12 April 2022
Outdoor Box Latch
We live in an area that frequently sees high winds, and has several outdoor boxes for storage and for package pickup and delivery. I designed this part to solve the problem of needing the boxes to be latched closed when not in use, but not require the removal of any clips or opening of any latches to use the boxes. In particular, I wanted our mail delivery people to be able to simply open and close the box with a single motion and not have to know how or remember to latch anything when leaving.
Having these boxes securely closed at all times helps me sleep at night and avoids potential wind-induced damage when we are out of town.
- Fusion 360
The hole for the steel shaft will have to be reamed out with a drill bit.
Attach the strike plate for the latch to the lower body. This is provided in two pieces so the latch mechanism can be tuned or replaced, and for support free printing.
Insert spring into the top housing and handle simultaneously and hold it together while inserting the steel shaft. Secure the steel shaft by inserting two M3 machine screws in the holes on the underside of the handle. Be careful not to strip out these holes, the screws only need to barely bite into the shaft to prevent it from coming back out.
Attach the handle to the lid and the latch to the base of the box. You might need spacers to get the alignment right as many boxes have different overhangs for the lid.
Check the movement of the system to ensure it opens and closes freely, there should be no rubbing and the latch should slide over and catch the strike plate with minimal effort and without needing to actuate it by hand (the lid should be able to fall freely and latch on its own).
I used a steel linear rod from an old 3d printer since it was what I had laying around, but have since found that it rusts in the rain. I would recommend using an aluminum or brass rod instead.