When I moved in, I found this little white plastic clip thing marked “842” and had no idea what it was for, so I just tossed it in a bin of random house parts. About a year later I noticed my window screen was loose and I realized that the white clip was a pin that held the window screen in place and slid up and down to secure or release the screen. After replacing the pin, I noticed a few other window screens were also missing a pin. I managed to find the part online, but it comes with the whole corner latch assembly; you can't just buy the pin. Once I bought my 3D printer, I had the perfect model for my first ever CAD experience. I built this in Tinkercad, and from learning the controls to printing the final iteration took about 3 hours - not too bad for my first time!
The result is my very first CAD model, a weirdly specific locking pin for the window screens at my house, and maybe yours too!
The author marked this model as their own original creation.