Working with a CAD/CAM Provider

A model approach to developing a good relationship

By Rachel V. Katz

Find a Suitable Partner

If you’re just starting out, take the following steps to find a vendor who can fulfill your needs:

Determine your CAD/CAM needs. Do you need someone who can take your drawing from concept to completion—creating the CAD file, building the model, and casting the piece? Or do you create the CAD designs yourself and need only model building services? Figure out exactly what you need and make sure the service bureau you are considering can cover all the bases.

Research potential vendors. The best place to start to learn about a company’s experience is on its Web site, which should clearly inform you of the processes and equipment it uses. Many CAD/CAM firms handle a variety of industries, from aerospace to dentistry, so check to make sure they have jewelry experience, preferably with a bench jeweler on staff. A service bureau without jewelry industry experience may be able to design jewelry in CAD and produce models, but it needs to know the jewelry world if it’s going to help you engineer a workable piece of jewelry.

Learn some basics. Familiarize yourself with the equipment and processes used at the service bureau so you can have a more informed conversation about the work being done on your design. Does the service bureau have the capability to do both additive (building a model from the bottom up using rapid prototyping) and subtractive (milling a wax model down to form) modeling? While in most cases you should rely on the bureau’s expertise when it comes to choosing the appropriate model making method, it helps you play a more active role if you have some knowledge of the technology and processes.

Pay Attention to Details

Once you’ve found your partner, you can’t just send your design to the service bureau, forget about it, and then assume your model will come back perfect. The more information you provide and the better communication you maintain, the more likely you’ll receive the model you expect. Here are some things to always keep in mind:

Be specific about your design. Most service bureaus listed the following specifications as the minimum amount of information they need to get started on your CAD design:

• Ring size. Unlike waxes, resin-based models can’t just be trimmed off if the ring size needs to be reduced. Make sure you indicate the correct size from the get-go.

• Metal. Knowing the color will help the designer produce an accurate, full-color rendering. For very intricate pieces, such as those with latticework, the metal may also determine aspects of the design. For example, you may face a higher risk of gaps in an intricate design cast in platinum. If the CAD designer is aware of this, there might be a way to design more places for the metal to flow in and out.

Other relevant details include stone weights and measurements, shank thickness, and prong thickness. Write everything down before you approach a bureau, and then share your information.

Remember that a picture is worth a thousand words. The more visual information you can provide—a sketch, a catalog image of a piece that resembles the model you envision—the better. If you want an existing piece modified, send along the piece if possible. If you need to accommodate specific stone sizes, send along the stones as well, if possible. Again, the more information you can provide up front, the better.

Identify the manufacturer. If your model is headed to a manufacturer, let the service bureau know who that is. Many companies have their own way of doing things—some require models of a certain thickness, others want to apply their own gates—and enabling your subcontractor to speak to the manufacturer or production supervisor may help to avoid complications.

Date your submissions. Include a date on your sketches so that the design bureau knows exactly when it came in. This will also be able to help to determine the progression of the job, if several versions go back and forth.

Rely on the bureau’s expertise… When turning a hand-drawn design into a CAD file, or when building a model from a CAD file, the service bureau may find structural issues that require anything from a small tweak to a larger redesign—or you may find your idea didn’t quite translate as well as you had hoped. If you’ve picked a good partner, you should be able to express your intent while understanding some of the technical limitations that might require a different approach.

…And share your own. Offer ideas to the CAD designer that will make your overall production process easier. Your service bureau might suggest casting an item as a single piece, but if you feel you’ll do a better polishing job with two components, bring that issue up.

Watch for errors. Examine your design carefully to make sure there are no gaps or errors that may require the service bureau to send it back or spend time fixing it before sending it for modeling.

Think scale. Even if you’ve provided intricate details and exact dimensions, your grandiose idea may not be possible: The enlarged nature of CAD drawings can sometimes make the impossible seem plausible. Sometimes what may seem wonderful on the screen will, in real life, be too tiny to accommodate a gemstone—or even be seen by the human eye.

Recognize the strength in numbers. If your jewelry item includes a number of identical pieces, see if your provider can build several models rather than one that you’ll need to mold.

Look carefully at the renderings. Take more than a passing glance at every detail in the rendering. If it includes wording, make sure everything is spelled correctly. Sounds basic, but many jobs have been saved by taking that one last look.

Have Realistic Expectations

Even the quickest, most innovative CAD/CAM technology will disappoint if you have unrealistic expectations about its speed, its capabilities, and its costs. To avoid this, always keep in mind the following:

Don’t expect instant gratification. Even “rapid” prototyping takes time. A service bureau may have to wait for a machine to free up, or it may want to gather several pieces in order to make the most efficient use of a machine’s platform, where the models are built. In general, the average turnaround runs a few days to a week for designing and model building, with up to another week for molding and casting services. Also, watch the calendar and ask about capacity when placing orders.

Know what you’re paying for. Working with CAD/CAM, you’ll be paying for the designer as well as the time it takes the machine to build the model. The more detail you provide in your sketch, the less guesswork you leave to the CAD designer, and potentially the quicker the job gets done. A more intricate design, such as a pavé setting, will likely require more design time.

You should discuss payment terms ahead of time so you understand what you’re paying for. For example, you should know the following:

• Does the service bureau charge by the hour or have a flat fee?

• How is time tracked?

• If a rendering doesn’t come out the way you’d like and you make changes, will the time spent on the redesign be included?

Asking such questions—and keeping the lines of communication open throughout the entire process—will help to ensure that your and your vendor can develop not just a long and healthy relationship, but a true partnership.