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Box divider generator for interlocking inserts

Free in your browser, with no upload or signup. Keep small handmade products apart inside a box. Generate the crossing strips and half-depth slots for a custom grid insert, sized to the box you already have.

A fitted insert for an existing box

Measure the usable inside size of your box. The generator divides that space into equal clear cells, allowing for the thickness of every strip. Across strips have slots opening from the top; front-to-back strips have slots opening from the bottom. They meet at half height and sit flush.

Measure the material, then test the fit

Slot width is the measured material thickness plus the total extra clearance you enter. There is no laser kerf compensation: allow for your machine in its software and cut one crossing pair before the full set. Card, corrugated board, plywood and acrylic all behave differently.

Worked example

A 240 × 180 mm box, 2 mm board, 0.2 mm clearance, three columns and two rows: one across strip 240 mm long with two slots, and two front-to-back strips 180 mm long with one slot each. Slots are 2.2 mm wide and 30 mm deep on 60 mm strips; each cell is 78.67 × 89 mm clear.

Using the files

The SVG keeps cut lines and labels in separate groups. Hide the labels or set them to engrave. Keep millimetre units on import. Strips are laid out one above another for checking, not nested onto a stock sheet. These are packing separators, not certified protective packaging.

Questions

Is this the same as the box maker?

No. The box maker produces an outer enclosure. This makes an open grid of interlocking strips that stands inside a box you already have.

How should I choose slot clearance?

Measure your stock and test one crossing pair. Clearance is extra width across the whole slot, not per side. Machine kerf and material compression must be checked physically.

Can I work in inches?

Yes. Switch the units to inches; the SVG is still exported at true size.