Cat-Proof Foldable Door Latch (3D Printable Spring-Loaded Lock)

My cat kept figuring out how to open a foldable door, so I designed a simple mechanical latch to keep it securely closed while still allowing easy human operation. This is a compact, spring-loaded locking mechanism that mounts directly to the door frame and prevents the panel from being pushed open.

The latch uses a pivoting arm and compression spring to automatically lock into place when the door closes. To open the door, just press the lever and swing it free — quick, intuitive, and reliable

- Prevents pets from opening foldable or lightweight doors

- Spring-loaded auto-locking action

- Easy one-handed release

- Simple hardware (standard screws + spring)

You will need the following components:

- 2× 608 skateboard bearings

- 2× M3 screws long enough to fit through the two door mounts and the door

- 2× M3 locking nuts

- 4× M3 screws (about 10–15 mm) to hold the springs in place

- 3× M8 locking nuts

- 1× M8 screw, long enough to fit through the 2 latches, 3 M8 locking nuts, and the door

- 2× wood screws

Assembly

- Start by holding one of the covers to the door and mark where the M3 holes will be.

- Drill the holes for the M3 screws.

- Put one bearing in each cover and screw them to the door using the two M3 screws and locking nuts.

- Drill the 8 mm hole for the bolt .

- Put the M8 screw through one of the latches.

- Screw on one M8 locking nut.

- Insert it through the door.

- Secure it with one M8 locking nut.

- Place the second latch on the bolt .

- Screw on the third M8 locking nut to hold the latch in place.

- Attach a spring on each side by screwing them in place with the short screws.

- Close the door and mark where the catch needs to be.

- Screw the two catches to the door frame with wood screws.