Box with lid generator

1. Set the inside size: measure what has to fit and add a millimetre or two.
2. Pick the lid: lift-off (a lip that sits inside the walls), sliding (slides in from the front along grooves), or none for an open tray.
3. Add compartments if you want them, and round the corners.
4. Download the box and lid as one STL, a 3MF, or a zip with each part separately.

The fit is the gap between lid and box on each side. 0.2 mm suits most well-tuned printers. If the lid is too tight, go up to 0.3–0.4 mm; if it rattles, go down to 0.1–0.15 mm. Printing a small box first (the size doesn't change the fit) saves filament while you find your number.

• Lift-off lids print flat with the lip facing up, so no supports are needed.
• Sliding lids print flat; the grooves in the box print as small overhangs, which most printers manage without supports.

Wall thicknesses that are multiples of your line width print cleanest: with a 0.4 mm nozzle, 1.2, 1.6 or 2 mm (3, 4 or 5 lines). For boxes that get carried around or dropped, 2 mm walls and a 2 mm floor are sturdy in PLA or PETG.

Want a name or a label on it? Download the lid and put text on it with Add text to STL. For holes (a cable, a hinge pin) use Merge and cut STL.