Finger joint box generator

Generate a laser-cut finger-joint box in seconds: closed box, open tray, tray with lift-off lid or divided tray. Enter outer size, material thickness and kerf, download the SVG with every panel laid out flat.

Pick the kind of box, type its outer size, your material thickness and the kerf of your laser. Every panel comes out at the right size with interlocking fingers already drawn, in one SVG you can send straight to the laser or drop into the nester.

The four kinds

• Closed box. Six panels, every edge finger-jointed. Glue it shut, or saw the lid off afterwards for a hinged box.
• Open tray. Five panels with straight top edges: trays, bins, planters, drawer inserts.
• Tray with lift-off lid. An open tray plus a shallow second tray that drops over it, with the clearance you set.
• Divided tray. An open tray with an egg-crate divider grid that slots together and drops in.

How the joints are laid out

Each edge that meets another panel is divided into an odd number of equal fingers. The bottom and lid are notched all the way round, the front and back carry tabs along their bottom and top edges, and the two sides carry tabs on every edge. Put together, every corner of the box is filled by exactly one panel, so there are no gaps and nothing to trim. An open tray simply leaves the top edges straight; the lift-off lid is a second, shallow tray built the same way; the dividers are plain panels with half-depth slots that cross like an egg crate.

Kerf and fit

The laser removes a thin line of material along every cut, the kerf. Without compensation a slot comes out wider than drawn and a tab narrower, and the joint rattles. The generator grows every tab by the kerf and shrinks every slot by it, divider slots included. Enter the kerf you measured on this material and this lens; if you have not, cut our kerf test gauge first.

Material and finger size

• 3 mm plywood or MDF: fingers 8–12 mm wide look right on boxes up to about 200 mm.
• 6 mm: fingers 12–20 mm.
• Acrylic: use a smaller kerf (0.1 mm or less) and glue with solvent cement; the fit should be snug, not forced.

Related tools

• Living hinge generator: Six slit patterns, straight to honeycomb, that let a flat sheet bend, sized to your panel.
• Kerf test gauge: Slot gauge and reference square to measure the kerf of your laser on any material.
• Material test grid: Power × speed squares, one layer each, to dial in a new material in one burn.