I've printed at least a dozen of these boxes now in various sizes. I've adjusted my recent ones so the hinge is a little more lose. They print easy and the hinge swings freely straight away. The hinge is also very strong, I haven't broke one yet. This also depends on wall thickness, since a strong hinge needs walls at least 1.5mm or so. You can also simply make the hinge stronger by increasing the diameter of it and printing 100% infill, using the openscad file.