July 28 Laser cutting a living hinge
Living hinges allow for usually rigid materials such at timber and plastic to bend and flex and can incorporate an interesting aesthetic and as solve design problems. We’ll show you the basics and how to achieve this with laser cutting.
There are a number of open source CAD designs for living hinges available to download, this is a good place to start especially when in the prototyping phase, then you can tweak the designs as you wish.
We started by testing the great range of designs by the folks over at Instructables, (download their living hinge designs here), to see which design would work well for our project: a self-standing flyer holder. We are working at a reasonably small scale, our flyers are A6 size, so the hinge needed to work on a small scale. We needed to utilise a living hinge to enable the ‘lid’ of the flyer holder.
Once we cut the Instructables designs from our chosen material (3mm plywood) it was clear that some of the designs did not offer the flexibility required at that scale, so quickly we narrowed it down to two options. We settled on Instructables ‘Parametric Kerf #3’ (header image). The simplicity of the design and repeating curved shapes offered us a great deal of flexibility without forfeiting too much structural integrity.
Some of the simpler living hinges can make the piece very fragile, and depending on the end use, may not be suitable. Since our flyer holder is going to be moved around and touched by lots of people, we went with quite a tight design that was not easily breakable.
We made a few subtle tweaks to the spacing, (namely elongated the shapes slightly and tightened up the spacing in between) then we designed the ret of our holder to be assembled with finger jointed edges.
A note on grain. Initial testing leads us to believe that the hinge should run along the grain, not across it. This adds more flexibility to the timber, as rather than working against the grain, you are harnessing it’s structural composition.
Adding a living hinge element to your project can add interest and more importantly, more possibilities with the materials you use. We highly recommend running a range of tests and prototyping your design first to make sure you achieve the desired result. Get started on your next project by downloading our laser cutting template.
For further information on general laser cutting, please check out our FAQs for some guidelines.