Wooden springs seem unlikely, but laser cutting makes them possible and avoiding plastic in toys and models makes them desirable. There are many reasons that plastic has been so successful, some of which are also a problem, such as it’s indestructibility. Pliable and easily moulded to almost any shape plastics have become the central product of our times – found literally everywhere. For a designer the challenge of avoiding plastic is compelling but hard, a little like giving up junk food.
Plywood is a wonderfully versatile of material and completely sustainable in managed forests, has been around for thousands of years and is widely used in our homes and industries. But like all other materials it has some limitations and these become clear when designing on a small scale and for a range of movement. As every parent knows young children can be hard on toys, plastic parts stand up well to rough treatment but can wood or plywood do as well? Many wooden toys rely on small amounts of metal or plastic – for axles, end caps, springs and so on, this is something I want to avoid.
Trying to make wood behave in a springy way is not new and there are plenty of successful examples, the IKEA Poang chair is one. And of course wooden ships had to flex and move with the forces of wind and wave.
The advent of laser cutters allowed for the invention of the ‘living hinge’ but these items are yet to become commonplace in our homes. I am trying out living hinge springs, that is using these things edge-on and within guides so that they cannot bend, only compress or expand on one plane. A question arises as to how robust such a spring might be, but I only want a tiny amount of movement – 2 or 3 mm – and this should not be too hard on the material. This type of spring is fairly common in plastic disposable items and isn’t something most of us notice.
Why is springiness useful in a self-assembly toy? Well, anywhere there has to be movement that movement has to be controllable, to stop and start when required and not to move unless required. Friction is the most common controller, on axels and wheels for instance. And many plywood models use rubber bands. But the possibility of an all-wood mechanism appeals to me, so I will keep trying and I expect to have new models with these things working on sale soon.