Customizable corn sheller

Shelling corn is a chore done by hand in much of the rural developing world. Corn comes in different sizes - and the various [DIY shellers](https://www.engineeringforchange.org/news/2012/06/30/how_to_make_a_corn_sheller.html) are a major chore to make. Here you can either use the customizer app or the OpenSCAD to get the right size of sheller for your crop -- then print in plastic or metal.
This is an example of 3-D printable [open source appropriate technology](http://www.appropedia.org/imag