Since I don’t have the energy to commercialize this, I’m posting it on here. If anyone does commercialize it or some derivative, you gotta give me a fair cut.
There’s products out there to prevent toddlers from locking themselves in rooms by preventing the door to close all the way. This also helps make sure no tiny fingers get smashed in the door jambs. To add to that problem, our toddler liked closing the door to the room with the catboxes in it, or getting in this room and trying to play with the litter. This led to multiple accidents by the cats when we didn’t realize their door was shut for a whole day or so. and multiple close calls of our baby touching cat turds.
To fix this, I doodled up a door latch in Fusion 360 that would prevent the door from being shut too much so the cats can get in, but not open enough for a toddler to fit though. I 3D printed it on a Dremel 3d20 printer. I had at first attempted to print this in parts since it was so long, but regardless of how I made the interlocking mechanism, it always failed in one way or another. After about 5 attempts, I printed a single slightly shorter version with 40% infill and a handful of shells. This was strong indeed!
It worked well until a guest came over and slammed the door. Oh well. We had it for about a year which did the task of training the baby for the most part. We’ll still catch the door closed every once in a whole, but have only had one accident because of it.