If you missed the Maker Faire Bay Area: NASA was showing the 3D printer used on the ISS. One of the things the astronauts printed was a backscratcher with a modular design. The print files may be “released in the future”.
I’ve seen it at previous events, but they wouldn’t open it. This time it was open, but the guy standing next to it said I couldn’t take pictures of the inside, though I got a good enough look to build a pretty complete BOM of the interesting parts in my head.
@Whosa_whatsis I asked the woman explaining me the printer, if it is ok to take pictures, I got a simple and plain “yes”.
Not bad prints at all. Still some of the same slicing artifacts on home machines, but nice.
I wonder if overhangs are less of a problem in space. 
Thermals might be an interesting variable in space. Your forced air cooling fan may have unexpected impact on overall thermal control for the space station.
@Mike_Miller Based on all the press photos, the printer operates fully enclosed, with a larger box off the side that presumably contains environmental/thermal controls/filtration, and it’s also kept sealed up in a glove box.
What sort of drive mechanism does it use for each axis? I’d guess ball screws
@Mike_Miller That’s what they looked like to me, tiniest ballscrews I’ve ever seen.
Every gram counts. Those look like titanium smooth rod holders as well.