Tripod Camera Mount Quick Release Plate
I bought a tripod for $9 from a swap meet as I wanted to use it with my dslr. However, it was missing the quick release plate that attaches to the base of the camera and slots into the tripod.
I decided this was a great challenge for my 3D printer so I crafted one in openscad (file to follow when I can find it).
One of the dimensions is a bit too long (I believe the basic insert shape should be a square but I ran out of plastic to retry.)