A box for a board, or for anything

Pick the board you are boxing (a Raspberry Pi 4, 5 or 3B+, a Pi Zero or an Arduino Uno) and the box is sized around it: posts under its mounting holes, a margin all round, and room above for the tallest connector. Or choose My own size and give the inside length, width and height of the space you need, with posts if a board has to sit on them. Either way you get a box and a lid, printed side by side on one plate.

Openings for ports and cables

Each of the four Opening sections cuts a rectangle or a round hole through one wall, the floor or the lid. You place it by looking at the assembled box from above: on the front and back walls a positive across moves it to the right, on the left and right walls it moves it toward the back, and height is measured up from the floor’s top surface. On the lid and the floor, across is left and right and the second setting moves the hole toward the back (positive) or the front, again as seen from above. The page tells you if an opening would run into a corner or over the rim.

The lid

• Screwed down puts a post in each corner, and four screws (M2 to M4) go through the lid into them. Self-tapping screws cut their own thread in the plastic; the pilot hole is sized for the screw you pick. It opens and closes many times, and the lid can’t slide off.
• Press-fit lip gives the lid a thin ring that slides inside the walls. There is nothing to lose, but it relies on the fit clearance, the one setting that depends on your printer: too small and the lid won’t close, too large and it rattles. Print the Press-fit lid fit test preset, a small box in a few minutes, and adjust by 0.05–0.1 mm until it closes with a light push.

Boards, and how much to trust the numbers

The Raspberry Pi hole pattern (four holes 58 × 49 mm apart, 3.5 mm in from the edges) and the Pi Zero’s (58 × 23 mm) are the published ones. The Arduino Uno’s four holes are taken from Arduino’s own board drawing, and they are not on a tidy grid; clones vary by a few tenths of a millimetre. Screws in a pilot hole forgive that, but measure your board and check it against the box before printing a big one, or choose My own size and enter the hole spacing yourself. The connector openings in the presets are a starting point too: reposition them if your case or cables need different room.

Printing

• Orientation: the box is printed with its opening up and the lid flat-top-down, as they are laid out; no supports are needed.
• Settings: a 0.4 mm nozzle, 0.15–0.2 mm layers and at least three perimeters. Two millimetre walls make a stiff box; go thicker for a large one.
• Heat: PLA softens at about 55 °C. A Raspberry Pi 4 under load runs warmer than that, so print its case in PETG or ABS and add ventilation slots in the lid, the sides, or both.
• It is not waterproof and has no seal.

FAQ

Which Raspberry Pi models fit? The Pi 4, 5 and 3B+ share a 85 × 56 mm board and the same mounting holes, so one setting covers all three. The Pi 5 runs hotter, so give it ventilation and, if you use the official cooler, more height.

Can I fit a HAT or a fan on top? Yes: raise the space above the board. Stacked boards and coolers are taller than the bare board, so measure the tallest thing you’ll fit.

Where do the wires go? Add an opening in a wall for the cable, or a round one for a cable gland or a panel-mount switch, LED or button. There is room for four openings, plus ventilation.

Can I edit it in CAD? Yes: the STEP button gives an exact model of the box and lid as two solids, with true round holes and posts, so you can add your own cut-outs and keep the rest.