Half-Scale Cardboard Chairs

Problem finding is one of the hardest things to teach any designer -- it involves ranking all of the problems you can think of with a design challenge, and saying which are the hardest and make the most different in a design. Making the back of the cardboard chair strong enough to resist the forces users will apply when they lean back when seated is a major challenge of this task. This becomes easier to test as students make their half-scale chairs.

In MOVIE 1, Ed helps students structure their remaining time on the project by showing them a calendar of events. Students must select two ideas to pursue, and then fill out Idea Evaluations on each. They revisit their original chair specifications and, if needed, revise the criteria and constraints they will follow as they finish their work. Ed introduced corrugated cardboard as their building material and orthotropic lines, which states that cardboard is stronger against bending in one orientation than another where the material has been rotated 90°.

In MOVIE 2, Ed reviews the impact on chair strength on bending and compressive strength of moving from quarter- to half- to full-scale, and concerns for limits of materials. Listen to students' explanations for their chair designs, and the metaphors Ed uses to get them to focus on particular areas of weakness in the chairs students make.