Why 3D design and printing is a better way to make slip casting molds

I dread the traditional mold making process, the mess, all the supplies and tools involved. I am a potter, I make functional ceramics. I am not a mold-maker, but 3D design and printing have put it within my reach. This way more fun! There is no stopping this, it’s the future.
-I spend most time on design, pouring the plaster or rubber takes minutes.
-Many fewer tools and supplies are needed, the process is less messy, as easy as downloading a file, printing it and pouring in plaster - this is doable in my kitchen! I don't even need mold soap!
-Sanding of flat mating faces is possible (for better seams than I've ever had). This is because natches can be added later (using embeds).
-I can make my own natches and interlock schemes.
-No spare is needed, the 3D-printed pour spouts work better.
-The range of shapes seems limitless. Especially because designs can be split up into pieces, each printed in optimal orientation (and glued together).
-I make molds through multiple design-print iterations. 3D makes do-overs or changes in design as easy as a reprint and plaster-pour. So, I can make a mold just to test an idea!

Related Pictures

3D Printing Artifacts on a Bowl Model.

When are these a problem? When are they not?

This picture has its own page with more detail, click here to see it.

3D printing is resetting and revolutionizing all fabrication industries. It brings exciting new capabilities, especially in ceramics. Each disadvantage is being addressed and solved. This stair-casing in the surface, or more correctly termed "printing artifacts", is often cited as a reason for not even considering the process. But here is why that view could rob you of a great opportunity:

For prototype molds (which are so much easier using 3D techniques), this issue can be completely ignored.
Even in production, this can be tolerated when opaque glazes hide it and when routine ribbing and sponging reduce it to a non-issue.
Only certain parts of most pieces exhibit this issue, the more vertical surfaces (and fully flat ones) are smooth. Further, since this is a jigger mold, the inside shape is formed by the rib and is smooth. Likewise with slip casting molds, the inside surfaces are pour-formed, and thus smooth.
For production molds, 3D printing is just the first step to creating plaster or rubber case molds. During the multistep process, the artifacts can be removed. For example, this is a plaster model of the outside shape of the piece; it is part of a hybrid mold (attaching to a 3D printed clamping baseplate and mating side rails). Thus, this can be tooled completely smooth (before soaping and use in making production molds).
In some cases, the artifacts actually add to the aesthetics of the final piece and can be amplified with the right glazes.
We have not noted release issues on molds having artifact surfaces when slip casting clays of sufficient plasticity are employed.

Realistically, the new capabilities of 3D address traditional mold making process weaknesses that we have always just accepted. This new technique brings capabilities into the hands of even a hobby potters that seasoned mold makers only 10 years ago would envy.

Bottle calibration mold demos novel casting methods

Plaster molds held together without straps

This picture has its own page with more detail, click here to see it.

Three slip casting methods are examples of the flexibility potters have compared to manufacturers (especially for small molds like this).
1) 3D-printed locks are stuck on to hold the mold halves together. The casting slip itself adheres them. Dipping the flat surfaces and attaching them takes seconds. This method enables aligning halves accurately and then locking them into place.
2) The 3D-printed pouring spout is also attached using the slip (it also helps hold the mold halves together) and acts as a reservoir and pour-out indicator. Thus, this mold needs no spare.
3) There are no natches (the halves were poured into disposable 3D printed PLA masters - and mate perfectly and align easily).
These three factors simplify the mold design, reduce mold size, improve the fit of parts and simplify pouring, demolding and cleanup for this specific type of piece.

Videos

Links

Projects	Beer Bottle Master Mold via 3D Printing A project that took several years of failures and blind allies and is finally coming together - so much simpler than expected!
Glossary	Side Rails Side rails are the containment used when pouring plaster molds. We 3D-print these to custom fit each mold.
Glossary	Casting Slip Casting slips are among the easiest clay bodies to make yourself. The ability to make and tune your own will open many doors in your production process.
Glossary	Pour Spout Plaster molds intended for slip casting have a spare at the top to act as a reservoir. This enables overfilling the mold to accommodate the dropping slurry level. 3D-printed spouts make a spare unnecessary.
Glossary	Mold Natches At digitalfire we are big fans of slip casting and want to help people and companies (even hobbyists) to integrate it into their production.
Typecodes	3D printing problems 3D design and printing for mold making in ceramics bring exciting new capabilities. Awareness of the issues and knowing how to mitigate each is a must. 3D is resetting all fabrication industries and engineers are solving every problem, you can too.

Got a Question?

Buy me a coffee and we can talk