How to make a living hinge box
- Measure your sheet thickness with callipers and your laser's kerf with a test cut, and enter both.
- Enter the inside width, depth and wall height, and the corner radius (about 30 mm suits 3 mm plywood).
- Check the flat layout, then download the SVG or DXF and confirm the size in your laser software.
- Cut one hinge corner on scrap first and bend it by hand. If it feels stiff, reduce the slit spacing.
- Cut the box. Bend the strip round the base with the tabs in their slots, add the top ring, and glue if you like.
How the living hinge works
Each corner gets rows of short slits across the wall, with every other row shifted by half a slit. The thin wood between rows twists a little instead of bending, so a stiff sheet curves smoothly. The hinge covers the whole corner arc plus a little straight wall on each side, and the strip is laid out along the middle of the wall, which keeps its length when it bends – so the tabs land exactly on their slots.
Frequently asked questions
What is a living hinge box?
A box whose wall is one strip of plywood or MDF. Rows of short staggered slits at each corner let the strip bend round a rounded corner, so the box has smooth curved corners instead of finger joints. Tabs on the strip lock it into slots in a base plate and a top ring.
Which materials bend?
3 mm plywood (birch or poplar) and 3 mm MDF bend well; 2–4 mm works. Acrylic only takes a gentle, fixed curve and cracks if it is flexed – use wood for this box.
How tight can the corners be?
With straight staggered slits, 3 mm plywood bends comfortably to a corner radius of about 30 mm (about 10 × the thickness). Tighter corners need closer slits and longer slits, and may crack – the tool warns you when the radius is tight. Cut one corner as a test first.
Are the dimensions inside or outside?
Width, depth and height are inside sizes. The wall adds one thickness all round; the base, ring and lid stick out a few millimetres more so the slots have material outside them. The outside size is shown under the preview.
What does kerf compensation do here?
Outlines grow and slots shrink by half the kerf, so tabs fit their slots snugly. The hinge slits are single cut lines – their width is simply your laser kerf.
How do I put it together?
Bend the strip gently round the base, pushing each tab into its slot (start at the back, where the strip ends meet). Put the top ring on the upper tabs. A drop of wood glue in the slots makes it permanent. For the lid, glue the insert under the lid, centred – it drops into the ring and keeps the lid in place.
My strip is longer than my laser bed – what happens?
Set your sheet width. If the strip does not fit, the tool cuts it in two at the middle of the front wall, so both joints sit on straight wall held by tabs.