A relatively inconspicuous detail the old Revell designers hadn’t thought to include in the kit was the ship’s bell. Not finding anything suitable in my spare parts box, I’d have normally gone to the local model railroad shop to find something. This time, though, I thought I’d try something new: 3D printing.
3D printing (also known as rapid prototyping) is a process of making a three-dimensional solid object from a virtual CAD representation with a materials printer using digital technology. The shape is built up through an additive process where successive layers of material (in this case resin) are laid down in different shapes to form the object rather than the traditional method of removing excess material to produce the shape. I found an outfit called Shapeways (
http://www.shapeways.com) that offers this service, and a quick search yielded “EMD Roof Mount Locomotive Bells”. Based on a Southern Pacific SD-45 prototype in N-Scale, these measured .962cm w x .456cm d x .424cm h (.379in w x .18in d x .167in h) – perfect for a 1/232 Olympia ship’s bell!
The bells arrived attached to a frame matrix similar to the sprues on injection molded plastic parts. The material ("frosted ultra detail UV cured acrylic polymer") is similar to the polyurethane resin commonly used in model shipbuilding; solid but also easy to work. The shapes are flawless, and the little step artifacts of the layering process are so small as to be virtually invisible. They do, however, make a useful key for paint.
Fitted to a .015 inch plastic strip mount attached to a couple of the cowl vents, the 3D printed bell looks right at home among all those Old School injection molded plastic parts.