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.
I could achieve the same effect by making the arms thicker. Though I am thinking of printing the screw caps in TPU to see if I can make it stiffer that way.
Trying to keep the parts the same as the main thing this belongs too. M2 threaded inserts and 5mm screws. So not a lot of flexibility when it comes to thickness. That said, as a MK2 I'd probably make it 2mm thick rather than 1.2mm since that's my goto size for stiffness.
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.