MoldForge

MoldForge turns any 3D model into a print-ready mold, right inside Blender: watertight, registered parts you can slice and print, with live silicone/resin volume and weight estimates so you know how much to mix before you pour.

Three mold types

• Silicone Pour Box. Print a thin-walled jacket, nest your master inside, and pour liquid silicone into the gap. Includes the glove / mother-mold workflow (a thin skin with registration keys) and an MF_Skin preview that shows exactly the silicone you'll pour.
• Direct Printed Mold. The printed pieces are the mold; cast resin, wax or plaster straight in. Choose a Hugging shape (least material) or a Block (easiest to clamp and stand).
• Tray / Open Pour. A one-part open pan for flat and relief objects (text, logos, coins, medallions): embed the object and pour silicone over it for a flexible stamp, or frame a real object. Rectangular or material-saving rounded-hug outline.

What it does

• Self-registering splits: auto-oriented contoured parting that follows the model, or a flat parting with cone keys or interlocking teeth.
• Multi-part for undercuts: split into 3 or 4 radial wedges that each pull straight out.
• Clamp wings and bolt holes that hug the body and run up the funnel; an optional horizontal split adds a bolted, insert-ready flange ring for tall molds.
• Real pour funnels: adjustable throat, height and mouth flare, bored clean into the cavity, plus air vents.
• Detachable keyed base plate with a dial-in fit clearance so the printed parts actually click together.
• Volume and weight estimates in ml and grams, with material-density presets (Dragon Skin, Mold Star, Smooth-Cast resin, plaster, and more).
• Robust on messy meshes: heals and auto-remeshes non-manifold or heavy scans, validates that every part is a watertight single solid, and never writes a broken STL.
• One-click STL export.

Getting started

1. Open the MoldForge tab in the 3D viewport sidebar (press N).
2. Select your model, pick a mold type, and tweak the options, or keep the smart defaults.
3. Click Generate Mold, then Export the parts as STL.

Sizes are in scene units (1 unit = 1 mm at the default scale). Free and open source (GPL-3.0).