Professional Jeweler Archive: Journey into CAD

February 2000

Precious Metals & Bench/Metalsmithing

Journey into CAD

Follow the process of creating a ring through computer-aided design

One benefit of using computer-aided design is the precision with which you can create jewelry before you get to the model stage.

You can create and print a full-color, high-resolution rendering of what the jewelry will look like – an extremely helpful advantage when doing custom work for a client. You can easily show the rendering to the customer for approval or revision.

In the following example, the eternity ring’s modeling took an hour and a half to complete. After the rendering, a rapid-prototyping program, such as Sanders Model Maker-II, can build the three models into castable waxes in about six hours.

–by Steven Pollack

Steven Pollack is a goldsmith with 10 years of experience creating unique designs. His school, XYZ Academy, offers on-line classes in 3-D solid modeling using CAD for direct production of wax models using the Sanders Model Maker-II Rapid Prototyper. Contact him at (888) 300-8031,

The Project:
In this project, CAD will be used to create this eternity-style ring in a size 6.
Create a Sphere:
In the CAD program, create a 3.2mm sphere. Move the sphere up the X axis 8.3mm, the radius of a size 6 ring. Accommodate different finger sizes by changing this parameter using the CAD software on your computer.
Design a Cutting Tool for the Pilot Hole:
The gems to be set in the ring are 2mm or 0.03 carat. Create a cutting tool for the pilot hole and seat by extruding two cylinders. Make the smaller cylinder for the pilot hole 0.8mm in diameter and the larger one for the seat 1.2mm in diameter. These dimensions will leave metal so the seat can be cut with a setting bur.
Bevel and Join:
Next, bevel the bottom face of the 1.2mm seat cylinder.
Then join the two cylinders to make one.
Superimpose on the Sphere:
Next, superimpose the cutting tool onto the sphere using your CAD software.
Create the Pilot Hole:
Using the difference operation, create a predrilled pilot hole and bearing to hold a stone in the sphere.
Make Multiple Copies:
Make 12 copies of the sphere with pilot hole by entering 12 into the multicopy dialogue box in the CAD software. Rotate the copies around the axis until the element returns to its original position.
Make a Connector Piece:
Make a connector piece from an extruded cylinder. Multicopy it 12 times and rotate around the axis.
Join the Elements:
Join the 24 elements to create a single solid object. Copy the solid object twice and rotate the copies around the axis slightly so they are offset.
Create a Rendering:
Superimpose gemstone models on the rings and render them as rubies and diamonds. Give the bands attributes of gold and platinum. Place a solid block beneath with the attributes of a mirror to create a high-quality rendering you can show your client before production begins.

Copyright © 2001 by Bond Communications