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

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

2. Drill the holes for the M3 screws.

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

4. Drill the 8 mm hole for the bolt.

5. Put the M8 screw through one of the latches.

6. Screw on one M8 locking nut.

7. Insert it through the door.

8. Secure it with one M8 locking nut.

9. Place the second latch on the bolt.

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

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

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

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