A Pop-up Chair

MISSION STATEMENT

The Chair Project is the term project for the last of the sequence of four required Structures courses in the curriculum of the University of Waterloo School of Architecture.

The project requires the design, construction and structural analysis of a folding or take-apart wooden chair for a client of student’s choice.

PROBLEM SPACE

Identifying our clients

Due to our background of Asian culture, we set our view on the limited per-capita residential space in Asia. Especially in metropolises like Tokyo, the extremely high population density results in more than one generations living together in an apartment. Therefore people always prefer room-saving and functional furniture. Here are two space-saving examples

Project goal

Design a chair that can save living space and improves the quality of life for a family.

DESIGN

Our creation process subdivides itself into three tiers: prototype, evaluation, and construction.

During our prototype stage, we had a brainstorm to find a notion method to meet the user's requirement. Eventually, we got inspired by the popup book master, Waldo Hunt, and determined the concept of “Popup Chair”.

Then in the evaluation stage, users’ feedbacks and structural analysis contributed to the crucial improvement in the design of the chair. The rigorous first two stages ensured the success of construction.

PROTOTYPE

Low fidelity prototype

We started with extensive exploration to gather possibilities. The key method is creating a minimal version first and then optimize it according to test and feedbacks again and again.

Reference: Cut and Fold Techniques for Pop-Up Designs by Paul Jackson

We have introduced techniques for making pop-ups from one sheet of card.

High fidelity prototype

The feasibility of constructing the chair is rather crucial in this stage. We built different models for various tests, and calculate the physical property of the chair in the worst case to guarantee the safety of users.

1:1 model

We first made a 1:1 model with foam board to review the design, which helped us to realize some problems on the ratio and dimension. Then we built another rough 1:1 model with wood and this time we apply piano hinges in joints. It’s of great importance when gathering authentic feedbacks.

 

 

EVALUATION

Structural analysis

The weight of the chair, the center of gravity, overturning forces

Reactions, tipping forces

Load take-down/frame analysis

Lateral stability and racking

Beam analyses: actual shear and bending stresses, and best approximation of

Deflection

Users’feedback

In the final review for chair design, we invited the reviewers to try our 1:1 rough wooden model, and received plenty of valuable suggestions:

Make the holder bigger to allow the forearm to get through.

Lower the chair 5cm to achieve better ergonomic performance.

Cut some area off to reduce the weight and to be more portable.

Strengthen the side chair with extra support for psychologically stable though it’s strong enough for a 70kg person