Helps you put a consistent angle on your knife's cutting edge.

STLs are sized for a 50x200x25mm stone and 2mm blade width, see scad if your stone or blade is a different size.

Add a drop of oil in the channels to reduce friction and wear.

Scad requires tbuser's openscad-bitmap library from http://github.com/tbuser/openscad-bitmap (also linked as ancestor) which is used to write the angle on the car.