Molde para peças de silicone

What this does

It turns your model into a mold you 3D print and fill with silicone, so the silicone itself becomes the finished part. You get three printed parts: two halves split through the model, with keys that line them up and holes for M4 bolts, and a lid that closes the flat end. The lid has a pour funnel in the middle and small vents all round the edge, so the silicone goes in and the air comes out.

Use it for soft, solid silicone parts: grips and handle covers, bumpers and feet, bottle stoppers, squishy figures and stress toys, prop and cosplay parts, replacement rubber pieces. Everything runs in your browser. Your model is never uploaded anywhere.

How to use it

1. Upload your model and set which way is up. The end on the plate is where the lid goes, so put the flat end of your part down. A round model? Raise Flat base to cut a flat end onto it.
2. Generate. Check the silicone amount and that the parts fit your printer.
3. Print both halves parting face up and the lid flat face down, all without supports. For a smooth part print the halves at 0.12 mm or sand and seal the cavity.
4. Coat the inside with a release agent, close the halves, bolt or clamp them and seal the outside seam with clay or hot glue.
5. Stand the mold flat end up. Either press the lid on and pour the degassed silicone slowly through the funnel until it comes out of the vents, or, with thick silicone, fill the open mold to the brim and press the lid on last so the extra squeezes out of the funnel and vents.
6. Let it cure, open the mold and trim the seam and the pour stub.

Which silicone

Silicone	When
Platinum cure, Shore 00-30 to A-20	Soft, flexible parts. Use platinum cure for anything that touches skin or food. Test a small batch against your print first: some resins and sealers stop it from curing.
Tin cure	Cheaper and cures on almost anything, fine for parts that do not touch skin or food.
Harder silicone, Shore A-30 and up	Feet, bumpers, gaskets. Harder silicone needs more draft to come out, so avoid deep undercuts.

Settings

Setting	What it changes
Wall	Plastic beside the cavity. Thicker is stiffer and gives the bolts more room; thinner prints faster.
Flat base	Cuts the model flat this far above its lowest point. Needed when the model has no flat end to pour through.
Pour hole	The funnel's diameter at the cavity. Wider pours faster; thick silicone needs at least 10 mm.
Cupped underside	A shallow dome on the lid, so the part's flat end is slightly hollow. It saves silicone and lets the part stick to a smooth surface.
Follow the shape	The halves follow the outline of the model instead of being a full box. Uses much less filament.
M4 bolt holes	Holes through both halves for M4 bolts and nuts. Turn them off to clamp the mold instead.

Common problems

The silicone did not cure next to the mold

Platinum silicone is inhibited by some resins, sealers and sulfur clays. Use a PLA or PETG print, seal with a coating your silicone's maker lists as compatible, and use a different clay for the seam.

The part has bubbles at the top end

Air was trapped under the lid. Pour slower in a thin stream, keep pouring until silicone comes out of every vent, and degas the silicone first if you can. If the tool warned about a flat overhang, tilt the mold and tap it while you pour so the bubble can slide out.

The part shows the print lines

The cavity surface becomes the part's surface. Print the halves at 0.12 mm, or sand the cavity and brush on a thin sealer before the first pour.

The mold leaks along the seam

Tighten the bolts evenly and run a bead of clay or hot glue along the outside of the seam before pouring.

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