Engravers design coins in 3-D
- By Kathleen Hickey
- Aug 19, 2008
The U.S. Mint is creating coin designs using an innovative 3-D modeling technology that enables engravers to design coins using haptic, or touch, capabilities, allowing interactivity in real time with virtual objects. Engravers can feel the coin's surface as they design on-screen just as they would if they were working with wax or clay.
The Mint is creating the front side of the 2008 bald eagle half-dollar; the front side of the 2008 James Monroe dollar coin; the reverse side of the 2008 Louisa Adams $10 gold coin and the reverse side of the 2008 Arizona state quarter using the FreeForm 3-D modeling system from SensAble Technologies.
Designs are created using a stylus-like haptic device instead of a computer mouse. The system is tailored for creating curved, organic and non-geometric shapes.
The technology is faster and more efficient than traditional engraving methods and eliminates quality lost in duplicating wax or clay models. Additionally, it uses common digital design steps such as undo, cut, copy and paste; imports 3-D scans of source data; transfers 2-D or 3-D designs into relief (the part of a coin design that is raised above its surface); and allows users to save and review multiple versions as well as add detail and textures with precision. Files can be imported and exported in the STL data format, allowing designs to be saved and forwarded to computer numerical control machines for engraving.
Designs created with the technology include:
- On the bald eagle half-dollar coin, a baby eagle in the foreground against a background of the U.S. flag;
- On the James Monroe dollar coin, a likeness of the fifth president, including prominent cheekbones and chin; and
- On the Louisa Adams $10 gold coin, an image of the former first lady (1825-29) and her son, Charles, in front of Arc de Triomphe-style arches.
Kathleen Hickey is a freelance writer for GCN.