4. Designs,Prototypes, & Testing

[Aims]

 

The height of a chair should be optimized for the current table in order to use a kitchen conveniently and comfortably.

 

Various cultural habits must be considered.

 

All functions must be easily accessed.

A First Idea Sketch

When designing the first prototype, I had to consider the height of a chair that would be used for working in a kitchen, so it had to be taller than a dining chair. If this had not been the case, someone using it would tire too easily.

 

Additionally, in order to make it possible for someone to sit cross-legged on the chair, it needed to have extra space for the their legs. There were two options; one was providing a wider seat, and the other was adding a platform for folded legs to rest on.

 

The sketch shows a portable wider chair with two wheels, which could also be used as a shopping cart for an elderly person. A cover attached to the chair works as a 'flexible table' for their kitchen work. However, I had some doubts about the usefulness of the cover and the portable function.

 

A Prototype 1.0

 This was the second option, which provided the user with support for their legs. Test results proved that this option was more comfortable.

A Prototype 2.0

In designing this prototype, the cover and wheels were removed due to doubting their necessity in real life. The hanging support for the user's legs could be folded, and it may be useful in a small kitchen. However, there was some instability and the small size of the platform could cause someone to fall.

A Prototype 3.0

 Prototype 3.0 provided a fixed platform and a backrest, but while testing this prototype, I found that the fixed platform could make it difficult for the user to sit down or get off the seat.

A Prototype 3.1

The platform on the Prototype 3.1 could be folded with a rod supported on the platform. The front legs and the rear ones are fastened by two flexible plastic straps in order to not collapse.

The issue with the prototype was that the rod was so long that the chair couldn't be folded completely.

 

Given the very busy situation in the kitchen, the idea regarding the backrest should be removed or fabricated later since I guessed that users would not have time to lean on that while busily working in their kitchen.

A Prototype 3.2

The rod for the platform was designed to be shorter to be more folded.

 

One of the findings from interviewees who tested this chair was "it is wonky."

 The idea sketch was approached to make the chair structurally stable, so the angle of legs should be wider and rigid material was considered instead of the plastic straps.

 

What concerned me about the chair was higher labor costs for its complexity. Given the low-income population, the chair must be more simple. In addition, the upward folding platform would still give users difficulty when they get off.

An Idea Sketch for a prototype 4.0

A Prototype 4.0

The prototype 4.0 was designed to be stable. In addition, users could sit on and get off the seat more conveniently.

A rod was attached under the platform to be unfolded downward as the user kicked it when they tried to get off.  A rubber band connected from the rod to the horizontal bar between the rear legs made the platform keep turning up and flip it down easier.

A Prototype 4.0 Test

 All testers were satisfied with the chair because of the supportive and comfortable cross legged sitting pose. However, they sometimes wanted to sit on there differently. In addition, many testers appealed to fabricate a backrest.

A Prototype 4.1

A swivel was installed on the top to sit easier. A way to 'sit and then turn' without the swivel also could work on the prototype.

However, given the need for a backrest and arms that users grab to sit on the chair securely, installing the swivel was necessary to sit smoothly.

A Prototype 5.0

Prototype 5.0 was designed considering aesthetic aspects and production costs.

Plywood cut by a CNC (computer numerical control) router machine was used as the main material.

Since the prototype followed prototype 4.1, it worked in the same way.

While I was observing testers' trials, the way to get off the 'kicking-bar' seemed that the rod could become weakened, and it swung back and forth as well as left and right.

In addition, some users hoped that the size of  the platform expanded due to their legs size.

A Prototype 5.1

A Prototype 5.1 Test

For prototype 5.1, two rods were used in order to fix the swinging rod issue but the two rods  were rather twisted when a user kicked the bar.

Additionally, I noticed that the bar could hook users' heels and trip them, and leaving the chair seemed to be awkward for users.

A Prototype 5.2 platform folding system

The platform size was more wide to reflect the opinions the testers gave.

I made a rail on the rod to move it in the right direction, and the 'kicked bar' was removed due to safety (hooking foot possibility) and a structural reason from the rail. I had to figure out another way to flip the platform down to get it off. Even though the principle of the fold platform system was complex, I needed to build and test it to explore, understand, and find clues.

A Prototype 5.2 Test

A Prototype 5.3

The complex fold system was simplified by designing a circular hinge having a track and lever that can control flipping.

When users tried to sit on the chair, they flipped up the platform. They could pull the lever up when they wanted to flip the platform down to leave the chair.

A Prototype 5.3 platform folding system

A Prototype 5.4

The hinge was reinforced by assembling it with a metal sheet and its edge was rounded for the users' safety.

A Prototype 5.4 Test

Testers could sit on the chair and leave that easily, and the feedback was very positive due to its convenient control and supporting the comfortable sitting pose.

A Prototype 5.5

This is an extra prototype for a high-end version. Many young testers gave very positive feedback for the X-chair's supporting comfortable cross legged sitting pose, so I considered there could be a potential customer population, giving the chair a different operation system so that it could have an appearance in a unique expression.

A Prototype 5.5 Test

Prototype 6.0

Prototype 6.0 was designed for the basis of mass production.  Plastic and steel were used as the main materials, and I designed it as simple as possible in order to make it inexpensive for low-income seniors.  The lever of the flipping platform grew longer to reach the user's hand.

The lever of the flipping platform grew longer to reach the user' hand. Just pull up the T-shaped lever, and the platform will flip down.

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