Upload an STL, get a ready-to-print two-part mold in your browser — free, no CAD.
Turn an STL into a mold for resin, concrete, soap or candles in a few minutes.
Open the Mold Maker — free🔥 63 models generated
You have the model. Now you want copies in resin, wax or concrete.
Learn Fusion 360, fight Blender for an evening, or stack boolean tricks in your slicer and hope the halves line up.
Drop in your STL, check the split, download the two halves. The block, cavity, pour hole and keys are built for you.
Drag it in, or load the sample model to try it first. Broken meshes are repaired automatically, and heavy scans are simplified.
Rotate the model to set the split direction, then pick wall thickness, pour hole size and how the halves lock together.
Get both halves as STL or 3MF, and check they fit the printer you picked.
Print the halves, band them together, and pour.
Rotate the model with sliders or drag the rings on screen; a live plane shows where it will split.
4–20 mm opening, moved along the seam to where you want to pour.
3–10 mm of rigid printed wall.
Tongue & groove seals liquids best; pins are simpler for rigid casts.
0.1–0.5 mm gap so printed parts actually fit together.
How much wax, resin, plaster or concrete to mix.
Resin is one of the most popular things to cast in a printed mold. The two-part box mold works best for shapes that pull apart cleanly along one seam, like figurines, knobs and display pieces. Choose tongue & groove so the seam holds liquid.
Concrete takes a printed mold well: it cures cold, so plain PLA is fine and PETG lasts longer. For thick mixes, open the pour hole wide.
Plaster works the same way — dry it slowly and evenly, away from direct heat.
Read more →
Melt-and-pour soap isn't as hot as wax, so a rigid printed mold works. It suits soaps with a raised shape or logo that you want to repeat exactly.
Two-part molds are a classic way to make pillar and shaped candles.
Need a flexible silicone mold instead? Try the Silicone mold box generator →
Yes. You can make molds and download your first 3 files without an account. A free account gives you 5 downloads every week.
No. You upload an STL and adjust the mold with sliders. The block, cavity, pour hole and alignment keys are generated for you.
Not safely for most waxes. PLA starts to soften around 60 °C, and many waxes are poured hotter than that, so the mold can warp. Print candle molds in PETG, ABS or ASA, and pour at the low end of your wax's range.
Read more →Yes, resin grips layer lines and can lock into the plastic, so use a mold release every time. Smoother inner walls also help the casting come out clean.
Read more →Every layer line in the mold shows up on the casting. Print the mold with a lower layer height and more wall perimeters, then sand or coat the inside of the cavity before you cast.
Choose your printer in the generator and the bed outline on screen matches it, so you can see whether the halves fit before you download. If they don't, scale the model down or reduce the wall thickness.
Almost always because it dried too fast or unevenly — heat or airflow on one side makes one face shrink before the other. Dry plaster slowly and evenly, away from direct heat.
Read more →No. The mold is built in your browser, on your own device. Your STL is never sent to a server.
Free account — 5 downloads every week.
