About this 3D model
Here's a simple hinge design that does not violate the 45 degree overhang limit rule -- no spans either. The hinge mechanism uses conical pins on the narrow fingers mating with conical hollows in the thick fingers. This makes a very cleanly operating hinge which goes between a flat 180 and 90 degree positions, and is easy to print. For now, this is just a test/demo using the customizer; a more parametric version is coming....