It appears the 3D printer on the International Space Station is no longer in use.
You may recall the groundbreaking experiment sponsored by NASA and executed by California-based Made In Space to develop a 3D printer capable of operating in the microgravity environment in orbit. They were indeed successful, as a desktop-sized unit was custom designed to handle the peculiarities of that environment. It was launched to the station in late 2014, installed and operated successfully.
Our last information about the device was from this past April, when NASA revealed their preliminary analysis of prints obtained from the orbiting 3D printer. At the time, the prints were presumed to meet or exceed the expected specifications.
Now, however, we receive information from someone as close to the action as you could be: Astronaut Scott Kelly, who happens to be spending no less than a solid year in orbit. Kelly recently participated in a Reddit Q&A (“AMA”) session in which he was asked about the 3D printer. The thought was that if a 3D printer was on board, surely it must be used for printing any required doodads in the course of station operations. Kelly replied:
We do have a 3D printer, but I haven't seen it. It is packed away and we haven't used it since I have been here. Hopefully we will use it soon!
Aha. So the printer is actually no longer operating! Evidently it was packed up very soon after the first tests, as Kelly arrived in March 2015.
This is actually not surprising, as the International Space Station is a very busy scientific lab, where operating space is most definitely at a premium, with Earth-based researchers competing strongly for the right to run their experiments on the ISS. Without specific use requirements, it’s doubtful the 3D printer would remain ready for action. In fact, it was itself an experiment.
NASA does everything by plan, and if the plan does not have 3D printing in it, it’s likely not going to take place. At this stage in the lifecycle of space-based 3D printing, they are probably preparing for the next step, having completed the first one successfully.