Basic hinge, 1.75mm filament hole

Print out two of these and they'll make a full hinge. Clip out some filament slightly smaller than the width of the hinge, and crimp one end, then thread through the uncrimped end until you can't push anymore. Then, just press down on a solid surface, and you're got a hinge!

Meets dimensions for Butler Tray Hinge Round Edge 2-1/2"x1-1/2" - with Screws