One would be in an unsettled mood when you sit inside the semicircle, which one rarely sit on. On the other hand, by making the seat surface a semicircle, the armrests are integrated directly into it the structure, and it defuses one’s tension as if being wrapped. Sitting in this chair gives the user such a complex feeling of tension and defused friction.It may resemble a chair for sitting alone in the dark.
I wanted to make the plate thickness as thin as possible in order to give the feeling that the seating surface of the semicircle is floating in the air.
The thickness of the aluminum plate used is 4 mm thick for the seat surface, 6 mm thick for the side plate, and 10 mm thick for the two members that cross each other while supporting the seat.
Initially, the thickness of the side plate was 4 mm, but it was found that welding of 4 mm and 10 mm thick members causes distortion of the side plate. As a result of investigating a method of fastening the two side plates and the member connecting them without welding, the thickness of the side plates was made 6 mm thick, and by incorporating a special spring pin in the 10 mm thick member, I succeeded in fastening them without welding.
This design is an extension of the second aluminum chair design "Shades of Brunelleschi", but it is a chair that is simpler than the second one and is closer to a stool.