The objective behind this project was to create a 3D CAD model of the Arithmometer, a 19th century calculating machine. The Arithmometer was first built in 1820 by Thomas de Colmar and could perform addition, subtraction, multiplication and division. It was the first machine of this kind to receive commercial success. Although machines still exist today, they are mostly in museums and are too costly for the casual collector. Through the use of rapid prototyping, the CAD model we provide could be used to print a copy of the device at a fraction of the cost of an original machine.