Jewelry wax model
Custom jewelry making starts with jewelry wax models. The jeweler uses a special kind of modeling wax to create an exact replica of the piece of jewelry the customer is looking for. Most jewelers make this model painstakingly by hand but custom jewelry wax models can be made much more easily by using 3D modeling software.
The software make changes easy and stores the models so they can be reused and modified quickly for new customers. The picture below shows a 3D model of a piece of jewelry created around singer Avril Lavigne's skull logo.
Models created on the computer can be saved to a file format called “STL”. The STL file is read by a machine called a wax printer, which creates a perfect wax model by spraying jets of wax, layer by layer similar to an ink jet printer. Wax printers can create complicated wax models much faster than by hand. They can easily “print” engraving at the same time as they make the wax model.
Jewelry Casting Machine
Once the wax model is complete and approved, the jeweler places the wax model in a jewelry casting machine and fills the machines container with plaster. The plaster is allowed to harden around the wax model. An access hole is made so that molten metal can be poured in. Molten gold is then poured inside the plaster mold which immediately evaporates the wax model. This method is named “The Lost Wax process”.
The last step is to spin the plaster mold with the molten gold inside at high speed so that centrifugal force makes all the gold fit into all the nooks and crannies in the mold. Part of the jewelers skill involves knowing how to make wax models that will cast easily. Complicated shapes may be possible on the computer, but the jewelers needs his experience to know what can be cast and what cannot.