The chairs had four legs, each of which radiated out horizontally from a central point (they were swivel chairs) then turned downward to the floor. The legs were about 1/2” wide, maybe a bit more. They were maybe 1” tall (vertically in the horizontal section and horizontally in the vertical section).
So the grain needed to run horizontally in the horizontal part to support the bending load. It was probably best for the grain to be vertical in the vertical part, although that was maybe less critical: that section was mostly in compression. It probably also looked better that way.
In any case, the actual construction put a finger joint in the horizontal section just past the turn, so a tiny bit of vertical grain wood extended horizontally over the turn. And several of the legs cracked just along the side of the finger joint, and one failed completely after about a month of gentle use.
The design plausibly could have worked if the joint went diagonally through the turn or was below it. But plywood is strong along both in-plane axes, and the legs could likely have been cut in single pieces from sheets of plywood with strength to spare.
Attractive plywood, even from hardwood species, is readily available. The plies are visible along the cut edge, but this is actually a style people like, especially in Scandinavian furniture. Even IKEA sells some nice chairs with plywood elements, at entirely reasonably price points.
So the grain needed to run horizontally in the horizontal part to support the bending load. It was probably best for the grain to be vertical in the vertical part, although that was maybe less critical: that section was mostly in compression. It probably also looked better that way.
In any case, the actual construction put a finger joint in the horizontal section just past the turn, so a tiny bit of vertical grain wood extended horizontally over the turn. And several of the legs cracked just along the side of the finger joint, and one failed completely after about a month of gentle use.
The design plausibly could have worked if the joint went diagonally through the turn or was below it. But plywood is strong along both in-plane axes, and the legs could likely have been cut in single pieces from sheets of plywood with strength to spare.
Attractive plywood, even from hardwood species, is readily available. The plies are visible along the cut edge, but this is actually a style people like, especially in Scandinavian furniture. Even IKEA sells some nice chairs with plywood elements, at entirely reasonably price points.