The Flat Mate
TEAM
TIMELINE
SKILLS
Me and 3 other students
12 weeks
Prototyping, CAD, Manufacturing Processes, Structural Analysis
2022 / PRODUCT DESIGN
The brief challenged us to design a folding chair for students and individuals in shared living spaces. Recognising the need for a space-saving and versatile furniture piece, we aimed to create a product that could compete with popular, low-cost options from op-shops and Kmart, while also offering better practicality and ergonomics.
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The result is the Flatmate—a compact, versatile, and affordable folding chair. Designed with an easy-to-use clutch-lock adjustment mechanism, it can transition from full-size to a shorter height, making it ideal for various settings like shorter tables, watching sports, or the beach. The chair is stackable for convenient storage, and features a rubber stopper and feet to protect walls and floors. With identical, ergonomically designed seat and back panels made from injection molding, and a lightweight yet durable aluminum frame, the Flatmate combines cost-effective manufacturing with adaptability for dynamic living spaces.
The Problem and Brief
DISCOVER
The brief was to design a folding chair for a chosen user group. Our team selected students and individuals in shared living spaces, recognising that a space-saving and versatile piece of furniture would be ideal for this environment. Competing products, such as those from op-shops and Kmart, are popular for their low cost and accessibility. Therefore, our goal was to focus on economical manufacturing methods and materials while ensuring the chair offered a high level of practicality and ergonomics.
Based on these considerations, we refined our brief to:
How might we design an economical and space-saving chair for shared living environments that doesn’t compromise on ergonomics?
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Technical Research
DISCOVER
To begin the design process, we started by analysing and deconstructing an existing folding chair design to understand its required parts, manufacturing methods, and mechanism of function. We chose to analyse the Kinno chair by IKEA, introduced in 1978, due to its simple and intuitive folding/unfolding action and its slim, thin profile when folded. This chair was produced using cost-effective methods, but it was notably uncomfortable to sit on.
We measured the geometry of the linkage system, including the angles and distances between connection points, and then recreated a 2D depiction of the chair in Fusion 360. The model was laser cut from MDF and assembled using washers and bolts to create a one-third scale validation model of the chair.
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Ideation
DEVELOP
Each group member ideated two viable chair designs so we could select and combine our favourite concepts and features. My designs focused on adapting and iterating the Kinno chair to improve ergonomics and exploring alternative cost-effective manufacturing methods.
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My first concept was designed to come partially assembled, reducing assembly costs and saving space during distribution. This design also allows for an adaptable chair with adjustable height, making it convertible into a versatile smaller chair suitable for the beach, easy storage, lower tables, or as a lap table for a laptop. This also allows for the canvas seats and backrest to be removed and washed if desired, ideal for messy flat environments. ​​​
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My second concept explored the use of blow moulding as a cost-effective manufacturing technique. The two seat panels and the backrest are identical, reducing mould costs by requiring only one mould. Aluminium poles are bent to fit into holes machined after the part comes out of the mould, eliminating the need for additional fasteners. The seat and backrest panels are designed to curve around the tubes, providing extra support and a comfortable shape.
Concept Development
DEVELOP
The group evaluated all eight concepts; the two I submitted emerged as favourites, particularly for the variable height feature of the first concept and the identical seat and backrest panels of the second concept. We created quick sketches to combine these features into a new iteration, followed by a CAD model to realise the concept. The new design incorporated button clips (similar to crutch adjustment mechanisms) for leg adjustment and featured identical injection-moulded seat panels.
Prototyping and Testing
DEVELOP
Height Adjustment Mechanism
We created a rough 1/3 scale model of the chair to test the usability of the adjustment mechanism. During testing, we found holding the buttons on each leg challenging while simultaneously adjusting the chair's height. As a result, we decided to redesign the mechanism to be simpler to use.
Ergonomics
We carved foam panels to match the curvature of the CAD-designed seat and backrest, then strapped them to a rig that allowed for adjustment of the seat and backrest angles. Testing revealed that the initial panel design was too flat, and the backrest was angled too far back. We created a new panel with more curvature and adjusted the rig to achieve a 102-degree angle between the backrest and seat. These changes significantly improved the chair's ergonomics and comfort.
102 degrees
The second ergonomic test involved assessing the seat angle in the lower position. We placed planks of wood underneath the rig to mimic the effect of a longer front leg, shifting the user's centre of mass backward to prevent the chair from tipping forward. A 40mm increase (using two planks) was too steep, but a 20mm increase (one plank) provided a comfortable and appropriate difference between the front and back leg lengths.
Concept Refinement
DEVELOP
To refine the design, each group member created another iteration, making adaptations based on the ergonomic tests and development points. My iteration included three main changes that were implemented into the final design:​
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Stackability: Allowing the chairs to be easily stacked for efficient storage.
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Rivets and Fasteners: Added for increased durability.
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Fifth "Foot": Added to the back of the seat to protect walls from scratches during storage. This foot was made from the same mold as the other feet to save on manufacturing and mold costs.
Another teammate created an iteration that utilised a more user-friendly bike lock mechanism to replace the button clip. While we appreciated the functionality, we found the aesthetic too bulky. To address this, we researched alternative mechanisms and decided on a clutch lock mechanism. This design works by unscrewing the cylindrical connector, pulling the poles apart, and then retightening the connector. It provided the usability of the bike lock but with a sleek, seamless aesthetic.
Final Design
DELIVER
The Flatmate is a compact, versatile, and affordable folding chair designed for dynamic, shared-space environments. It features an easy-to-use clutch-lock adjustment mechanism on the legs, allowing the chair to be adjusted from full size to a shorter height with an infinitely incremental range in between. This design makes it easy to store in its shorter position and versatile enough for various uses, such as for shorter tables, watching sports, at the beach, or as a lap table.
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The chair is stackable for convenient storage and includes a rubber stopper on the back to prevent marking walls in rental spaces when leaned against a wall. Rubber feet on the bottom protect against floor scratches and provide grip. To minimise manufacturing costs, these components are made from the same mould. The injection-moulded seat and back panels are also identical and ergonomically designed for comfort. The rest of the chair is made from extruded aluminium tubing, offering a lightweight yet durable final product.
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Overall, the Flatmate utilises cost-effective manufacturing methods to deliver a quality chair that is compact yet adaptable to various needs and environments.
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The following posters were made by my other team members to showcase the design:
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Structural Analysis
DELIVER
As the final part of the design process, a structural analysis was conducted to verify that the design was durable enough and met the AUS/NZ standards. I completed the calculations and poster layout on behalf of my team:
