Difference Engine
thingiverse
The Difference Engine, created by Babbage, is capable of calculating polynomials. Check out this animated video for a better understanding: http://www.youtube.com/watch?v=8X6iIpjawZU. For building the engine, you will need several parts including the figure wheel (http://www.thingiverse.com/thing:7605), restore arm (http://www.thingiverse.com/thing:7610), sector wheel (http://www.thingiverse.com/thing:7711), sector wheel tab (http://www.thingiverse.com/thing:7712), and the sector wheel restore arm (http://www.thingiverse.com/thing:7713).
With this file you will be able to print Difference Engine with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Difference Engine.