concepts:
tensile strength: the resistance of a material to breaking due to stretching (tension)
compressive strength: the resistance of a material to breaking under compression
center of gravity: the place in a system or body where the weight is evenly dispersed and all sides are in balance
tensile strength: the resistance of a material to breaking due to stretching (tension)
compressive strength: the resistance of a material to breaking under compression
center of gravity: the place in a system or body where the weight is evenly dispersed and all sides are in balance
Our Design:
Out of all aspects of our cardboard chair design, we definitely focused on structure and function first and foremost. Our chair ended up being exceptionally sturdy, as a variety of 170+ pound boys volunteered to stand upright on our chair, and it held right up! So, to make our chair so sturdy, we added a lot of vertical inserts into the core (base) of the chair, where you sit. All of these supports had grain going vertically, as when it is running vertically the cardboard can undergo a whole lot more compression than if it were running horizontally; in fact, the cardboard is extremely liable to bend and crease if the grain is running horizontally, and since cardboard is rather inelastic, once it bends it is rendered practically unusable. No amount of reinforcing will likely be enough to return the cardboard back to its original strength, not that it would be very worthwhile anyway; you use exponentially less cardboard by simply running a brand new piece into the design than using sheet after sheet to reinforce your already broken sheet.
We essentially totally neglected aesthetics of the piece, partly because we were extremely crunched for time and partly because we decided that having a working, sturdy chair was more important than having a pretty one. We rounded out the back of the chair to deter from the previously square, jagged back, and actively seeked unmarked and uncreased bits of cardboard to try and clean up the general look of the chair.
Regarding economics of the chair, since we used triangular structures inside the body of the chair, it took away the need for using endless sheets of cardboard stacked on top of one another to offer the same support that the simple supports we crafted did. And, by utilizing the vertical flow of the grain, we offered more support using less cardboard.
Out of all aspects of our cardboard chair design, we definitely focused on structure and function first and foremost. Our chair ended up being exceptionally sturdy, as a variety of 170+ pound boys volunteered to stand upright on our chair, and it held right up! So, to make our chair so sturdy, we added a lot of vertical inserts into the core (base) of the chair, where you sit. All of these supports had grain going vertically, as when it is running vertically the cardboard can undergo a whole lot more compression than if it were running horizontally; in fact, the cardboard is extremely liable to bend and crease if the grain is running horizontally, and since cardboard is rather inelastic, once it bends it is rendered practically unusable. No amount of reinforcing will likely be enough to return the cardboard back to its original strength, not that it would be very worthwhile anyway; you use exponentially less cardboard by simply running a brand new piece into the design than using sheet after sheet to reinforce your already broken sheet.
We essentially totally neglected aesthetics of the piece, partly because we were extremely crunched for time and partly because we decided that having a working, sturdy chair was more important than having a pretty one. We rounded out the back of the chair to deter from the previously square, jagged back, and actively seeked unmarked and uncreased bits of cardboard to try and clean up the general look of the chair.
Regarding economics of the chair, since we used triangular structures inside the body of the chair, it took away the need for using endless sheets of cardboard stacked on top of one another to offer the same support that the simple supports we crafted did. And, by utilizing the vertical flow of the grain, we offered more support using less cardboard.
All in all, this project was mildly successful. It did teach me the value of making careful, research based and evidence supported decisions to make final choices, and taught me to work efficiently under pressure and a tight deadline. This project might have been more successful for our group had we decided to focus more of our attention and effort into this project and less towardw