I am new at SU and am trying to create a model to 3D print in plastic, which I can then use as a mould to cast gypsum. (Think: The inside surface of a mask.) So, I’ve created an example of the object I want to cast in gypsum. Now, I need to make the inverse of that (or in other words the negative space of the object or a shell of the object’s surface) to print in plastic- so that when I fill the 3D-printed plastic with liquid gypsum , it will cure into the shape I’ve created in this file: Test .skp (7.6 MB)
How can I make something that is simply the shell of the top surface of the object? Please help! Thanks in advance!
You need to make it a solid (watertight) in order to print it, and once it is a solid you can subtract it out of a block which you can print to make the mold.
I’ve only cast bronze and aluminum, so I don’t know what kind of release geometry you need for acrylic, but you should consider that as well when making the form.
I replied to an earlier post from you but that thread seems to have disappeared. As Mike says, if you clean up your model to make the objects solid you can use Subtract from the Solid Tools to subtract the model from a solid block. I made this example from one of my models to show but your thread was gone when I came back.
A common procedure for gypsum casting would be, too, to print the positive object and then use silicone to cast the mold from that object. I understand the mold needs some flexibility so that the finished product can be separated from it, and I don’t know if the available 3D printer filaments can provide that.
