Chốt Cổng Tự Đóng (Self-Closing Gate Latch)

This is a simple self-closing latch mechanism for a gate or door. Generally, the latch attaches to the door while the catch is on the frame or post, but it can be applied vice-versa. 

The piece, when using a high percentage of infill, has enough mass to fall back down into the latch. There is a 1mm clearance.

I've also included an option to attach a ¼" fibreglass rod and extend the lever access. This is a pretty specfic application in my case where there's 4 steps up to the gate, and it would be easier if the release latch could be accessed lower down on the gate rather than reaching all the way at the top. 

The screw slots on the latch are 5mm wide, with 11mm clearance for the screw head and/or washer. On the catch they're 4mm, and a M4 screw will fit in the holes just fine.

Inside the latch is a hole for a M3x15 for a bit of reinforcement, but it's likely not necessary.