Here's a hand tool for making miters and chops in small materials. Good for model building, doll house trim, etc. It uses a common utility knife blades and 4-40 screws. The model is in inches so scale by 25.4 for Millimeters if necessary and the knife blades will fit well.
7-9-15 Update- I accidentally exported with too high a resolution for the geometry. The files now are much liter.