July 2000 Precious Metals & Bench/Metalsmithing Journey into CAD: Hinged-Hoop Solitaire Earrings Follow the process of creating earrings through computer-aided design Jewelers can use computer-aided design to create exclusive lines and custom work quickly and relatively inexpensively. Follow the steps in this project to make hinged-hoop solitaire earrings. The use of CAD allows for a high degree of precision, especially when it comes to crafting the hinges and lightening the weight. These earrings can be made in a variety of metals to lend different looks in a popular style. – by Steven Pollack Steven Pollack is a goldsmith with 10 years of experience creating unique jewelry designs. His school, XYZ Academy, offers on-line classes in 3-D solid modeling using computer-aided design for direct production of wax models using the Sanders Model Maker-II Rapid Prototyper. Contact him at (888) 300-8031, www.xyzacademy.com. 1. Lay Out a Circle Lay out a circle representing the inside circumference of the hoop. The setting is laid out as a two-dimensional closed line. 2. Extrude the Setting The setting is extruded 5mm and the corner segments are rounded. 3. Perform a Sweep Sweep the two shapes along the arc using the two-source sweep operation. 4. Make the Left Half The left half of the earring will be solid, created from a sweep of the rounded rectangle. 5. Rendered View 6. Subtract Weight The earring is lightened by creating and subtracting smaller solids from the inside. Rendered isometric view after the sweep, trim and mirror/copy operations. 7. Create Hinge A tube is extruded, superimposed between two halves of the earring and split into three sections. The two outside slices are unioned to the right half of the earring while the center slice is unioned to the left. A copy of each is subtracted from the opposite side to create the hinge opening. 8. The Perfect Match Because the same slices are used to create the male and female parts, this becomes – by definition – a perfect hinge. A smaller rod is subtracted from both earring halves to create the hinge pin hole.