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mold option issues


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Posted · mold option issues


Attached please find a photo (name – s26) of a sculpture model I am trying to print as a mold. The second photo (name – "s26 print") is the inside view of the printed model.

As you can see, I am facing 2 main issues:

·      The print includes some holes. I think it's a result of lack of support. I couldn't add support inside the head (neither automatic, nor manual (Support blocker)). If it's possible, please let me know how.

·      The inside part of the head includes strings from wall to wall (bridge wasn't selected)

Both issues (holes and strings), prevent using this print as a mold.

·      How does mold option works? Does it create the model negative or just expand the model within mold width?

·      I didn't find a way to create a mold with 1 layer (meaning – the distance between the outside of the mold and outside of the model is - 0 mm). I intend to cast cement in the mold, therefore I want a minimal mold width

Is there a reason why Cura does not support slicing of an open model (like the attached one)? Load it to Cura result by the following error – "your model is not manifold. The highlighted areas indicate either missing or extraneous surfaces". Is there a way to do it?

Thanks a lot



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    Posted · mold option issues

    I have no experience with the mould-option. But why not make the mould yourself in CAD? Then you have all the freedom you want, and you can insert any desired features.


    - Draw a box around your model.

    - Subtract the model from the box, so you have a hollow (mould) shape of the model.

    - Provide pouring openings and funnels.

    - Provide venting openings for air to escape.

    - Provide flanges or screw-openings to assemble and clamp both mould halves later on.

    - Design a thin plate and provide alignment features on the edges it: blobs on one side, pits on the other.

    - Use that thin plate to cut the mould in two halves. So both halves of the mould will align correctly later on, thanks to the blobs on one side, and pits on the other.

    - Print both mould halves on their back. That is the advantage of using a box to start from: then you end up with two halves with a flat backside, easy to print. Print with wall-thickness and support-density as required for your castings. Concrete and gypsum will need stronger parts than foams, obviously.

    - Spray the mould with suitable mould-release spray for your materials. Then spray again.

    - Clamp both halves together, and ready to go.


    Then you have a professional 3D-printed mould. Very similar to hand-made moulds. All these features are very difficult to generate automatically; you can design them better manually.


    Watch out for exothermic casting materials (even gypsum): they might melt the mould. Use slow-curing or non-exothermic materials.


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