Planning
Purpose
We are making a chair in order to learn 2D CAD and iterative design. We are also making this to learn how cardboard can be strong with the right joints.
Criteria
We need a chair that is strong which we can sit on it without it breaking. It would be nice if it looks like a regular chair and it doesn’t hurt when we sit on it.
Constraints
We have 3 sheets of 50x100 cm cardboard and 5 days to design and build.
Proof of Concept
We thought of making a cube but were concerned it uses too much material so we decided to make a stool using intersecting pieces of cardboard to make a grid. We tried implementing with a small scale but it was too weak and the feet collapsed, therefore we will use shorter feet for our next version.
1:5 Scale Model
Our second version was cut by the laser machine and it was quite strong although the feet were not strong so we will not have feet at all for our final version. We also found out that 3 mm for joints is very tight so we will increase the gap next version. The method of assembly was also challenging as we had to bend a piece in order to put it together which impacted the structural integrity.
Final Version
Using what we learnt we designed a very simple chair that was easy to assemble. The design was quite strong but was not comfortable and the top cover could have been mounted better. When a lot of force applied, it collapsed on it's self, we realized that the joints were the parts that would bend the most so if we could change it we would have used smaller joints.
Reflection
Overall our final design was pretty good although our original design had some flaws, throughout 2 prototypes we were able to eliminate most of the problems including weak legs and difficult assembly method. In the end we were able to create a strong chair that could support us but did not meet our requirements of being comfortable and looking good.