Inner Bevel for abitrary shapes in OpenSCAD

thingiverse

This OpenSCAD module computes an inner bevel for any 3D model, requiring specification of the z-plane height for bevel creation. Replace the provided part() with your own design; credit goes to GregFrost's idea (http://www.thingiverse.com/thing:135408) for outer bevel on arbitrary shapes. The method involves minkowski() operations on a small square and the original shape, followed by subtraction to create an outline, then another minkowski() with the bevel's form. However, beware of limitations: it can be slow due to repeated minkowski() and hull(), so keep 2D shapes' $fn low. Minkowski() isn't implemented for disjoint forms or 2D objects with holes. Be aware that this works only for parts perpendicular to the plane where the bevel will sit. Happy designing!