DonÂ´t know if this is the first fabber part ever, but it was mine.
In 2003 the crank of my cheese grater broke. I liked the design and was not willing to waste it. But I had no idea where to get the spare part. So I decided in my christmas holidays 2003 to build it by myself. I designed an optimized version with turnable crank grip and built it in Alumide on a laser-sintering machine. It broke never again and is still in use. I looked on the save date of the original file: it is 01.01.2004.
Let me know if you know a documented case earlier.
If you like to do something similar with movable elements for laser-sintering, you should choose a gap width of 0.25 to 0.3mm. Furthermore, if possible, reduce the bearing surfaces to a minimum to ensure easy loosening of the elements and removal of loose powder. For a round axis for example you could design 3 small bearing surfaces around the axis in a distance of 120Â° instead of using just a circle-cross section.