Here's a simple latch I made in one print on the Ultimaker 3 Printer. I used a layer height of .2 and an Infill of 70%. It's stiff at first but once you move it around and break apart the support in the middle, it works perfectly.
Hinge.SLDPRT | 306.3KB | |
Hinge_Assy.SLDPRT | 117.0KB | |
Hinge_Assy.STL | 326.4KB |