This will be 3D printed near you and delivered to your door by May 25
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....The test print shown was made in black PLA using a MakerGear M2 with a 0.25mm diameter extrusion and 25% fill in the larger flat regions. The part is 6.35mm (1/4 inch) thick with a 0.4mm gap between the separate parts printed assembled. There is only a little force needed to smoothly operate the hinge, although it will hold an open position; if yours operates rougher or sticks, consider using a larger gap setting.
Hinge Printable As An Assembled Unit Without Supports