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3D printable box generator
A box generator that starts from what goes inside
A box is only right when it fits what you put in it: the batteries, the SD cards, the screws, the shelf it sits on. SpeakCAD gives you two ways to get there. Start from the open box shape and type its width, length, height and wall, then add dividers, a label and a cable hole with the hand tools, free, download included. Or describe the box to the AI with its contents and its lid, and it builds the compartments, the pockets and a lid that closes. STL, 3MF or G-code sliced for your printer, on a phone or a computer.
How it works
From the inside size to a box on the bed
Measure the space and the contents first: the inside size is the number that matters, the outside follows from the walls.2
Add dividers, a label, a hole
A divider is an Add: a rectangle 1.6 mm wide, as long as the inside, standing on the floor, placed in millimetres from the walls; Duplicate turns it into a row. Text writes a raised or engraved label on the front, Hole drills a cable or drain hole, Extrude makes the walls taller.3
Check the render
A hand edit rebuilds in your browser in a few seconds; with the AI, the first render usually appears within a minute or two: a new part gets deeper reasoning through the geometry, and small edits land in seconds. Tap a face to read its size and check the inside against your contents. Every hand edit is a numbered version: Undo steps back one at a time, down to the empty model for a model you started by hand, as long as the AI has not answered on it.4
Download and print
A box shaped by hand downloads free as STL or 3MF; a box with AI work in it spends 4 credits. G-code comes sliced with the official OrcaSlicer profile of one of 380+ printers. Ask for the box and its lid side by side and they come in one file.What one box costs
| Step | Cost |
|---|---|
| Live demo: 3 AI edits of a real part, no account | Free |
| The open box shape, its sizes typed in the viewer, dividers, a label, holes and rounded corners by hand | Free, and the STL or 3MF downloads free |
| Describing the box with its lid (one AI request) | 2 credits |
| Each change by chat | 2 credits |
| Typing a new number in the dimensions panel, undo | Free |
| STL or 3MF download of a part with AI work in it | 4 credits; small fixes after it re-download free |
| G-code sliced for your printer | +5 credits per slice without Pro or Unlimited |
| Maker | $7.99 a month: 60 credits a month, about 6 parts with a couple of edits each; cancel anytime |
| Pro | $14.99 a month: 200 credits a month, sliced G-code included |
| Unlimited | $39.99 a month: unlimited requests and downloads |
Box descriptions that render right the first time
Inside size, contents, lid, walls. Each opens in the editor with the text already typed; measure your own contents before printing.“A box for 20 AA batteries standing upright in a 5 x 4 grid of 15 mm round pockets 40 mm deep, 1.6 mm walls, a sliding lid in grooves with 0.3 mm clearance and a thumb notch.”
Open this prompt in the editor“A storage box 120 x 80 x 50 mm inside, 2 mm walls, three compartments in a 1:1:2 ratio along the length, a friction-fit lid with a 0.25 mm clearance lip, a label recess 50 x 15 mm on the front.”
Open this prompt in the editor“A screw organizer box 160 x 100 x 30 mm inside with 12 equal compartments, rounded inside corners for scooping, and a lid held by four 6 x 2 mm magnets in pockets 6.2 mm across and 2.2 mm deep.”
Open this prompt in the editor“A box for 10 SD cards and 20 microSD cards: SD slots 33 x 2.6 mm, 20 mm deep, microSD slots 16 x 1.4 mm, 10 mm deep, in rows with a 1.5 mm rib between slots, and a snap-fit lid.”
Open this prompt in the editorTwo ways to make the box
- By hand, free. Start from the open box and type its sizes in the viewer. Add a divider (a thin rectangle standing on the floor) and Duplicate it into a row; write a label with Text; drill a hole with Hole or cut a slot with Cut; Extrude the rim for taller walls; round the corners. A box shaped only by hand downloads free as STL or 3MF from a free account. The hand tools page shows each tool.
- With the AI. Describe the contents and the lid: compartments by ratio, a pocket per object, magnets, a sliding or snap-fit lid, stacking feet. The AI writes the box as a parametric model, so every size stays a number you can change afterwards.
Inside sizes for common contents
Measure your own: brands differ by a few tenths of a millimetre. Add 0.3 to 0.5 mm per side for things that should drop in and out.
| Contents | Size (mm) | Pocket to ask for |
|---|---|---|
| AA cell | 14.5 across, 50.5 long | 15 mm round, 40 mm deep to leave a grip |
| AAA cell | 10.5 across, 44.5 long | 11 mm round, 35 mm deep |
| 18650 cell | 18.4 across, 65 long (protected cells up to about 69) | 19 mm round |
| SD card | 32 x 24 x 2.1 | 33 x 2.6 mm slot |
| microSD card | 15 x 11 x 1.0 | 16 x 1.4 mm slot |
| Credit card | 85.6 x 54 x 0.76 | 87 x 56 mm inside for a stack |
Lids that close
| Lid | How it holds | Clearance to ask for |
|---|---|---|
| Friction lid | A lip inside the walls | 0.2 to 0.3 mm |
| Sliding lid | Grooves in two walls | 0.3 to 0.4 mm |
| Snap-fit lid | Clips on the walls | 0.2 to 0.3 mm, a test print first |
| Magnetic lid | Magnets pressed into pockets | Magnet size + 0.2 mm |
| Screwed lid | M3 screws into corner pillars | 3.4 mm holes in the lid |
SpeakCAD is the only AI 3D editor that calibrates itself to your printer: Fit Check cuts a five-minute test slice from the part that must fit, you report too tight, perfect or too loose, and every model after that is built with the clearance your printer needs. For a box, the test slice is the lid's lip or groove, printed in a few minutes before the whole box.
A box, a tray or an enclosure?
- A drawer tray or bins for a drawer: the organizers use case and the ready-made organizers, which open in a free account and resize in the viewer.
- A case for a circuit board, with screw bosses on its holes and cutouts at its ports: the enclosure generator.
- A holder shaped to one object (a spray can, a tool, a phone): the holder generator.
What it costs
A box made by hand from the box shape downloads free. A box with AI work in it uses credits. Start with Maker: 60 credits a month for $7.99, cancel anytime. Shaping a part by hand (a hole and its screw head, a cut, an added tab, raised or engraved text, an extruded face, rounded corners, and copies in a row, a grid or a circle), turning it around in 3D and changing its numbers in the viewer are free, and so is downloading a part you shaped by hand; each AI request (a new part or a chat edit) spends 2 credits, whichever model answers (up to 10 on a very large model); a download of a part with AI work in it spends 4 credits (+5 for G-code sliced for your printer without Pro or Unlimited); small fixes after a download re-download free.
Questions
For a plain box of a given size, a template generator with sliders is enough. For a box sized to its contents, with dividers, a pocket per object and a lid that fits your printer, SpeakCAD works from the numbers you give: start from its box shape and shape it by hand, free, or describe it to the AI. It downloads STL, 3MF or G-code sliced for 380+ printers, on a phone or a computer.
Yes. Describe the lid with the box: a friction lid with a lip, a sliding lid in grooves, a snap-fit lid, a lid on magnets or on screws. That is an AI request (2 credits). Ask for the box and the lid side by side to get them in one file.
Yes, two ways. By hand: Add a rectangle 1.6 to 2 mm wide standing on the floor, as long as the inside, then Duplicate it into a row of dividers, every position in millimetres. Or ask the AI for compartments by count or ratio, with finger notches or rounded inside corners.
Yes. The Text tool writes raised or engraved letters on a flat face, up to 40 characters in one bold sans font, with the letter height and depth you type. For a recess to take a printed or paper label, ask the AI or Cut a shallow rectangle.
The lid is built with FDM clearances (0.2 to 0.3 mm for a snug fit, 0.3 to 0.4 mm for a sliding one). Printers differ, so Fit Check prints a thin slice of the lid's lip or groove first; you report too tight, perfect or too loose, and your printer's calibration goes into every model after that.
Yes. SpeakCAD runs in Safari on iPhone and iPad and in Chrome on Android: type the sizes, tap the faces, and the STL, 3MF or G-code lands in Files or Downloads.
A box shaped by hand from the box shape, its download included, is free with a free account. With the AI, describing the box is one request (2 credits), each change by chat another, and a download 4 credits; typing a number in the viewer spends nothing. A new free account also gets its first AI request and that part's first change on us (not offered in every country); downloading the part spends 4 credits, like any AI work. G-code sliced for your printer is included in Pro and Unlimited and spends 5 extra credits per slice otherwise.
Read more
Organizers and storageDrawer trays, bit holders and bins sized to the millimetre.Ready-made organizers in the libraryTrays, bins and boxes that open in a free account and resize in the viewer.Enclosure generatorA case for a circuit board, with bosses, cutouts, vents and a lid.The hand toolsHole, cut, add, extrude, text, round and measure, every size in millimetres.Add text to a 3D printA raised or engraved label on the front of the box.Fit CheckTest the lid on a five-minute slice before printing the whole box.