Tools / Mould Design Generator
Mould Generator — Turn Any 3D Model Into a Print-Ready Mould
Upload an STL, STEP or 3MF file. Our servers analyse the geometry, build the cavity with your clearances and draft, add the feed system, venting and registration keys — and return print-ready mould STLs. The precision engine adds CAD-exact ±0.01 mm cavities and a silhouette-following parting surface. Searching for a mold generator? Same tool — "mould" is the British and Indian spelling, "mold" the American one.
Model
Drop your model here or click to browse
STL · 3MF free — STEP with Premium · up to 200 MB
Mould setup
Two-part splits along a parting plane. Four-part makes four wedge pieces that pull outward sideways — side undercuts (arms, ears, handles) demould from rigid moulds. Six-part adds top and bottom cap pieces for up- and down-facing pockets, with the cap positions auto-optimised to minimise relief. One-part is an open-top pour.
Block is a solid rectangular mould. Conformal follows the part shape — less material, faster print.
The axis along which the mould halves separate.
Flat plane at the parting position. Switch to Follow part for a CAD-style conformal parting surface that hugs the silhouette.
Cavity & fit
Mould material around the cavity. 6–10 mm typical.
Uniform offset around the part for fit and release.
Scales the cavity up for casting material shrinkage. Resin ~0.5–2%, plaster ~0%.
Conical taper applied while sweeping the cavity for demoulding. Set 0 if holes must stay perfectly cylindrical.
Feed system
Top pours straight down into the cavity. Side places the sprue beside the part with a runner along the parting line.
Shift the pour point away from the part center. Keep it over the part or the sprue lands blind.
Venting & air valves
Vertical channels that let trapped air escape and act as resin risers.
Registration keys
Bosses on the bottom half, matching sockets in the top half — keeps alignment perfect.
0.1–0.2 mm for FDM, 0.05–0.1 mm for resin.
Resolution & precision
Finer voxels capture more detail but take longer. Large parts at fine resolution are auto-coarsened to stay within server limits.
Standard precision is voxel-accurate: the cavity is exact to within a fraction of the voxel size above. Switch to CAD-exact for geometry-exact cavities at any resolution.
An online mould generator for 3D printed casting tools
Designing a mould by hand in CAD means offsetting surfaces, finding a parting line, cutting the block, adding draft and then rebuilding all of it every time the part changes. This mould generator does that work from the model itself. Upload the part, choose how it should split, and get mould halves that are demouldable by construction — with the cavity, sprue, air valves, vents and registration keys already in place.
What you get
- Print-ready STLs for every mould piece, oriented on your chosen pull axis.
- A report.json with part and cavity volumes, block size, voxel grid, parting height and any warnings the generator raised.
- Undercut relief measured in cm³, so you know exactly how much cleanup a difficult part will need before you print.
Mould or mold?
They are the same word. Mould is standard in British, Indian and Australian English; mold is standard in American English. Whether you searched for a mould generator, a mold generator, a mould maker or a mold design tool, this is the page you want — nothing about the tool changes with the spelling.
Who uses it
Sculptors and murti makers casting resin and plaster, jewellers producing wax patterns, product teams making short-run silicone tools, and hobbyists who want a rigid 3D printed mould instead of a hand-carved one. Navi3D builds and runs this tool in Navi Mumbai, and can print the finished mould for you in FDM or SLA.
Frequently Asked Questions
A mould generator turns a 3D model into a print-ready mould you can cast into. Upload an STL, STEP or 3MF file and the Navi3D mould generator analyses the geometry, builds the cavity with your clearances and draft angle, adds the sprue, vents and registration keys, then returns mould STLs you can send straight to a 3D printer. Americans usually search for this as a "mold generator" — same tool, same spelling difference as colour/color.
Yes. The free plan gives you one mould generation per day at standard 0.5 mm resolution with no login required. Premium (₹520 for 30 days) removes the daily cap and unlocks fine 0.3 mm resolution, CAD-exact ±0.01 mm cavities, the silhouette-following parting surface, four- and six-part moulds and STEP import.
Standard precision is voxel-accurate — the cavity is exact to within a fraction of the chosen voxel (0.3–0.8 mm grids). CAD-exact precision (Premium) then projects every cavity vertex onto the true offset surface of your original geometry using exact closest-point queries, so dimensional accuracy becomes about ±0.01 mm and no longer depends on voxel size, with edges and corners kept sharp. Draft, undercut relief and the feed system stay exactly as engineered.
A flat parting plane cuts the mould at one height. The silhouette option (Premium, two-part) instead splits the halves on a curved surface that traces your part's natural widest outline — the same parting-surface concept CAD mold tools use. The witness line lands on the part's own silhouette edge, and the registration keys, vents and runner follow the curve.
STL and 3MF files work on the free plan. STEP and STP import is a Premium feature. Files can be up to 200 MB, and the mesh must be watertight so the tool can define an inside to hollow out.
A two-part mould splits along a single parting plane — best for simple shapes. A four-part mould creates four wedge pieces that pull outward sideways, so parts with side undercuts like arms, ears or handles release cleanly from a rigid mould. Six-part adds top and bottom caps for up- and down-facing pockets, with the cap positions auto-optimised to minimise undercut relief.
The generated moulds suit casting materials such as resin, silicone, plaster and wax. Set the shrinkage compensation to match your casting material for an accurate fit.
Yes. Once you generate and download your mould STLs you can order them printed through the Navi3D 3D printing service in FDM or SLA, and we ship across India.
Both are correct — "mould" is standard in British, Indian and Australian English, "mold" is standard in American English. They mean exactly the same thing in casting and tooling. This tool works identically whichever spelling brought you here.