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January 2000

Precious Metals & Bench: Metalsmithing

The CAD/CAM Revolution

Now within reach of custom-jewelry designers who work in jewelry stores, this equipment can save time and build business

The jewelry industry is keenly aware of the profound effect diverse technology will have on its future. One technology destined to cause a revolution is CAD/CAM, which stands for computer-aided design/ computer aided-manufacturing.

Thought of most often in connection with large-scale production, CAD/CAM also allows smaller-production designers and jewelry manufacturers to provide unique designs at mass-production prices.

The greatest cost of a one-of-a-kind piece or small production run is the labor in creating and perfecting the original model. Traditionally, someone hand-carves a wax model or painstakingly fabricates a white metal model. Once the model is made, its cost is spread out over the number of pieces that will be made from it; for example, larger runs are more profitable than small ones because the cost of making the model is spread over more pieces.

The expense of models lies mostly in the time it takes to make them. It takes three to 10 hours to carve a good-quality wax model for a single custom piece or small production run and up to 50 hours for a model used in large-scale manufacturing. The difference arises because the custom jeweler stops adjusting the wax model at a certain point; even if a small problem remains in the model, the jewelry can be fixed once it's cast. Large-scale manufacturers, however, scrap any flawed copies and start over because it would be too costly to correct flaws in the mass-production pieces.

Enter Rapid Prototyping

Rapid prototyping refers to the creation of a three-dimensional model that can be evaluated during manufacturing before tooling. Some of these technologies are laser-driven and others are CNC-based (computer numerical control, otherwise referred to as 3, 4 and 5 axis milling).

After creating a design using CAD programs, I use the Sanders ModelMaker-II to make my models. This machine has the finest surface resolution in rapid prototyping and produces combustible models. The models can be investment-cast, which fits naturally in jewelry manufacturing.

The virtual models created in CAD programs can be downloaded to the ModelMaker-II for manufacturing. A proprietary technology slices the virtual models in a process called sterolithography.

Once the files are sliced, the ModelMaker-II uses inkjet technology to print each layer in a plasticized wax. Once one layer is complete, the table drops down and the next layer is printed on top of the last.
There are two waxes: green wax for the model and red wax that supports overhanging geometries and is dissolved once the model is built.

The build can comprise any combination of pieces. Building a single ring can take five to 13 hours, depending on how thick you make your slices. The thinner the slice, the finer the surface quality and the longer a piece takes.

Economies of Time

If the machine takes as long to make a model as a human modelmaker, where are the savings? Usually, a single ring isn't built alone. A build with 10 rings can take 35 to 70 hours, but the machine can work 24 hours a day while a craftsman goes home after eight.

You also gain consistency and the ability to create variations on a theme. And you can design free from the constraints of conventional reduction-based modelmaking. Instead of reducing a solid block of wax, the models are built so you can achieve geometries once considered impossible.

Rationalizing Cost

This technology isn't cheap – the entire setup can run $75,000, not including training on modeling using CAD. But consider these savings:

  • Assume a three-year life of the machine. At $25,000 per year plus $30,000 to hire a CAD designer who can run the machine, you have the custom-manufacturing capability to produce new lines of jewelry continuously. The time to market is weeks instead of months.
  • Custom work and small-run production can be priced competitively with mass-produced pieces. Of course, mass producers also have this technology, but if price isn't a factor, superior design will win the day.
  • Small creative jewelers can markedly increase productive output. Jewelers also can design in lower price points, which used to be difficult because the jewelry's price had to include the cost of making the model.
  • Increased custom design work using CAD/CAM will individualize an independent jewelers' business, fight branded goods and compete against Internet sales of generic jewelry.

Final Considerations

CAD/CAM requires an investment in money and effort. It won't create designs for you and can't distinguish good-quality jewelry from bad.

CAD operators most likely will be goldsmiths or jewelry designers who already understand such factors as necessary wall thickness or structural integrity of various prong lengths.

It's unknown whether independent jewelers will pool CAD/CAM resources or whether small manufacturers will offer more cost-effective custom-design services. For example, your staff could learn CAD and then send individual jobs to service bureaus running a ModelMaker-II on a per-piece basis. However, all successful jewelry sellers will have to have some access to this technology in the future.

Imagine the increased productivity of the goldsmith at the dawn of the 20th century with the invention of bottled gas and the flexible-shaft machine. Now imagine being the only jeweler trying to make jewelry without them! That's how profound CAD/CAM will be. For now, the early adopters can ensure their place in the rapidly changing industry architecture. Later, CAD/CAM will be just one more tool in the arsenal of the successful jeweler.

By Steven Pollack

Goldsmith Steven Pollack owns The Missing Link, a custom-jewelry studio in Glencoe, IL. His school, XYZ Academy, offers on-line classes in 3-D solid modeling using CAD for direct production of wax models using the Sanders ModelMakerII Rapid Prototyper. Contact him at (888) 300-8031,

Finished pieces the author created using CAD/CAM technology.
A CAD/CAM wax, cast and finished piece, prepared by Sanders Prototype, maker of the ModelMaker-II.

The ModelMaker-II is now used for computer-aided manufacture in more than 100 jewelry companies, including the author's. Though its cost is high ($66,900), manufacturer Sanders Prototype offers a 60-month lease and says the system pays for itself over time. Sanders Prototype Inc., Merrimack, NH; (603) 429-9700,

Copyright © 1999 by Bond Communications.


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