So I wanted a small, and thin friction hing for another project, and I couldn't find the metal ones that they use for the iPad's Magic Keyboard case. So I design my own the parts I had on my desk.
The smallest nut that I had was 4mm wide which really limited how thick the design can be. The result is this
It folds flat at measure at a maximum thickness of about 10mm
It works a lot better than I thought it would, especially since this is my first prototype print. Need to figure out some things, like to stiffen the arms and to prevent/reduce twisting.
But as a basis to start from this works nicely. I think if I add a TPU washer on the back end, I might be able to get it stiffer and more consistent feeling. But I'll do that at another time.
What about a dab of hot glue as a kind of medium between the head of a bolt/screw and the plastic it’s in?
This way you get some of the “grip” from a malleable material that’s also pretty easy to get ahold of for most people.