3-D printing may be more advanced than I had thought:
I am a little bit skeptical. For example, how does the optical scanner determine the dimensions and configuration of individual internal parts, for which there is no line of sight? That is not explained in the video, though perhaps it’s a simplification for the casual viewer.
Nonetheless, what a great technology for off-world travel. No need for spare parts. Of course, you need a feed stock for the process that will meet the specifications for the end product, and it helps if that feedstock can be manufactured at your destination. We already know that we can make breathing air and rocket propellant from elements readily available on Mars, so why not other compounds?
I think the internal details question is discussed in the comments — there is substantial post-processing to turn the scanned shape into a functional wrench. I suspect they were simply accentuating the gee-whiz factor by omitting that part of the process.
It happens that there are much more advanced versions of this, which work with metals and not just plastics.