A PETG latch for an outdoor gate in the fence.

A very oversized version of a common door handle latch. Where regular latches I got at the hardware store wouldn't work right after several rain/dry cycles (even with a metal frame for the gate), this allows the gate to sag or rise.

The mechanism does not use any metal parts (except the mounting hardware), so there is nothing that would corrode in the rain. If in direct sunlight, the plastic may get damaged by the UV, so you can paint it or cover it with sticky aluminium tape.

The inside is lubricated with some silicone grease.

The latch is very wide (120mm), which should more than compensate for the lower strength of plastic comparing to metal.

I recommend printing with PETG. I don't think PLA would do well in the sun, and PLA springs work worse than PETG.

I printed it at 0.3mm layer height, 0.4mm line width, 3 wall lines, 15% gyroid infill.

The tolerances are wide enough so other settings should work fine.

Note that my gate opens towards the lock side, so that the stresses apply primarily to the gate frame, the wedge, and the 2x4 screwed to the fence post.

If you want to use it with a gate opening the other way, I recommend screwing a 2x4 over the lock body.