A rather simple doorknob to replace the old ones on my printer enclosure wall cupboard. You will need M4 nut and screw. Just slide the nut into the slot, and you can fit it to the door with the screw.
See https://www.thingiverse.com/thing:3586966 for a secure latch to fit with these doorknobs.
doorknob.stl | 133.7KB |