Tips on incorporating a robust hinge I'm working on a gadget a bit like a jewelry box. I want the lid on a hinge. Are 3d printed hinges robust enough for daily use long term? Perhaps with a metal pin? I want to incorporate the hinge into the design but my thinking is that it would be a waste of time if the hinge will break as I'd need to reprint the whole gadget.

You can make a print-in-place hinge as a horizontal cone with a 45-degree angle. The opposing face will be a similar conical hole with a 0.25 mm gap between the faces (or whatever your printer's tolerance needs to be).

The strength of this (as in the other answers) depends on the diameter of the hinge. The strength you need depends on how heavy the thing it holds up will be.

There are many parts on Thingiverse that use conical hinges like this if you need examples.

 which I split into parts and then arranged the hinged coupling next to the block it fits in. (Technically I suppose this is a frustrum. But things that come to a zero diameter pointy tip tend to not print well.)

There are 4 holes in the linkage, and the whole assembly is printed at once.