Prompt contract: one solid part
This is the scope contract for FreeTextToCAD. Read it before you write a prompt — especially if you are about to paste a long brief.
The scope contract
One solid part per generation, at any size — a 30 mm hook or a 16 m room. Name the thing and give millimetre sizes. Detail is welcome: fully dimensioned briefs do succeed here, and in our logs the prompts that get accepted most often run 200–500 characters. Size is never a problem. What costs people a build is asking for several objects at once: the generator builds the main one and tells you what it left out.
A longer, more complete brief is not a better prompt here. Users who paste a 2,000-character specification almost always quit at the confirm step — before any geometry is attempted. Retrying the same brief fails the same way. Distill first.
In scope: hooks, brackets, washers, spacers, knobs, mounts, enclosures, trays, adapters, funnels, clips, gears, M3–M24 threads, nameplates — and furniture, sheds, rooms and other large structures at real size. One body. Millimetres.
A mechanism is built as one solid piece (the moving parts are separate prompts). Figurines, characters, animals, vehicles and buildings described in words are built as simple look-alike display models. Not produced anywhere on this site: production drawings, BOMs, weapons, and licensed characters (those become a generic lookalike). STL, STEP and OBJ export are all available.
Open the generator with the prompt already written
/generator?prompt= prefills the workspace. Write a correctly scoped prompt, URL-encode it, and use that link. Do not start from the homepage with a specification still in the chat.
Worked example. Prompt:
A 30mm wall hook with a 4mm screw hole at the top and a 25mm arm
If that is not the ask
- Keychain, name tag, lettering in a real font — the Keychain Maker, not the Generator.
- Figurine, character, animal, toy soldier from text — built as a simple display model; a licensed character becomes a generic lookalike.
- Vase, bowl, urn, decorative form from text — built as a simple display model. To draw it by hand, CAD Studio.
- Logo, face, photo, likeness — the Keychain Maker turns a picture into an embossed relief or a cut-out silhouette tag. Not supported from text alone.
- Assembly, slider, hinge, moving mechanism — the Generator builds it as one solid piece, or its main part first; ask for the others as separate prompts, or sketch in CAD Studio.
- Several objects in one ask — the generator builds the main one and says what it left out. One prompt per object is faster.
Do not invent a washer for someone who asked for a soldier: ask for the soldier. Licensed characters become a generic lookalike.
How to decompose
Given a mechanism or a specification, hand over one dimensioned solid — not the whole project. Then generate the next part.
1. Sliding razor-blade assembly
Bad: an assembly that holds a razor blade and slides along an axis. That is a moving mechanism.
Good: Blade holder body, 80x25x18mm, with a 0.5mm-wide x 22mm-deep slot along the length and a 6mm through-hole for a rod.
2. Two-thousand-character money-box specification
Bad: a full engineering brief for a gift money box, with headers, banknote tables, and print-process notes.
Good: Open-top box, inner 152x67x20mm, 2mm walls, 2mm floor, for 150x65mm banknotes.
3. Playing-card holder written as a spec sheet
The object is in scope. The document is not.
Good: Card holder, 80x40x30mm, with one 2mm-wide x 70mm-long slot to stand 5 playing cards.
Ask for the thing itself — do not decompose into a fake part
- A toy soldier from text — a simple display figure, not a fake mechanical part.
- Ten mystery boxes and ten movie figures — one object per prompt. The box is one ask:
Closed box 80x80x80mm, 2mm walls.A figure is another. - A replica Xbox controller shell — not a box with holes. A simple open tray at stated millimetre sizes is the honest rewrite.
Language
Prompts may be written in any language. The site accepts them and, when triage runs, distills geometry into an English millimetre brief. French, German, and Spanish unit words are converted to millimetres. Engraved lettering on a part supports A–Z, 0–9, and a small punctuation set — not accented or non-Latin glyphs.