What if you design a seating object that can take different forms? A seating object that is as multi-functional as possible. That was the starting point for this particular product. Broadly speaking, three seating heights can be defined: that of a lounge chair, that of a dining chair and that of a bar stool. For Stilst designer Reinier de Jong, the challenge in 2007 was to combine all three into one piece of seating. It was a different time when (more than now) conceptual design prevailed. Below he tells his story about the development of this particular piece of furniture.

Designing

After much sketching and modeling, I manage to combine not only the seat heights but also the corresponding backrests and the varying angles between seat and backrest. To achieve an attractive, consistent shape, the protruding parts have the same thickness and the same radius at the end. The width of each module of the seating object is 20 cm allowing you to make chairs 40 cm, 60 cm wide or even benches.

Prototyping

I made the first prototype by cutting the outline of the side from a sheet of mdf. I connected the two outer sides with straight plates. I made the curved parts by bending and laminating layers of wood veneer in a curved mold. I had the second, solid prototype milled from a sheet of polystyrene foam. This gives you the right shape immediately. A fiberglass-reinforced PU coating was applied around this. Of these, I had some copies made to test the connection method between the modules.

Modular connection

To connect the 20 cm wide modules, I tested some push-button connections but they proved to be inadequate. Testing magnets was the next step. The standard ferrite magnets did not suffice either, but very strong neodymium magnets fortunately did. By default, however, these are all magnetized in the same way which would cause them to repel each other. With a supplier from Germany, it turned out to be possible to provide half of the magnets with the opposite pole.

Production

The next step was to put the chair into production. For this, the polystyrene version proved unsuitable, partly because of too high a cost. I ended up at a Dutch company that specializes in making marine fenders by rotation-molding. Rotation-molding involves putting a plastic granule into a mold, which is then rotated around its axis in an oven over and over again. The granules melt against the walls of the mold. After a cooling-off period, the object can then be released from the mold. The mold used for my seat object was cnc milled from a single block of solid aluminum. To fasten the magnets with bolts into the chair, some brass inserts were cast into the mold with them. The chair was in production for several years and could be ordered in a variety of colors.