Function

The insulated timber composter has a hinged lid with gas struts. The printed hinges replace wooden ones that failed. 

The design provides only the non-moving barrel of the hinge, because the moving barrel is a metal collar in the lid's sidewall.

The pins are M8 studs. These have nuts and washers gripping the plastic barrel, so the pin doesn't rotate within it (the pivoting occurs between pin and lid).

Recommendations

• Print in ASA for outdoor use (I just used PLA+, but annealed, varnished and painted them).
   
• Use 25% minimum infill;  1.6 mm minimum walls.
   
• Overhang the box lid's covering to reduce the effects of rain and sun on the hinges.
   
• Make a small (≈2mm) chamfer on the box outer corner where the hinge mounts.
   
• Add some thick polyethene sheet (or closed-cell foam membrane) under the hinge piece, to “bed it down” and mitigate uneven contact with the box rim.

FreeCAD source model provided ☺

FreeCAD users could quite easily modify it for other projects.