Living hinge panel: parametric template

Parameters

Open in the editor opens the design with these defaults; change them afterwards in Modify › Parameters, and everything that depends on them follows. Opened from the editor’s template library instead (New ▾ › New from template…), the template asks for its values first and checks them against these ranges and against each other, and Copy link gives an address that opens it with your values.

Name	What it sets	Default	Range
`W`	Panel width	180 mm	80 to 400 mm, steps of 1
`H`	Panel height	100 mm	40 to 300 mm, steps of 1
`thickness`	Material thickness	3 mm	1.5 to 6 mm, steps of 0.1
`band`	Hinge band width	40 mm	10 to 120 mm, steps of 1
`pitch`	Slit spacing	2.5 mm	1.5 to 6 mm, steps of 0.1
`slitLen`	Slit length (target)	20 mm	8 to 40 mm, steps of 0.5
`bridge`	Bridge length	3 mm	1.5 to 8 mm, steps of 0.1
`slit`	Slit width	0.5 mm	0.2 to 1.5 mm, steps of 0.05

Notes

A band of straight slits in staggered columns lets a stiff sheet bend round a curve - the classic living hinge for laser-cut boxes with rounded corners, book covers and lamp shades. Outside the band the panel stays flat and stiff.

Band is the width of the flexible zone, centred on the panel. Slit spacing is the distance between columns: closer columns bend tighter but make the panel weaker. Each column has slits about Slit length long with Bridge length of solid material between them, and every other column is offset by half a slit so the bridges never line up. The columns at the band's edges run their slits off the panel's top and bottom edges so those edges bend as well.

Slit width is drawn as the width of each cut. Lasers remove their kerf anyway, so set it near your kerf (0.2 to 0.5 mm); the outline is exported as thin rectangles. Plywood with a fine, even grain (birch) and 3 mm MDF flex best; bend along the slits, across the grain where you can.

To bend the panel round a radius R through an angle θ, the band needs to be about R × θ (in radians) long: a 90° corner of radius 25 mm needs about 40 mm. Export the outline with Save As DXF from the sketch's right-click menu.